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Sample records for bulletin stamford ct

  1. Stamford, Connecticut: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Registered Energy Companies in Stamford, Connecticut Clean Diesel Technologies Inc International Plasma Sales Group IPSG Natural State Research, Inc. Noble Americas...

  2. Stamford, Connecticut: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Connecticut 4 References Registered Energy Companies in Stamford, Connecticut Clean Diesel Technologies Inc International Plasma Sales Group IPSG Natural State Research, Inc....

  3. DOE - Office of Legacy Management -- Dorr Corp - CT 14

    Office of Legacy Management (LM)

    Dorr Corp - CT 14 FUSRAP Considered Sites Site: Dorr Corp. (CT.14 ) Eliminated from consideration under FUSRAP - Referred to NRC Designated Name: Not Designated Alternate Name: Dorr - Oliver Corporation CT.14-2 Location: 737 Canal Street , Stamford , Connecticut CT.14-2 Evaluation Year: 1990 CT.14-3 Site Operations: Conducted heat treatment tests of source material using depleted uranium in an enclosed calciner CT.14-2 Site Disposition: Eliminated - No Authority - AEC licensed CT.14-3

  4. DOE - Office of Legacy Management -- American Cyanamid Co - CT 13

    Office of Legacy Management (LM)

    Cyanamid Co - CT 13 FUSRAP Considered Sites Site: American Cyanamid Co (CT.13 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Stamford , Connecticut CT.13-1 Evaluation Year: 1987 CT.13-1 Site Operations: Produced boron and possibly handled small amounts of refined radioactive source material circa 1940's. Also possibly performed research work on irradiated "J" slugs in 1952 and 1953. CT.13-1 CT.13-3 Site Disposition:

  5. OCRWM Bulletin

    SciTech Connect (OSTI)

    1996-04-01

    This document is the Winter 1996 ORCWM Bulletin which is a report from the U.S. Department of Energy`s Office of Civilian Radioactive Waste Management. Budget considerations and a discussion of waste policy forums are described. Several articles about the on-going site characterization at Yucca Mountain are included as a part of this bulletin.Tunnel excavations, meteorology studies, effects of seismic events, and design of a conveyor belt system are some of the topics covered in this issue.

  6. JC3 High Impact Assessment Bulletins | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High Impact Assessment Bulletins JC3 High

  7. JC3 Low Impact Assessment Bulletins | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Low Impact Assessment Bulletins JC3 Low

  8. JC3 Medium Impact Assessment Bulletins | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Medium Impact Assessment Bulletins JC3 Medium

  9. Monthly Project Bulletin: October 2012

    Broader source: Energy.gov [DOE]

    This document contains the Guidelines for Home Energy Professionals Project bulletin for the month of September 2012.

  10. Monthly Project Bulletin: August 2012

    Broader source: Energy.gov [DOE]

    This document contains the Guidelines for Home Energy Professionals Project bulletin for the month of August 2012.

  11. U-009:Microsoft Security Bulletin Summary for October 2011

    Broader source: Energy.gov [DOE]

    Microsoft released 8 bulletins to address vulnerabilities. This Microsoft bulletin contains 2 critical vulnerabilities.

  12. Environmental guidance regulatory bulletin

    SciTech Connect (OSTI)

    1997-01-31

    This document describes the background on expanding public participation in the Resource Conservation and Recovery Act and DOE`s response. The bulletin also describes the changes made by the final rule to existing regulations, guidance provided by EPA in the preamble and in the revised RCRA Public Participation Manual, the relationship between public participation and environmental justice, and DOE`s recent public participation and environmental justice initiatives.

  13. Final Information Quality Bulletin for Peer Review | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Final Information Quality Bulletin for Peer Review Final Information Quality Bulletin for Peer Review Final Information Quality Bulletin for Peer Review PDF icon Final Information ...

  14. U-124: Microsoft Security Bulletin Advance Notification for March 2012

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for March 2012. Microsoft has posted 1 Critical Bulletin, 4 Important bulletins and 1 Moderate bulletin. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow remote execution of code. Microsoft is hosting a webcast to address customer questions on these bulletins on March 14, 2012, at 11:00 AM Pacific Time (US & Canada).

  15. U-256: Microsoft Security Bulletin Advance Notification for September 2012

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for September 2012. Microsoft has posted 0 Critical Bulletins and 2 Important Bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow remote execution of code. Microsoft is hosting a webcast to address customer questions on these bulletins on September 12, 2012, at 11:00 AM Pacific Time (US & Canada).

  16. V-023: Microsoft Security Bulletin Advance Notification for November 2012

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for November 2012. Microsoft has posted 4 Critical Bulletins and 1 Important Bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow remote execution of code.Microsoft will host a webcast to address customer questions on the security bulletins on November 14, 2012, at 11:00 AM Pacific Time (US & Canada).

  17. U-209: Microsoft Security Bulletin Advance Notification for July 2012

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for July 2012. Microsoft has posted 3 Critical Bulletins and 6 Important Bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow remote execution of code. Microsoft is hosting a webcast to address customer questions on these bulletins on July 11, 2012, at 11:00 AM Pacific Time (US & Canada).

  18. U-189: Microsoft Security Bulletin Advance Notification for June 2012

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for June2012. Microsoft has posted 3 Critical Bulletins and 4 Important Bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow remote execution of code. Microsoft is hosting a webcast to address customer questions on these bulletins on May 13, 2012, at 11:00 AM Pacific Time (US & Canada).

  19. U-145: Microsoft Security Bulletin Summary for April 2012

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Summary for April 2012. Microsoft has posted 4 Critical Bulletins and 2 Important bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow remote execution of code. Microsoft is hosting a webcast to address customer questions on these bulletins on April 11, 2012, at 11:00 AM Pacific Time (US & Canada).

  20. V-064: Microsoft Security Bulletin Advance Notification for January 2013

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for January 2013 . Microsoft has posted 2 Critical Bulletins and 5 Important Bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow remote execution of code. Microsoft will host a webcast to address customer questions on the security bulletins on January 9, 2013, at 11:00 AM Pacific Time (US & Canada).

  1. U-278: Microsoft Security Bulletin Advance Notification for October 2012

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for October 2012. Microsoft has posted 1 Critical Bulletins and 6 Important Bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow remote execution of code. Microsoft is hosting a webcast to address customer questions on these bulletins on October 10, 2012, at 11:00 AM Pacific Time (US & Canada).

  2. V-042: Microsoft Security Bulletin Advance Notification for December 2012

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for December 2012. Microsoft has posted 5 Critical Bulletins and 2 Important Bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow remote execution of code. Microsoft will host a webcast to address customer questions on the security bulletins on December 12, 2012, at 11:00 AM Pacific Time (US & Canada).

  3. Monthly Project Bulletin: September 2012 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    September 2012 Monthly Project Bulletin: September 2012 This document contains the Guidelines for Home Energy Professionals Project bulletin for the month of September 2012. septemberbulletin.pdf (112.86 KB) More Documents & Publications Monthly Project Bulletin: July 2012 Monthly Project Bulletin: August 2012 Monthly Project Bulletin: October

  4. V-130: Microsoft Security Bulletin Advance Notification for April 2013

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for April 2013. Microsoft has posted 2 Critical Bulletins and 7 Important Bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow remote execution of code. Microsoft will host a webcast to address customer questions on the security bulletins on April 10, 2013, at 11:00 AM Pacific Time (US & Canada).

  5. V-108: Microsoft Security Bulletin Advance Notification for March 2013

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for March 2013. Microsoft has posted 4 Critical Bulletins and 3 Important Bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow remote execution of code. Microsoft will host a webcast to address customer questions on the security bulletins on March 13, 2013, at 11:00 AM Pacific Time (US & Canada).

  6. V-154: Microsoft Security Bulletin Advance Notification for May 2013

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for May 2013. Microsoft has posted 2 Critical Bulletins and 8 Important Bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow remote execution of code. Microsoft will host a webcast to address customer questions on the security bulletins on May 15, 2013, at 11:00 AM Pacific Time (US & Canada).

  7. V-175: Microsoft Security Bulletin Advance Notification for June 2013

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for June 2013. Microsoft has posted 1 Critical Bulletin and 4 Important Bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" June allow remote execution of code. Microsoft will host a webcast to address customer questions on the security bulletins on June 12, 2013, at 11:00 AM Pacific Time (US & Canada).

  8. V-196: Microsoft Security Bulletin Advance Notification for July 2013

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for July 2013. Microsoft has posted 6 Critical Bulletin and 1 Important Bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" July allow remote execution of code. Microsoft will host a webcast to address customer questions on the security bulletins on July 10, 2013, at 11:00 AM Pacific Time (US & Canada).

  9. V-088: Microsoft Security Bulletin Advance Notification for February 2013

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for February 2013. Microsoft has posted 5 Critical Bulletins and 7 Important Bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow remote execution of code. Microsoft will host a webcast to address customer questions on the security bulletins on February 13, 2013, at 11:00 AM Pacific Time (US & Canada).

  10. U-057: Microsoft Security Bulletin Advance Notification for December 2011

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for December 2011. Microsoft has posted 3 Critical Bulletins and 11 Important bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow propagation of Internet worm without user action. Microsoft will host a webcast to address customer questions on the security bulletins on December 14, 2011, at 11:00 AM Pacific Time (US & Canada).

  11. U-235: Microsoft Security Bulletin Advance Notification for August 2012

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for August 2012. Microsoft has posted 5 Critical Bulletins and 4 Important Bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow remote execution of code. Microsoft is hosting a webcast to address customer questions on these bulletins on August 15, 2012, at 11:00 AM Pacific Time (US & Canada).

  12. U-164: Microsoft Security Bulletin Advance Notification for May 2012

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for May 2012. Microsoft has posted 3 Critical Bulletins and 4 Important Bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow remote execution of code. Microsoft is hosting a webcast to address customer questions on these bulletins on May 8, 2012, at 11:00 AM Pacific Time (US & Canada).

  13. U-103: Microsoft Security Bulletin Advance Notification for February 2012

    Broader source: Energy.gov [DOE]

    Microsoft Security Bulletin Advance Notification for February 2012. Microsoft has posted 6 Critical Bulletins and 5 Important bulletins. Bulletins with the Maximum Severity Rating and Vulnerability Impact of "Critical" may allow remote execution of code. Microsoft is hosting a webcast to address customer questions on these bulletins on February 15, 2012, at 11:00 AM Pacific Time (US & Canada).

  14. Monthly Project Bulletin: January 2012 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    January 2012 Monthly Project Bulletin: January 2012 This document contains the Guidelines for Home Energy Professionals Project bulletin for the month of January 2012. PDF icon ...

  15. Monthly Project Bulletin: February 2012 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    February 2012 Monthly Project Bulletin: February 2012 This document contains the Guidelines for Home Energy Professionals Project bulletin for the month of February 2012. PDF icon ...

  16. Monthly Project Bulletin: April 2012 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    April 2012 Monthly Project Bulletin: April 2012 This document contains the Guidelines for Home Energy Professionals Project bulletin for the month of April 2012. PDF icon ...

  17. Monthly Project Bulletin: March 2012 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    March 2012 Monthly Project Bulletin: March 2012 This document contains the Guidelines for Home Energy Professionals Project bulletin for the month of March 2012. PDF icon ...

  18. Final Information Quality Bulletin for Peer Review

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    04 OFFICE OF MANAGEMENT AND BUDGET Final Information Quality Bulletin for Peer Review INTRODUCTION This Bulletin establishes that important scientific information shall be peer reviewed by qualified specialists before it is disseminated by the federal government. We published a proposed Bulletin on September 15, 2003. Based on public comments, we published a revised proposal for additional comment on April 28, 2004. We are now finalizing the April version, with minor revisions responsive to the

  19. Final Information Quality Bulletin for Peer Review

    Energy Savers [EERE]

    ... and trends (e.g., unemployment and poverty rates) is excluded from this Bulletin. ... and trends (e.g., unemployment and poverty rates); 6. accounting, budget, actuarial, ...

  20. Monthly Project Bulletin: August 2012

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    August 2012 This bulletin is your monthly source for project updates on the U.S. Department of Energy (DOE) Guidelines for Home Energy Professionals project. This issue is dedicated to the new Home Energy Professional certifications and covers: * Pilot Certification: Be One of the First to be Certified * Free Home Energy Professional Certification Pilot Exams Available for Current and Former WAP Workers * Finding a Testing Center Near You * Upcoming Conferences and Events * Project Testimonial *

  1. Monthly Project Bulletin: February 2012

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    February 2012 This bulletin is your monthly source for regular updates on the U.S. Department of Energy (DOE) Guidelines for Home Energy Professionals project. This issue covers: * Pilot Certification Program Coming Soon * Manufactured Housing Standard Work Specifications Industry Review Open Through February 10, 2012 * Upcoming Conferences and Events * About the Project Pilot Certification Program Coming Soon The Guidelines for Home Energy Professionals team is set to launch a pilot

  2. Monthly Project Bulletin: January 2012

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    January 2012 This bulletin is your monthly source for regular updates on the U.S. Department of Energy (DOE) Guidelines for Home Energy Professionals project. This issue covers: * Unveiling a New Commenting Tool * Manufactured Housing Standard Work Specifications Industry Review * Upcoming Conferences and Events * About the Project Unveiling a New Commenting Tool The Guidelines for Home Energy Professionals team is excited to introduce a new commenting tool designed to streamline industry and

  3. Monthly Project Bulletin: July 2012

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    July 2012 This bulletin is your monthly source for project updates on the U.S. Department of Energy (DOE) Guidelines for Home Energy Professionals project. This issue covers:  Pilot Certification: Registration Still Open  On-Demand Pilot Certification Orientation Webinars  Update on Voluntary Standard Work Specifications for Single-Family Energy Upgrades  Upcoming Conferences and Events  Project Testimonial  About the Project Pilot Certification: Registration Still Open

  4. Monthly Project Bulletin: May 2012

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    May 2012 This bulletin is your monthly source for project updates on the U.S. Department of Energy (DOE) Guidelines for Home Energy Professionals project. This issue covers: * Pilot Certification Open: Register Now * Crew Leader Certification: Changing the Game * Update on Voluntary Standard Work Specifications * Upcoming Conferences and Events * Project Testimonial * About the Project Pilot Certification Open: Register Now Registration for the four new Home Energy Professional certifications is

  5. Monthly Project Bulletin: October 2012

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    October 2012 This bulletin is your monthly source for project updates on the U.S. Department of Energy (DOE) Guidelines for Home Energy Professionals project. This issue covers: * New Deadlines Announced for Pilot Certification * Video View of the Weatherization Assistance Program * Project Testimonial * Upcoming Conferences and Events * About the Project New Deadlines Announced for Pilot Certification Due to strong demand for the Energy Auditor and Quality Control (QC) Inspector certification

  6. Monthly Project Bulletin: July 2012 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    July 2012 Monthly Project Bulletin: July 2012 This document contains the Guidelines for Home Energy Professionals Project bulletin for the month of July 2012. julybulletin.pdf (195.26 KB) More Documents & Publications Monthly Project Bulletin: March 2012 Monthly Project Bulletin: June

  7. Monthly Project Bulletin: June 2012 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    June 2012 Monthly Project Bulletin: June 2012 This document contains the Guidelines for Home Energy Professionals Project bulletin for the month of June 2012. junebulletin.pdf (120.96 KB) More Documents & Publications Monthly Project Bulletin: August 2012 Monthly Project Bulletin: July

  8. California State Fire Marshal Information Bulletin

    Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

    California State Fire Marshal Information Bulletin April 27, 2009 INFORMATION REGARDING PLACEMENT OF E85 FUEL DISPENSING EQUIPMENT ON STATE OWNED OR STATE LEASED FACILITIES In an effort to assist interested parties with criteria addressing E85 dispensing equipment, the Office of the State Fire Marshal (OSFM) is providing this informational bulletin. E85 is the acronym for an alcohol-blended gasoline fuel that contains between 15 to 85 percent ethanol (alcohol). Presently, there are over 10,000

  9. Technology applications bulletins: Number one

    SciTech Connect (OSTI)

    Koncinski, W. Jr.

    1989-02-01

    Martin Marietta Energy Systems, Inc. (Energy Systems), operates five facilities for the US Department of Energy (DOE): the Oak Ridge National Laboratory (ORNL), which is a large, multidisciplinary research and development (R and D) center whose primary mission is energy research; the Oak Ridge Y-12 Plant, which engages in defense research, development, and production; and the uranium-enrichment plants at Oak Ridge; Paducah, Kentucky; and Portsmouth, Ohio. Much of the research carried out at these facilities is of interest to industry and to state or local governments. To make information about this research available, the Energy Systems Office of Technology Applications publishes brief descriptions of selected technologies and reports. These technology applications bulletins describe the new technology and inform the reader about how to obtain further information, gain access to technical resources, and initiate direct contact with Energy Systems researchers.

  10. Y-12 Bulletin Uranium Articles | Y-12 National Security Complex

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Bulletin Uranium ... Y-12 Bulletin Uranium Articles Posted: July 22, 2013 - 3:13pm | Y-12 Report | Volume 10, Issue 1 | 2013 These and other articles can be found in archived ...

  11. T-533: Microsoft January 2011 Security Bulletin Release

    Broader source: Energy.gov [DOE]

    Microsoft released 2 bulletins to address 3 vulnerabilities involving Microsoft Windows and components in Windows OS, and Windows Server Releases. Only 1 of these bulletins get our maximum severity rating of Critical.

  12. T-599: Microsoft April 2011 Security Bulletin Release

    Broader source: Energy.gov [DOE]

    Microsoft released 17 bulletins to address vulnerabilities involving Microsoft Office Suites and Software in Windows OS. This Microsoft Bulletin contains 9 Critical vulnerabilities which require a restart after the applied patch.

  13. Monthly Project Bulletin: May 2012 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    May 2012 Monthly Project Bulletin: May 2012 This document contains the Guidelines for Home Energy Professionals Project bulletin for the month of May 2012. PDF icon maybulletin.pdf ...

  14. U-078: Microsoft Security Bulletin Advance Notification for January 2012 |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy 78: Microsoft Security Bulletin Advance Notification for January 2012 U-078: Microsoft Security Bulletin Advance Notification for January 2012 January 10, 2012 - 8:15am Addthis PROBLEM: Microsoft Security Bulletin Advance Notification for January 2012. PLATFORM: Windows Server 2008 R2, Windows 7, Windows Server 2008, Windows Vista, Windows Server 2003, Windows XP ABSTRACT: Microsoft Security Bulletin Advance Notification for January 2012. Microsoft has posted 1 Critical

  15. T-665: Microsoft Security Bulletin Advance Notification for July 2011

    Office of Energy Efficiency and Renewable Energy (EERE)

    Microsoft released 4 bulletins to address vulnerability involving Microsoft Office Suites and Software in Windows OS. This Microsoft Bulletin contains 1 Critical vulnerabilities which require a restart after the applied patch. The Exploitability Index, displays both CVE and Microsoft bulletin ID associated to vulnerability.

  16. Monthly Project Bulletin: November/December 2012 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    November/December 2012 Monthly Project Bulletin: November/December 2012 This document contains the Guidelines for Home Energy Professionals Project bulletin for the months of November/December 2012. nov_decbulletin.pdf (128.75 KB) More Documents & Publications Monthly Project Bulletin: October

  17. T-584: Microsoft March 2011 Security Bulletin Release

    Broader source: Energy.gov [DOE]

    Microsoft released 3 bulletins to address vulnerabilities involving Microsoft Office Suites and Software in Windows OS. This Microsoft Bulletin contains 1 Critical vulnerabilities which require a restart after the applied patch. The Exploitability Index, displays both CVE and Microsoft bulletin ID associated to vulnerability.

  18. T-553: Microsoft February 2011 Security Bulletin Release

    Broader source: Energy.gov [DOE]

    Microsoft released 21 bulletins to address vulnerabilities involving Microsoft Office Suites and Software in Windows OS. This Microsoft Bulletin contains 3 Critical vulnerabilities which require a restart after the applied patch. The Exploitability Index, displays both CVE and Microsoft bulletin ID associated to vulnerability.

  19. JC3 Bulletin Archive | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    JC3 Bulletin Archive JC3 Bulletin Archive RSS September 9, 2013 V-237: TYPO3 Security Bypass Vulnerabilities TYPO3 comes with the possibility to restrict editors to certain file actions (copy, delete, move etc.) and to restrict these actions to be performed in certain locations September 6, 2013 V-236: MediaWiki CentralAuth Extension Authentication Bypass Vulnerability A vulnerability has been reported in the CentralAuth extension for MediaWik that allows people to bypass certain security

  20. T-645: Microsoft Security Bulletin Advance Notification

    Broader source: Energy.gov [DOE]

    Microsoft provides the Microsoft Security Bulletin Advance Notification Service. This advance notification is intended to help our customers plan for effective deployment of security updates, and includes information about the number of new security updates being released, the software affected, severity levels of vulnerabilities, and information about any detection tools relevant to the updates.

  1. Classification Bulletin GEN-16 Revision 2 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Bulletin GEN-16 Revision 2 Classification Bulletin GEN-16 Revision 2 Provides guidance to DOE Federal and contractor employees with access to classified information on appropriate actions when classified information (i.e., Restricted Data (RD), Formerly Restricted Data (FRD), Transclassified Foreign Nuclear Information (IFNI), National Security Information (NSI)) appears in the open literature and to clarify the circumstances that constitute comment. Classification Bulletin GEN-16 Revision 2

  2. Briefing, Classification Bulletin GEN-16 - October 2014 | Department...

    Broader source: Energy.gov (indexed) [DOE]

    No Comment Policy on Classified Information in the Open Literature This briefing provides information on Classification Bulletin GEN-16, No Comment Policy on Classified Information ...

  3. Environmental Bulletin The Savannah River Site

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Bulletin The Savannah River Site On January 25, 2016, the Department of Energy (DOE) issued a Notice of Availability (NOA) of its draft Environmental Assessment (EA) (DOE/EA-1977) evaluating the potential environmental impacts from a proposed action to receive, store, process and disposition spent nuclear fuel (SNF) from the Federal Republic of Germany at DOE's Savannah River Site (SRS) (Draft Spent Nuclear Fuel from Germany EA). In that previous Notice, DOE invited public comments on the Draft

  4. Monthly Project Bulletin: November/December 2012

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    December 2012 This bulletin is your monthly source for project updates on the U.S. Department of Energy (DOE) Guidelines for Home Energy Professionals project. This issue covers: * Updated Prerequisites for the Home Energy Professional Certifications * New Pilot Certification Exam Deadlines * Multifamily SWS Review Period is Closing * Project Testimonial * About the Project Updated Prerequisites for the Home Energy Professional Certifications The prerequisite high school diploma/GED requirement

  5. January 2012 ARRA Energy Assurance Planning Bulletin Available

    Broader source: Energy.gov [DOE]

    The Department released the January 2012 issue of the ARRA Energy Assurance Planning Bulletin (EAPB). The ARRA EAPB is issued quarterly to provide information on energy assurance planning resources, upcoming events, training opportunities, and important grant deliverable dates. This is the ninth issue of the EAP Bulletin; previous issues are available for download.

  6. July 2012 ARRA Energy Assurance Planning Bulletin Available

    Broader source: Energy.gov [DOE]

    The Department released the July 2012 issue of the ARRA Energy Assurance Planning Bulletin (EAPB). The ARRA EAPB is issued quarterly to provide information on energy assurance planning resources, upcoming events, training opportunities, and important grant deliverable dates. This is the eleventh issue of the EAP Bulletin; previous issues are available for download.

  7. April 2012 ARRA Energy Assurance Planning Bulletin Available

    Broader source: Energy.gov [DOE]

    The Department released the April 2012 issue of the ARRA Energy Assurance Planning Bulletin (EAPB). The ARRA EAPB is issued quarterly to provide information on energy assurance planning resources, upcoming events, training opportunities, and important grant deliverable dates. This is the tenth issue of the EAP Bulletin; previous issues are available for download.

  8. RUS Bulletin 1794-A-603: Scoping Guide | Open Energy Information

    Open Energy Info (EERE)

    3: Scoping Guide Jump to: navigation, search OpenEI Reference LibraryAdd to library PermittingRegulatory Guidance - Inner-Office Memorandum: RUS Bulletin 1794-A-603: Scoping...

  9. Unconventional petroleum: a current awareness bulletin

    SciTech Connect (OSTI)

    Grissom, M.C.

    1983-10-30

    The summaries in this bulletin cover both secondary and tertiary recovery of petroleum and the following topics under Oil Shales and Tar Sands: reserves and exploration; site geology and hydrology; drilling, fracturing, and mining; oil production, recovery, and refining; properties and composition; direct uses and by-products; health and safety; marketing and economics; waste research and management; environmental aspects; and regulations. These summaries and older citations to information on petroleum, oil shales, and tar sands back to the 1960's are available for on-line searching and retrieval on the Energy Data Base using the DOE/RECON system or commercial on-line retrieval systems. Retrospective searches can be made on any aspect of petroleum, oil shales, or tar sands, or customized profiles can be developed to provide current information for each user's needs.

  10. T-688: McAfee Security Bulletin - McAfee SaaS Endpoint Protection...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Security Bulletin - McAfee SaaS Endpoint Protection update fixes multiple ActiveX issues T-688: McAfee Security Bulletin - McAfee SaaS Endpoint Protection update fixes multiple...

  11. Policy Bulletin 4, Change 1, Exemption 2 Guidance | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Policy Bulletin 4, Change 1, Exemption 2 Guidance Policy Bulletin 4, Change 1, Exemption 2 Guidance The purpose of this bulletin is to provide guidance on which Freedom of Information Act (FOIA) exemption should be used as the basis for marking security-related information currently protected as Official Use Only (OUO) under "Exemption 2, Circumvention of Statute," in DOE Classification Guides. Policy Bulletin, POL-4, Change 1, Exemption 2 Guidance (403.7 KB) More Documents &

  12. Bulletin, Fire Prevention Measures For Cutting, Welding, And Related Activities

    Broader source: Energy.gov [DOE]

    The purpose of this Bulletin is to summarize existing DOE and industry requirements, standards,and guidelines that are applicable to hot work and related activities that represent a significant fire risk to DOE and contractor personnel, programs, and facilities. [DOE/EH-0196 Issue No.97-3

  13. How to design and establish a computer bulletin board to support inventors

    SciTech Connect (OSTI)

    Not Available

    1991-12-31

    This booklet is a ``how-to handbook`` to demonstrate the development of an interactive electronic bulletin board as a support network for independent inventors and small business inventors. This will explain step-by-step, how Linking Alaskan Minds{trademark}, the Alaskan model of an interactive computer bulletin board system, was developed and designed to serve as a successfully working, interactive computer bulletin board that links and supports independent inventors in Alaska.

  14. How to design and establish a computer bulletin board to support inventors

    SciTech Connect (OSTI)

    Not Available

    1991-01-01

    This booklet is a how-to handbook'' to demonstrate the development of an interactive electronic bulletin board as a support network for independent inventors and small business inventors. This will explain step-by-step, how Linking Alaskan Minds{trademark}, the Alaskan model of an interactive computer bulletin board system, was developed and designed to serve as a successfully working, interactive computer bulletin board that links and supports independent inventors in Alaska.

  15. Now Available: July 2011 issue of the Energy Assurance Planning Bulletin

    Broader source: Energy.gov [DOE]

    This quarter's issue of the Energy Assurance Planning Bulletin highlights upcoming DOE/OE Regional Exercises, Recipient Action Items, and success stories.

  16. State of Michigan Bulletin Regarding E85 Fuel Dispensers

    Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

    State Fire Marshal Bulletin 11 E-85 Fuel Dispensers We have become aware of the lack of an approved national standard for the dispensers and connected appurtenances involved in the dispensing of fuel, which contains more than 15% alcohol (E-85). The Michigan State Fire Code currently requires all dispensing equipment to be listed by a nationally recognized testing laboratory; however, since there is no standard, no listing can currently be placed on these systems. We have discussed this issue

  17. DOE-Flex Bulletin-Worker Injury While on a DOE-Flex Arrangement |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy DOE-Flex Bulletin-Worker Injury While on a DOE-Flex Arrangement DOE-Flex Bulletin-Worker Injury While on a DOE-Flex Arrangement This bulletin responds to questions that have surfaced regarding DOE's liability for an injury to an employee while working at an alternative workplace, particularly at home. It is the position of the DOE Office of General Council that the case decision cited in this document should be relied upon as the prevailing administrative law at this

  18. DOE-Flex Bulletin-Worker Injury While on a DOE-Flex Arrangement

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Flex Bulletin The information contained in this Bulletin is intended for DOE-Flex Advisors and Coordinators in responding to questions. The information supplements the guidance in the Handbook on DOE- Flex and will be incorporated in the handbook in the near future, at which fime this Builetin wil! expire and be removed from the DOE-Flex web site No. 2 May 2000 Subject: Worker In~jury While on a DOE-Flex Arrangement This Bulletin responds to questions that have surfaced regarding DOE'S liability

  19. NETL CT Imaging Facility

    SciTech Connect (OSTI)

    2013-09-04

    NETL's CT Scanner laboratory is equipped with three CT scanners and a mobile core logging unit that work together to provide characteristic geologic and geophysical information at different scales, non-destructively.

  20. NETL CT Imaging Facility

    ScienceCinema (OSTI)

    None

    2014-05-21

    NETL's CT Scanner laboratory is equipped with three CT scanners and a mobile core logging unit that work together to provide characteristic geologic and geophysical information at different scales, non-destructively.

  1. DOE's Safety Bulletin No. 2011-01, Events Beyond Design Safety Basis

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Analysis, March 2011 | Department of Energy DOE's Safety Bulletin No. 2011-01, Events Beyond Design Safety Basis Analysis, March 2011 DOE's Safety Bulletin No. 2011-01, Events Beyond Design Safety Basis Analysis, March 2011 PURPOSE This Safety Alert provides information on a safety concern related to the identification and mitigation of events that may fall outside those analyzed in the documented safety analysis. BACKGROUND On March 11, 2011, the Fukushima Daiichi nuclear power station in

  2. 1989 OCRWM [Office of Civilian Radioactive Waste Management] Bulletin compilation and index

    SciTech Connect (OSTI)

    1990-02-01

    The OCRWM Bulletin is published by the Department of Energy, Office of Civilian Radioactive Waste Management to provide current information about the national program for managing spent fuel and high-level radioactive waste. This document is a compilation of issues from the 1989 calendar year. A table of contents and one index have been provided to assist in finding information contained in this year`s Bulletins. The pages have been numbered consecutively at the bottom for easy reference. 7 figs.

  3. The American Recovery and Reinvestment Act (ARRA) Energy Assurance Planning (EAP) Bulletin, January 3 2011, Volume 2 No. 1

    Broader source: Energy.gov [DOE]

    The American Recovery and Reinvestment Act (ARRA) Energy Assurance Planning (EAP) Bulletin provides information on energy assurance planning resources, upcoming events, training opportunities, and...

  4. The American Recovery and Reinvestment Act (ARRA) Energy Assurance Planning (EAP) Bulletin, July 1 2011, Volume 2 No. 3

    Broader source: Energy.gov [DOE]

    The American Recovery and Reinvestment Act (ARRA) Energy Assurance Planning (EAP) Bulletin provides information on energy assurance planning resources, upcoming events, training opportunities, and...

  5. The American Recovery and Reinvestment Act (ARRA) Energy Assurance Planning (EAP) Bulletin, April 1 2011, Volume 2 No. 2

    Broader source: Energy.gov [DOE]

    The American Recovery and Reinvestment Act (ARRA) Energy Assurance Planning (EAP) Bulletin provides information on energy assurance planning resources, upcoming events, training opportunities, and...

  6. The American Recovery and Reinvestment Act (ARRA) Energy Assurance Planning (EAP) Bulletin, October 3 2011, Volume 2 No. 4

    Broader source: Energy.gov [DOE]

    The American Recovery and Reinvestment Act (ARRA) Energy Assurance Planning (EAP) Bulletin provides information on energy assurance planning resources, upcoming events, training opportunities, and...

  7. DOE - Office of Legacy Management -- Seymour CT Site - CT 02

    Office of Legacy Management (LM)

    Seymour CT Site - CT 02 FUSRAP Considered Sites Seymour, CT Alternate Name(s): Bridgeport Brass Company Seymour Specialty Wire Reactive Metals, Inc. National Distillers and Chemical Co. Havens Plant CT.02-2 CT.02-3 CT.02-6 Location: 15 Franklin Street, Seymour, Connecticut CT.02-4 Historical Operations: Procured, processed and stored uranium oxides, salts, and metals for AEC and processed the products by cold-forming or extruding natural uranium metal. CT.02-3 CT.02-9 Eligibility Determination:

  8. Classification Bulletin GEN-16, Revision 2, No Comment Poly on Classified Information in the Open Literature

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    3, 2014 MEMORANDUM FORDISTRl ~N fJJ!}/, 'ViJ ~ FROM: A~~s?oVokdKES DIRECTOR OFFICE OF CLASSIFICATION OFFICE OF ENVIRONMENT, HEALTH, SAFETY AND SECURITY SUBJECT: Classification Bulletin GEN-16, REVISION 2, "No Comment" Policy on Classified Information in the Open Literature Classification Bulletin GEN-16, Revision 1, '"NO COMMENT' POLICY ON CLASSIFIED INFORMATION IN THE PUBLIC DOMAIN," has been updated to address concerns regarding documents marked as classified in the open

  9. CT Solar Lease

    Broader source: Energy.gov [DOE]

    CT Solar Lease allows homeowners to lease a photovoltaic (PV) or solar thermal system, with fixed monthly payments, for a term of 20 years, at no upfront down payment.* This program, which takes...

  10. CT Solar Loan

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Clean Energy Finance and Investment Authority is offering a pilot loan program, CT Solar Loan, to provide homeowners with 15-year loans for solar PV equipment. The loans are administered...

  11. Closeout of IE Bulletin 80-12: decay heat removal system operability

    SciTech Connect (OSTI)

    Foley, W.J.; Dean, R.S.; Hennick, A.

    1985-06-01

    On April 19, 1980, decay heat removal (DHR) capability was lost at Davis-Besse 1 for approximately two and one-half hours in a refueling mode. Typically for that mode, many systems and components were out of service for maintanance and testing or were deactivated to preclude inadvertent actuation. IE Bulletin 80-12 was issued May 9, 1980 for action by licensees of operating pressurized water reactors (PWRs); it was issued for information to nuclear power facilities other than operating PWRs. The intent of the bulletin ws to improve nuclear plant safety by reducing the likelihood of losing DHR capability in PWRs, especially when some DHR components are unavailable because of maintenance activities during refueling and cold shutdown modes of operation. A related NRR Generic Letter was issued June 11, 1980 to licensees of operating PWRs, requesting amendment of technical specifications to ensure long-term maintenance of DHR capability. Evaluation of utility responses and NRC/IE inspection reports indicates that the bulletin can be closed out per specific criteria for 33 (75%) of the 44 affected facilities.

  12. CT Offshore | Open Energy Information

    Open Energy Info (EERE)

    Jump to: navigation, search Name: CT Offshore Place: Otterup, Denmark Zip: 5450 Sector: Wind energy Product: Denmark-based consultancy which provides assistance for project...

  13. Siemens Corporate Technology CT | Open Energy Information

    Open Energy Info (EERE)

    Corporate Technology CT Jump to: navigation, search Name: Siemens Corporate Technology (CT) Place: Erlangan, Germany Sector: Solar Product: R&D lab for Siemens AG. Currently...

  14. The FELICIA bulletin board system and the IRBIS anonymous FTP server: Computer security information sources for the DOE community. CIAC-2302

    SciTech Connect (OSTI)

    Orvis, W.J.

    1993-11-03

    The Computer Incident Advisory Capability (CIAC) operates two information servers for the DOE community, FELICIA (formerly FELIX) and IRBIS. FELICIA is a computer Bulletin Board System (BBS) that can be accessed by telephone with a modem. IRBIS is an anonymous ftp server that can be accessed on the Internet. Both of these servers contain all of the publicly available CIAC, CERT, NIST, and DDN bulletins, virus descriptions, the VIRUS-L moderated virus bulletin board, copies of public domain and shareware virus- detection/protection software, and copies of useful public domain and shareware utility programs. This guide describes how to connect these systems and obtain files from them.

  15. Closeout of IE Bulletin 83-05: ASME nuclear code pumps and spare parts manufactured by the Hayward Tyler Pump Company

    SciTech Connect (OSTI)

    Foley, W.J.; Dean, R.S.; Hennick, A. )

    1990-08-01

    Documentation is provided in this report to close IE Bulletin 83-05 regarding ASME nuclear code pumps and spare parts manufactured by the Hayward Tyler Pump Company (HTPC). The bulletin was issued (1) to alert holders of operating licenses and construction permits of nuclear power plants that HTPC failed to implement effectively their quality assurance (QA) program from 1977 to 1981 and (2) to require affected utilities to take action to resolve the potential for failure of the subject pumps and their spare parts. Evaluation of utility responses and NRC/Region inspection reports shows that reliability of the affected pumps was ensured by means of procedures and performance testing of the pumps as required by the bulletin. Based on the evaluation, in accordance with specific criteria, the bulletin is closed for 116 (98%) of the 118 facilities to which it was issued for action and which were not shut down indefinitely or permanently at the time of issuance of this report. A follow-up item is proposed for the two facilities with open bulletin status. Based on favorable results, a conclusion is presented to indicate that the bulletin concerns have been resolved.

  16. Category:Bridgeport, CT | Open Energy Information

    Open Energy Info (EERE)

    in this category, out of 16 total. SVFullServiceRestaurant Bridgeport CT Connecticut Light & Power Co.png SVFullServiceRestauran... 64 KB SVQuickServiceRestaurant Bridgeport CT...

  17. CT Investment Partners LLP | Open Energy Information

    Open Energy Info (EERE)

    CT Investment Partners LLP Jump to: navigation, search Name: CT Investment Partners LLP Place: London, United Kingdom Zip: WC2A 2AZ Sector: Carbon Product: Venture capital arm of...

  18. Dual energy CT for attenuation correction with PET/CT

    SciTech Connect (OSTI)

    Xia, Ting; Alessio, Adam M.; Kinahan, Paul E.

    2014-01-15

    Purpose: The authors evaluate the energy dependent noise and bias properties of monoenergetic images synthesized from dual-energy CT (DECT) acquisitions. These monoenergetic images can be used to estimate attenuation coefficients at energies suitable for positron emission tomography (PET) and single-photon emission computed tomography (SPECT) imaging. This is becoming more relevant with the increased use of quantitative imaging by PET/CT and SPECT/CT scanners. There are, however, potential variations in the noise and bias of synthesized monoenergetic images as a function of energy. Methods: The authors used analytic approximations and simulations to estimate the noise and bias of synthesized monoenergetic images of water-filled cylinders with different shapes and the NURBS-based cardiac-torso (NCAT) phantom from 40 to 520 keV, the range of SPECT and PET energies. The dual-kVp spectra were based on the GE Lightspeed VCT scanner at 80 and 140 kVp with added filtration of 0.5 mm Cu. The authors evaluated strategies of noise suppression with sinogram smoothing and dose minimization with reduction of tube currents at the two kVp settings. The authors compared the impact of DECT-based attenuation correction with single-kVp CT-based attenuation correction on PET quantitation for the NCAT phantom for soft tissue and high-Z materials of bone and iodine contrast enhancement. Results: Both analytic calculations and simulations displayed the expected minimum noise value for a synthesized monoenergetic image at an energy between the mean energies of the two spectra. In addition the authors found that the normalized coefficient of variation in the synthesized attenuation map increased with energy but reached a plateau near 160 keV, and then remained constant with increasing energy up to 511 keV and beyond. The bias was minimal, as the linear attenuation coefficients of the synthesized monoenergetic images were within 2.4% of the known true values across the entire energy range

  19. Dual energy CT for attenuation correction with PET/CT

    SciTech Connect (OSTI)

    Xia, Ting; Alessio, Adam M.; Kinahan, Paul E.

    2014-01-15

    Purpose: The authors evaluate the energy dependent noise and bias properties of monoenergetic images synthesized from dual-energy CT (DECT) acquisitions. These monoenergetic images can be used to estimate attenuation coefficients at energies suitable for positron emission tomography (PET) and single-photon emission computed tomography (SPECT) imaging. This is becoming more relevant with the increased use of quantitative imaging by PET/CT and SPECT/CT scanners. There are, however, potential variations in the noise and bias of synthesized monoenergetic images as a function of energy. Methods: The authors used analytic approximations and simulations to estimate the noise and bias of synthesized monoenergetic images of water-filled cylinders with different shapes and the NURBS-based cardiac-torso (NCAT) phantom from 40 to 520 keV, the range of SPECT and PET energies. The dual-kVp spectra were based on the GE Lightspeed VCT scanner at 80 and 140 kVp with added filtration of 0.5 mm Cu. The authors evaluated strategies of noise suppression with sinogram smoothing and dose minimization with reduction of tube currents at the two kVp settings. The authors compared the impact of DECT-based attenuation correction with single-kVp CT-based attenuation correction on PET quantitation for the NCAT phantom for soft tissue and high-Z materials of bone and iodine contrast enhancement. Results: Both analytic calculations and simulations displayed the expected minimum noise value for a synthesized monoenergetic image at an energy between the mean energies of the two spectra. In addition the authors found that the normalized coefficient of variation in the synthesized attenuation map increased with energy but reached a plateau near 160 keV, and then remained constant with increasing energy up to 511 keV and beyond. The bias was minimal, as the linear attenuation coefficients of the synthesized monoenergetic images were within 2.4% of the known true values across the entire energy range

  20. DOE - Office of Legacy Management -- American Brass Co - CT 01

    Office of Legacy Management (LM)

    Brass Co - CT 01 FUSRAP Considered Sites Site: American Brass Co (CT.01 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: Anaconda Company Brass Division CT.01-1 Location: 414 Meadow Street , Waterbury , Connecticut CT.01-1 Evaluation Year: 1986 CT.01-2 Site Operations: Limited work with copper clad uranium billets during the 1950s. CT.01-1 Site Disposition: Eliminated - Potential for contamination considered remote based upon the limited scope of

  1. DOE - Office of Legacy Management -- New Canaan Site - CT 08

    Office of Legacy Management (LM)

    Canaan Site - CT 08 FUSRAP Considered Sites Site: NEW CANAAN SITE (CT.08) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: New Canaan , Connecticut CT.08-1 Evaluation Year: 1985 CT.08-2 Site Operations: None; Investigation of area prompted by public query; no site found in New Canaan. CT.08-1 Site Disposition: Eliminated - No AEC site located in this city CT.08-2 Radioactive Materials Handled: No Primary Radioactive Materials Handled: None

  2. DOE - Office of Legacy Management -- Torrington Co - CT 09

    Office of Legacy Management (LM)

    Torrington Co - CT 09 FUSRAP Considered Sites Site: TORRINGTON CO. (CT.09 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: Torrington Co. - Specialties Division CT.09-1 Location: Torrington , Connecticut CT.09-1 Evaluation Year: 1987 CT.09-1 Site Operations: Performed swaging experiments on small quantities of uranium rods circa 1951 to 1953 as a subcontractor to Bridgeport Brass Co. CT.09-1 Site Disposition: Eliminated - Potential for contamination

  3. Predix and Robots in CT Systems | GE Global Research

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Robots and Predix make Beijing's CT factory brilliant Guoshuang Cai 2015.04.16 GE Healthcare's Beijing plant is one of the largest factories producing computed tomography (CT) ...

  4. DOE - Office of Legacy Management -- Combustion Engineering Co - CT 03

    Office of Legacy Management (LM)

    Combustion Engineering Co - CT 03 FUSRAP Considered Sites Site: Combustion Engineering, CT (CT.03 ) Cleanup in progress by U.S. Army Corps of Engineers. Designated Name: Combustion Engineering Alternate Name: CE Site Asea Brown Boveri S1C Prototype CT.03-1 Location: 1000 Prospect Hill Road, Windsor, Connecticut CT.03-2 Evaluation Year: 1994 CT.03-1 Site Operations: Used natural, enriched, and highly enriched uranium to make fuel assemblies for the AEC. CT.03-3 CT.03-4 Site Disposition: Eligible

  5. DOE - Office of Legacy Management -- Sperry Products Inc - CT 07

    Office of Legacy Management (LM)

    Sperry Products Inc - CT 07 FUSRAP Considered Sites Site: SPERRY PRODUCTS, INC. (CT.07) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Danbury , Connecticut CT.07-1 Evaluation Year: 1994 CT.07-2 Site Operations: Performed tests involving non-destructive inspection techniques in the 1950s. CT.07-3 Site Disposition: Eliminated - Potential for contamination considered remote based on the limited scope of activities performed at the site

  6. DOE - Office of Legacy Management -- Wesleyan University - CT 12

    Office of Legacy Management (LM)

    Wesleyan University - CT 12 FUSRAP Considered Sites Site: Wesleyan University (CT.12 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Middletown , Connecticut CT.12-1 Evaluation Year: 1995 CT.12-2 Site Operations: Spectrographic research on small quantities of uranium wire (several inches in length) in Physics Department circa late 1950. CT.12-1 Site Disposition: Eliminated - Potential for contamination considered remote due to the

  7. Closeout of IE Compliance Bulletin 86-03: Potential failure of multiple ECCS (Emergency Core Cooling System) pumps due to single failure of air-operated valve in minimum flow recirculation line

    SciTech Connect (OSTI)

    Foley, W.J.; Dean, R.S.; Hennick, A. )

    1990-10-01

    Documentation is provided in this report for the closeout of IE Compliance Bulletin 86-03 regarding the potential failure of multiple Emergency Core Cooling System (ECCS) pumps due to a single failure of an air-operated valve in a minimum flow recirculation line. Closeout is based on the implementation and verification of four actions required by the bulletin. Evaluation of utility responses and NRC/Region inspection reports in accordance with specific criteria indicates that the bulletin is closed for 116 (98%) of the 118 nuclear power facilities in operation or under construction to which it was issued for action. Facilities which were shut down indefinitely or permanently or which had construction halted indefinitely were not included in this review. A follow-up item is proposed for the two (2) facilities with open bulletin status. It is concluded that the bulletin concern has been resolved, pending closeout by the NRC of Zion 1,2. Background information is provided in the Introduction and Appendix A.

  8. Comparison of CT and MR-CT Fusion for Prostate Post-Implant Dosimetry

    SciTech Connect (OSTI)

    Maletz, Kristina L.; Ennis, Ronald D.; Ostenson, Jason; Pevsner, Alexander; Kagen, Alexander; Wernick, Iddo

    2012-04-01

    Purpose: The use of T2 MR for postimplant dosimetry (PID) after prostate brachytherapy allows more anatomically accurate and precise contouring but does not readily permit seed identification. We developed a reproducible technique for performing MR-CT fusion and compared the resulting dosimetry to standard CT-based PID. Methods and Materials: CT and T1-weighted MR images for 45 patients were fused and aligned based on seed distribution. The T2-weighted MR image was then fused to the aligned T1. Reproducibility of the fusion technique was tested by inter- and intraobserver variability for 13 patients. Dosimetry was computed for the prostate as a whole and for the prostate divided into anterior and posterior sectors of the base, mid-prostate, and apex. Results: Inter- and intraobserver variability for the fusion technique showed less than 1% variation in D90. MR-CT fusion D90 and CT D90 were nearly equivalent for the whole prostate, but differed depending on the identification of superior extent of the base (p = 0.007) and on MR/CT prostate volume ratio (p = 0.03). Sector analysis showed a decrease in MR-CT fusion D90 in the anterior base (ratio 0.93 {+-}0.25, p < 0.05) and an increase in MR-CT fusion D90 in the apex (p < 0.05). The volume of extraprostatic tissue encompassed by the V100 is greater on MR than CT. Factors associated with this difference are the MR/CT volume ratio (p < 0.001) and the difference in identification of the inferior extent of the apex (p = 0.03). Conclusions: We developed a reproducible MR-CT fusion technique that allows MR-based dosimetry. Comparing the resulting postimplant dosimetry with standard CT dosimetry shows several differences, including adequacy of coverage of the base and conformity of the dosimetry around the apex. Given the advantage of MR-based tissue definition, further study of MR-based dosimetry is warranted.

  9. "EMM Region","PC","IGCC","PC","Conv. CT","Adv. CT","Conv. CC...

    U.S. Energy Information Administration (EIA) Indexed Site

    Regional cost adjustments for technologies modeled by NEMS by Electric Market Modul ... CT","Conv. CC","Adv. CC","Adv. CC wCCS","Fuel Cell","Nuclear","Biomass","MSW","On-shore ...

  10. Implications of CT noise and artifacts for quantitative {sup 99m}Tc SPECT/CT imaging

    SciTech Connect (OSTI)

    Hulme, K. W.; Kappadath, S. C.

    2014-04-15

    Purpose: This paper evaluates the effects of computed tomography (CT) image noise and artifacts on quantitative single-photon emission computed-tomography (SPECT) imaging, with the aim of establishing an appropriate range of CT acquisition parameters for low-dose protocols with respect to accurate SPECT attenuation correction (AC). Methods: SPECT images of two geometric and one anthropomorphic phantom were reconstructed iteratively using CT scans acquired at a range of dose levels (CTDI{sub vol} = 0.4 to 46 mGy). Resultant SPECT image quality was evaluated by comparing mean signal, background noise, and artifacts to SPECT images reconstructed using the highest dose CT for AC. Noise injection was performed on linear-attenuation (μ) maps to determine the CT noise threshold for accurate AC. Results: High levels of CT noise (σ ∼ 200–400 HU) resulted in low μ-maps noise (σ ∼ 1%–3%). Noise levels greater than ∼10% in 140 keV μ-maps were required to produce visibly perceptible increases of ∼15% in {sup 99m}Tc SPECT images. These noise levels would be achieved at low CT dose levels (CTDI{sub vol} = 4 μGy) that are over 2 orders of magnitude lower than the minimum dose for diagnostic CT scanners. CT noise could also lower (bias) the expected μ values. The relative error in reconstructed SPECT signal trended linearly with the relative shift in μ. SPECT signal was, on average, underestimated in regions corresponding with beam-hardening artifacts in CT images. Any process that has the potential to change the CT number of a region by ∼100 HU (e.g., misregistration between CT images and SPECT images due to motion, the presence of contrast in CT images) could introduce errors in μ{sub 140} {sub keV} on the order of 10%, that in turn, could introduce errors on the order of ∼10% into the reconstructed {sup 99m}Tc SPECT image. Conclusions: The impact of CT noise on SPECT noise was demonstrated to be negligible for clinically achievable CT parameters. Because

  11. Chest wall invasion by lung cancer: limitations of CT evaluation

    SciTech Connect (OSTI)

    Pennes, D.R.; Glazer, G.M.; Wimbish, K.J.; Gross, B.H.; Long, R.W.; Orringer, M.B.

    1985-03-01

    Thirty-three patients with peripheral pulmonary malignancies contiguous with a pleural surface were evaluated for chest wall invasion by computed tomography (CT). CT criteria included pleural thickening adjacent to the tumor, encroachment on or increased density of the extrapleural fat, asymmetry of the extrapleural soft tissues adjacent to the tumor, apparent mass invading the chest wall, and rib destruction. The CT scans were classified as positive, negative, or equivocal for invasion, and a decision matrix was constructed comparing CT results with pathologic data. CT scanning has low accuracy in assessing chest wall invasion in patients with peripheral lung cancers.

  12. Ozone contactor hydraulic considerations in meeting CT disinfection...

    Office of Scientific and Technical Information (OSTI)

    Optimization of ozone dose and contact time for CT calculations was performed in the pilot ... Resource Relation: Journal Name: Ozone: Science and Engineering (The Journal of the ...

  13. SU-E-T-70: Commissioning a Multislice CT Scanner for X-Ray CT Polymer Gel Dosimetry

    SciTech Connect (OSTI)

    Johnston, H; Hilts, M; Jirasek, A

    2014-06-01

    Purpose: To commission a multislice computed tomography (CT) scanner for fast and reliable readout of radiation therapy (RT) dose distributions using CT polymer gel dosimetry (PGD). Methods: Commissioning was performed for a 16-slice CT scanner using images acquired through a 1L cylinder filled with water. Additional images were collected using a single slice machine for comparison purposes. The variability in CT number associated with the anode heel effect was evaluated and used to define a new slice-by-slice background image subtraction technique. Image quality was assessed for the multislice system by comparing image noise and uniformity to that of the single slice machine. The consistency in CT number across slices acquired simultaneously using the multislice detector array was also evaluated. Finally, the variability in CT number due to increasing x-ray tube load was measured for the multislice scanner and compared to the tube load effects observed on the single slice machine. Results: Slice-by-slice background subtraction effectively removes the variability in CT number across images acquired simultaneously using the multislice scanner and is the recommended background subtraction method when using a multislice CT system. Image quality for the multislice machine was found to be comparable to that of the single slice scanner. Further study showed CT number was consistent across image slices acquired simultaneously using the multislice detector array for each detector configuration of the slice thickness examined. In addition, the multislice system was found to eliminate variations in CT number due to increasing x-ray tube load and reduce scanning time by a factor of 4 when compared to imaging a large volume using a single slice scanner. Conclusion: A multislice CT scanner has been commissioning for CT PGD, allowing images of an entire dose distribution to be acquired in a matter of minutes. Funding support provided by the Natural Sciences and Engineering

  14. Explosive Detection in Aviation Applications Using CT

    SciTech Connect (OSTI)

    Martz, H E; Crawford, C R

    2011-02-15

    CT scanners are deployed world-wide to detect explosives in checked and carry-on baggage. Though very similar to single- and dual-energy multi-slice CT scanners used today in medical imaging, some recently developed explosives detection scanners employ multiple sources and detector arrays to eliminate mechanical rotation of a gantry, photon counting detectors for spectral imaging, and limited number of views to reduce cost. For each bag scanned, the resulting reconstructed images are first processed by automated threat recognition algorithms to screen for explosives and other threats. Human operators review the images only when these automated algorithms report the presence of possible threats. The US Department of Homeland Security (DHS) has requirements for future scanners that include dealing with a larger number of threats, higher probability of detection, lower false alarm rates and lower operating costs. One tactic that DHS is pursuing to achieve these requirements is to augment the capabilities of the established security vendors with third-party algorithm developers. A third-party in this context refers to academics and companies other than the established vendors. DHS is particularly interested in exploring the model that has been used very successfully by the medical imaging industry, in which university researchers develop algorithms that are eventually deployed in commercial medical imaging equipment. The purpose of this paper is to discuss opportunities for third-parties to develop advanced reconstruction and threat detection algorithms.

  15. American Ref-Fuel of SE CT Biomass Facility | Open Energy Information

    Open Energy Info (EERE)

    Ref-Fuel of SE CT Biomass Facility Jump to: navigation, search Name American Ref-Fuel of SE CT Biomass Facility Facility American Ref-Fuel of SE CT Sector Biomass Facility Type...

  16. MicroCT: Semi-Automated Analysis of CT Reconstructed Data of Home Made Explosive Materials Using the Matlab MicroCT Analysis GUI

    SciTech Connect (OSTI)

    Seetho, I M; Brown, W D; Kallman, J S; Martz, H E; White, W T

    2011-09-22

    This Standard Operating Procedure (SOP) provides the specific procedural steps for analyzing reconstructed CT images obtained under the IDD Standard Operating Procedures for data acquisition [1] and MicroCT image reconstruction [2], per the IDD Quality Assurance Plan for MicroCT Scanning [3]. Although intended to apply primarily to MicroCT data acquired in the HEAFCAT Facility at LLNL, these procedures may also be applied to data acquired at Tyndall from the YXLON cabinet and at TSL from the HEXCAT system. This SOP also provides the procedural steps for preparing the tables and graphs to be used in the reporting of analytical results. This SOP applies to R and D work - for production applications, use [4].

  17. MicroCT: Automated Analysis of CT Reconstructed Data of Home Made Explosive Materials Using the Matlab MicroCT Analysis GUI

    SciTech Connect (OSTI)

    Seetho, I M; Brown, W D; Kallman, J S; Martz, H E; White, W T

    2011-09-22

    This Standard Operating Procedure (SOP) provides the specific procedural steps for analyzing reconstructed CT images obtained under the IDD Standard Operating Procedures for data acquisition [1] and MicroCT image reconstruction [2], per the IDD Quality Assurance Plan for MicroCT Scanning [3]. Although intended to apply primarily to MicroCT data acquired in the HEAFCAT Facility at LLNL, these procedures may also be applied to data acquired at Tyndall from the YXLON cabinet and at TSL from the HEXCAT system. This SOP also provides the procedural steps for preparing the tables and graphs to be used in the reporting of analytical results. This SOP applies to production work - for R and D there are two other semi-automated methods as given in [4, 5].

  18. DOE - Office of Legacy Management -- American Chain and Cable Co - CT 15

    Office of Legacy Management (LM)

    Chain and Cable Co - CT 15 FUSRAP Considered Sites Site: American Chain and Cable Co (CT.15 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Bridgeport , Connecticut CT.15-1 Evaluation Year: 1987 CT.15-1 Site Operations: Research and development involving uranium metal reclamation. CT.15-1 CT.15-2 Site Disposition: Eliminated - Potential for contamination considered remote based on the limited quantity of materials and short duration of

  19. DOE - Office of Legacy Management -- New England Lime Co - CT 10

    Office of Legacy Management (LM)

    England Lime Co - CT 10 FUSRAP Considered Sites Site: NEW ENGLAND LIME CO. (CT.10) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: NELCO (Magnesium Division) CT.10-1 Location: Canaan , Connecticut CT.10-2 Evaluation Year: 1987 CT.10-1 Site Operations: AEC source for magnesium and calcium. Conducted limited tests to evaluate potential for recovery of magnesium from uranium residues. CT.10-2 Site Disposition: Eliminated - Potential for contamination

  20. DOE - Office of Legacy Management -- Yale Heavy Ion Linear Accelerator - CT

    Office of Legacy Management (LM)

    05 Yale Heavy Ion Linear Accelerator - CT 05 FUSRAP Considered Sites Site: Yale Heavy Ion Linear Accelerator (CT.05) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: New Haven , Connecticut CT.05-1 Evaluation Year: 1987 CT.05-3 Site Operations: Research and development with solvents. CT.05-1 Site Disposition: Eliminated - Potential for contamination remote based on limited amount of materials handled CT.05-3 Radioactive Materials

  1. AAPG bulletin. Volume 73

    SciTech Connect (OSTI)

    Not Available

    1989-03-01

    Abstracts of papers given at a conference dealing with petroleum and natural gas geology, exploration, and production is presented. Each abstract was indexed for the U.S. Department of Energy's Energy Data Base.

  2. JC3 Bulletin Archive

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    div>

    Sat, 31 Aug 2013 08:00:00 +0000 717026 at http:energy.gov V-231: Cisco Identity Services Engine Discloses Authentication Credentials to Remote Users http:...

  3. Spectra of clinical CT scanners using a portable Compton spectrometer

    SciTech Connect (OSTI)

    Duisterwinkel, H. A.; Abbema, J. K. van; Kawachimaru, R.; Paganini, L.; Graaf, E. R. van der; Brandenburg, S.; Goethem, M. J. van

    2015-04-15

    Purpose: Spectral information of the output of x-ray tubes in (dual source) computer tomography (CT) scanners can be used to improve the conversion of CT numbers to proton stopping power and can be used to advantage in CT scanner quality assurance. The purpose of this study is to design, validate, and apply a compact portable Compton spectrometer that was constructed to accurately measure x-ray spectra of CT scanners. Methods: In the design of the Compton spectrometer, the shielding materials were carefully chosen and positioned to reduce background by x-ray fluorescence from the materials used. The spectrum of Compton scattered x-rays alters from the original source spectrum due to various physical processes. Reconstruction of the original x-ray spectrum from the Compton scattered spectrum is based on Monte Carlo simulations of the processes involved. This reconstruction is validated by comparing directly and indirectly measured spectra of a mobile x-ray tube. The Compton spectrometer is assessed in a clinical setting by measuring x-ray spectra at various tube voltages of three different medical CT scanner x-ray tubes. Results: The directly and indirectly measured spectra are in good agreement (their ratio being 0.99) thereby validating the reconstruction method. The measured spectra of the medical CT scanners are consistent with theoretical spectra and spectra obtained from the x-ray tube manufacturer. Conclusions: A Compton spectrometer has been successfully designed, constructed, validated, and applied in the measurement of x-ray spectra of CT scanners. These measurements show that our compact Compton spectrometer can be rapidly set-up using the alignment lasers of the CT scanner, thereby enabling its use in commissioning, troubleshooting, and, e.g., annual performance check-ups of CT scanners.

  4. Cholesterol granuloma of the petrous apex: CT diagnosis

    SciTech Connect (OSTI)

    Lo, W.W.M.; Solti-Bohman, L.G.; Brackmann, D.E.; Gruskin, P.

    1984-12-01

    Cholesterol granuloma of the petrous apex is a readily recognizable and treatable entity that is more common than previously realized. Cholesterol granuloma grows slowly in the petrous apex as a mass lesion until it produces hearing loss, tinnitus, vertigo, and facial twitching. Twelve cases of cholesterol granuloma of the petrous apex are illustrated; ten of these analyzed in detail, especially with respect to CT findings. A sharply and smoothly marginated expansile lesion in the petrous apex, isodense with plain and nonenhancing on CT, is in all probability a cholesterol granuloma. Preoperative recognition by CT is important for planning proper treatment.

  5. BAIC CT T SK Holdings JV | Open Energy Information

    Open Energy Info (EERE)

    JV Place: Beijing Municipality, China Product: China-based JV to manufacture and sell electric cars. References: BAIC, CT&T & SK Holdings JV1 This article is a stub. You can...

  6. DOE - Office of Legacy Management -- Fenn Machinery Co - CT 11

    Office of Legacy Management (LM)

    Mayor R. Mortemsem; Subject: Information regarding Fenn Mfg. Site; December 2, 1994 CT.11-3 - US AEC Letter; R. Smith to D. Sturges; Subject: Uranium Fabrication; November 8, 195

  7. CT Scan of Earth Links Mantle Plumes with Volcanic Hotspots

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    CT Scan of Earth Links Mantle Plumes with Volcanic Hotspots CT Scan of Earth Links Mantle Plumes with Volcanic Hotspots Simulations Run at NERSC Show How Seismic Waves Travel Through Mantle September 2, 2015 Robert Sanders, rlsanders@berkeley.edu, (510) 643-6998 NERSC PI: Barbara Romanowicz Lead Institution: University of California, Berkeley Project Title: Imaging and Calibration of Mantle Structure at Global and Regional Scales Using Full-Waveform Seismic Tomography NERSC Resources Used:

  8. TH-C-BRD-06: A Novel MRI Based CT Artifact Correction Method for Improving Proton Range Calculation in the Presence of Severe CT Artifacts

    SciTech Connect (OSTI)

    Park, P; Schreibmann, E; Fox, T; Roper, J; Elder, E; Tejani, M; Crocker, I; Curran, W; Dhabaan, A

    2014-06-15

    Purpose: Severe CT artifacts can impair our ability to accurately calculate proton range thereby resulting in a clinically unacceptable treatment plan. In this work, we investigated a novel CT artifact correction method based on a coregistered MRI and investigated its ability to estimate CT HU and proton range in the presence of severe CT artifacts. Methods: The proposed method corrects corrupted CT data using a coregistered MRI to guide the mapping of CT values from a nearby artifact-free region. First patient MRI and CT images were registered using 3D deformable image registration software based on B-spline and mutual information. The CT slice with severe artifacts was selected as well as a nearby slice free of artifacts (e.g. 1cm away from the artifact). The two sets of paired MRI and CT images at different slice locations were further registered by applying 2D deformable image registration. Based on the artifact free paired MRI and CT images, a comprehensive geospatial analysis was performed to predict the correct CT HU of the CT image with severe artifact. For a proof of concept, a known artifact was introduced that changed the ground truth CT HU value up to 30% and up to 5cm error in proton range. The ability of the proposed method to recover the ground truth was quantified using a selected head and neck case. Results: A significant improvement in image quality was observed visually. Our proof of concept study showed that 90% of area that had 30% errors in CT HU was corrected to 3% of its ground truth value. Furthermore, the maximum proton range error up to 5cm was reduced to 4mm error. Conclusion: MRI based CT artifact correction method can improve CT image quality and proton range calculation for patients with severe CT artifacts.

  9. DOE - Office of Legacy Management -- Metals Selling Corp - CT 0-01

    Office of Legacy Management (LM)

    Selling Corp - CT 0-01 FUSRAP Considered Sites Site: METALS SELLING CORP. (CT.0-01 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Putnam , Connecticut CT.0-01-1 Evaluation Year: 1986 CT.0-01-1 Site Operations: Performed grinding of (non-radioactive) magnesium circa 1950 -1952 as a sub-contractor to Mallinckrodt Corp. CT.0-01-1 Site Disposition: Eliminated - No indication that radioactive materials were handled at this location

  10. CT reconstruction techniques for improved accuracy of lung CT airway measurement

    SciTech Connect (OSTI)

    Rodriguez, A.; Ranallo, F. N.; Judy, P. F.; Gierada, D. S.; Fain, S. B.

    2014-11-01

    Purpose: To determine the impact of constrained reconstruction techniques on quantitative CT (qCT) of the lung parenchyma and airways for low x-ray radiation dose. Methods: Measurement of small airways with qCT remains a challenge, especially for low x-ray dose protocols. Images of the COPDGene quality assurance phantom (CTP698, The Phantom Laboratory, Salem, NY) were obtained using a GE discovery CT750 HD scanner for helical scans at x-ray radiation dose-equivalents ranging from 1 to 4.12 mSv (12100 mA s currenttime product). Other parameters were 40 mm collimation, 0.984 pitch, 0.5 s rotation, and 0.625 mm thickness. The phantom was sandwiched between 7.5 cm thick water attenuating phantoms for a total length of 20 cm to better simulate the scatter conditions of patient scans. Image data sets were reconstructed using STANDARD (STD), DETAIL, BONE, and EDGE algorithms for filtered back projection (FBP), 100% adaptive statistical iterative reconstruction (ASIR), and Veo reconstructions. Reduced (half) display field of view (DFOV) was used to increase sampling across airway phantom structures. Inner diameter (ID), wall area percent (WA%), and wall thickness (WT) measurements of eight airway mimicking tubes in the phantom, including a 2.5 mm ID (42.6 WA%, 0.4 mm WT), 3 mm ID (49.0 WA%, 0.6 mm WT), and 6 mm ID (49.0 WA%, 1.2 mm WT) were performed with Airway Inspector (Surgical Planning Laboratory, Brigham and Womens Hospital, Boston, MA) using the phase congruency edge detection method. The average of individual measures at five central slices of the phantom was taken to reduce measurement error. Results: WA% measures were greatly overestimated while IDs were underestimated for the smaller airways, especially for reconstructions at full DFOV (36 cm) using the STD kernel, due to poor sampling and spatial resolution (0.7 mm pixel size). Despite low radiation dose, the ID of the 6 mm ID airway was consistently measured accurately for all methods other than STD FBP

  11. Characterization of the nanoDot OSLD dosimeter in CT

    SciTech Connect (OSTI)

    Scarboro, Sarah B.; Cody, Dianna; Followill, David; Court, Laurence; Stingo, Francesco C.; Kry, Stephen F.; Alvarez, Paola; Zhang, Di; McNitt-Gray, Michael

    2015-04-15

    Purpose: The extensive use of computed tomography (CT) in diagnostic procedures is accompanied by a growing need for more accurate and patient-specific dosimetry techniques. Optically stimulated luminescent dosimeters (OSLDs) offer a potential solution for patient-specific CT point-based surface dosimetry by measuring air kerma. The purpose of this work was to characterize the OSLD nanoDot for CT dosimetry, quantifying necessary correction factors, and evaluating the uncertainty of these factors. Methods: A characterization of the Landauer OSL nanoDot (Landauer, Inc., Greenwood, IL) was conducted using both measurements and theoretical approaches in a CT environment. The effects of signal depletion, signal fading, dose linearity, and angular dependence were characterized through direct measurement for CT energies (80–140 kV) and delivered doses ranging from ∼5 to >1000 mGy. Energy dependence as a function of scan parameters was evaluated using two independent approaches: direct measurement and a theoretical approach based on Burlin cavity theory and Monte Carlo simulated spectra. This beam-quality dependence was evaluated for a range of CT scanning parameters. Results: Correction factors for the dosimeter response in terms of signal fading, dose linearity, and angular dependence were found to be small for most measurement conditions (<3%). The relative uncertainty was determined for each factor and reported at the two-sigma level. Differences in irradiation geometry (rotational versus static) resulted in a difference in dosimeter signal of 3% on average. Beam quality varied with scan parameters and necessitated the largest correction factor, ranging from 0.80 to 1.15 relative to a calibration performed in air using a 120 kV beam. Good agreement was found between the theoretical and measurement approaches. Conclusions: Correction factors for the measurement of air kerma were generally small for CT dosimetry, although angular effects, and particularly effects due

  12. A comparison of MR and CT in suspected sacroiliitis

    SciTech Connect (OSTI)

    Wittram, C.; Whitehouse, G.H.; Williams, J.W.; Bucknall, R.C.

    1996-01-01

    A prospective study to compare the MR and CT images of patients with suspected sacroilitis and to establish the optimal MR sequences to demonstrate the changes of sacroilitis was conducted. Thirty-nine patients and nine controls were imaged in the axial plane, with SE T1-, T2-weighted fast spin echo (T2), T1 with fat suppression (T1WFS), and fast short T inversion recovery (fast STIR) sequences on a 1.5 T system. The sacroiliac joints of all patients were imaged with CT. The images were evaluated by two independent radiologists. Following the blinded reading, direct comparison of T1 and T1WFS, T2, and fast STIR of the CT positive group was made to determine the optimal MR sequences. The sensitivity and specificity of MR images for the detection of cortical erosions and subchondral sclerosis when compared to CT images were 100 and 94.3%, respectively; interobserver variation was low (k = 0.80). T1WFS and fast STIR images were superior to-T1 and T2 images, respectively, in demonstrating the changes of sacroilitis. MRI (T1WFS and fast STIR) can replace CT in cases with a strong clinical suspicion of sacroilitis and equivocal or normal plain radiographs. 25 refs., 3 figs., 2 tabs.

  13. Realistic simulation of reduced-dose CT with noise modeling and sinogram synthesis using DICOM CT images

    SciTech Connect (OSTI)

    Won Kim, Chang; Kim, Jong Hyo

    2014-01-15

    Purpose: Reducing the patient dose while maintaining the diagnostic image quality during CT exams is the subject of a growing number of studies, in which simulations of reduced-dose CT with patient data have been used as an effective technique when exploring the potential of various dose reduction techniques. Difficulties in accessing raw sinogram data, however, have restricted the use of this technique to a limited number of institutions. Here, we present a novel reduced-dose CT simulation technique which provides realistic low-dose images without the requirement of raw sinogram data. Methods: Two key characteristics of CT systems, the noise equivalent quanta (NEQ) and the algorithmic modulation transfer function (MTF), were measured for various combinations of object attenuation and tube currents by analyzing the noise power spectrum (NPS) of CT images obtained with a set of phantoms. Those measurements were used to develop a comprehensive CT noise model covering the reduced x-ray photon flux, object attenuation, system noise, and bow-tie filter, which was then employed to generate a simulated noise sinogram for the reduced-dose condition with the use of a synthetic sinogram generated from a reference CT image. The simulated noise sinogram was filtered with the algorithmic MTF and back-projected to create a noise CT image, which was then added to the reference CT image, finally providing a simulated reduced-dose CT image. The simulation performance was evaluated in terms of the degree of NPS similarity, the noise magnitude, the bow-tie filter effect, and the streak noise pattern at photon starvation sites with the set of phantom images. Results: The simulation results showed good agreement with actual low-dose CT images in terms of their visual appearance and in a quantitative evaluation test. The magnitude and shape of the NPS curves of the simulated low-dose images agreed well with those of real low-dose images, showing discrepancies of less than +/?3.2% in

  14. PET/CT-guided Interventions: Personnel Radiation Dose

    SciTech Connect (OSTI)

    Ryan, E. Ronan Thornton, Raymond; Sofocleous, Constantinos T.; Erinjeri, Joseph P.; Hsu, Meier; Quinn, Brian; Dauer, Lawrence T.; Solomon, Stephen B.

    2013-08-01

    PurposeTo quantify radiation exposure to the primary operator and staff during PET/CT-guided interventional procedures.MethodsIn this prospective study, 12 patients underwent PET/CT-guided interventions over a 6 month period. Radiation exposure was measured for the primary operator, the radiology technologist, and the nurse anesthetist by means of optically stimulated luminescence dosimeters. Radiation exposure was correlated with the procedure time and the use of in-room image guidance (CT fluoroscopy or ultrasound).ResultsThe median effective dose was 0.02 (range 0-0.13) mSv for the primary operator, 0.01 (range 0-0.05) mSv for the nurse anesthetist, and 0.02 (range 0-0.05) mSv for the radiology technologist. The median extremity dose equivalent for the operator was 0.05 (range 0-0.62) mSv. Radiation exposure correlated with procedure duration and with the use of in-room image guidance. The median operator effective dose for the procedure was 0.015 mSv when conventional biopsy mode CT was used, compared to 0.06 mSv for in-room image guidance, although this did not achieve statistical significance as a result of the small sample size (p = 0.06).ConclusionThe operator dose from PET/CT-guided procedures is not significantly different than typical doses from fluoroscopically guided procedures. The major determinant of radiation exposure to the operator from PET/CT-guided interventional procedures is time spent in close proximity to the patient.

  15. Evolution of spatial resolution in breast CT at UC Davis

    SciTech Connect (OSTI)

    Gazi, Peymon M.; Yang, Kai; Burkett, George W.; Aminololama-Shakeri, Shadi; Anthony Seibert, J.; Boone, John M.

    2015-04-15

    Purpose: Dedicated breast computed tomography (bCT) technology for the purpose of breast cancer screening has been a focus of research at UC Davis since the late 1990s. Previous studies have shown that improvement in spatial resolution characteristics of this modality correlates with greater microcalcification detection, a factor considered a potential limitation of bCT. The aim of this study is to improve spatial resolution as characterized by the modulation transfer function (MTF) via changes in the scanner hardware components and operational schema. Methods: Four prototypes of pendant-geometry, cone-beam breast CT scanners were designed and developed spanning three generations of design evolution. To improve the system MTF in each bCT generation, modifications were made to the imaging components (x-ray tube and flat-panel detector), system geometry (source-to-isocenter and detector distance), and image acquisition parameters (technique factors, number of projections, system synchronization scheme, and gantry rotational speed). Results: Characterization of different generations of bCT systems shows these modifications resulted in a 188% improvement of the limiting MTF properties from the first to second generation and an additional 110% from the second to third. The intrinsic resolution degradation in the azimuthal direction observed in the first generation was corrected by changing the acquisition from continuous to pulsed x-ray acquisition. Utilizing a high resolution detector in the third generation, along with modifications made in system geometry and scan protocol, resulted in a 125% improvement in limiting resolution. An additional 39% improvement was obtained by changing the detector binning mode from 2 × 2 to 1 × 1. Conclusions: These results underscore the advancement in spatial resolution characteristics of breast CT technology. The combined use of a pulsed x-ray system, higher resolution flat-panel detector and changing the scanner geometry and image

  16. bectso-ct121 | netl.doe.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2 Demonstration of Innovative Applications of Technology for the CT-121 FGD Process - Project Brief [PDF-265KB] Southern Company Services, Newnan, GA PROGRAM PUBLICATIONS Final Reports Demonstration of Innovative Applications of Technology for the CT-121 FGD Process, Final Report (Jan 1997) Volume 1, Executive Summary [PDF-4.6MB] Volume 2, Operation [PDF-32.8MB] Volume 2 Appendices [PDF-6.3MB] Volume 3, Equipment Vol 3a, Materials and Maintenance [PDF-34.6MB] Vol 3b, Instrumentation and Control

  17. Can nontriggered thoracic CT be used for coronary artery calcium scoring? A phantom study

    SciTech Connect (OSTI)

    Xie, Xueqian; Greuter, Marcel J. W.; Groen, Jaap M.; Bock, Geertruida H. de; Oudkerk, Matthijs; Jong, Pim A. de; Vliegenthart, Rozemarijn

    2013-08-15

    Purpose: Coronary artery calcium score, traditionally based on electrocardiography (ECG)-triggered computed tomography (CT), predicts cardiovascular risk. However, nontriggered CT is extensively utilized. The study-purpose is to evaluate the in vitro agreement in coronary calcium score between nontriggered thoracic CT and ECG-triggered cardiac CT.Methods: Three artificial coronary arteries containing calcifications of different densities (high, medium, and low), and sizes (large, medium, and small), were studied in a moving cardiac phantom. Two 64-detector CT systems were used. The phantom moved at 0–90 mm/s in nontriggered low-dose CT as index test, and at 0–30 mm/s in ECG-triggered CT as reference. Differences in calcium scores between nontriggered and ECG-triggered CT were analyzed by t-test and 95% confidence interval. The sensitivity to detect calcification was calculated as the percentage of positive calcium scores.Results: Overall, calcium scores in nontriggered CT were not significantly different to those in ECG-triggered CT (p > 0.05). Calcium scores in nontriggered CT were within the 95% confidence interval of calcium scores in ECG-triggered CT, except predominantly at higher velocities (≥50 mm/s) for the high-density and large-size calcifications. The sensitivity for a nonzero calcium score was 100% for large calcifications, but 46%± 11% for small calcifications in nontriggered CT.Conclusions: When performing multiple measurements, good agreement in positive calcium scores is found between nontriggered thoracic and ECG-triggered cardiac CT. Agreement decreases with increasing coronary velocity. From this phantom study, it can be concluded that a high calcium score can be detected by nontriggered CT, and thus, that nontriggered CT likely can identify individuals at high risk of cardiovascular disease. On the other hand, a zero calcium score in nontriggered CT does not reliably exclude coronary calcification.

  18. Automatic CT simulation optimization for radiation therapy: A general strategy

    SciTech Connect (OSTI)

    Li, Hua Chen, Hsin-Chen; Tan, Jun; Gay, Hiram; Michalski, Jeff M.; Mutic, Sasa; Yu, Lifeng; Anastasio, Mark A.; Low, Daniel A.

    2014-03-15

    Purpose: In radiation therapy, x-ray computed tomography (CT) simulation protocol specifications should be driven by the treatment planning requirements in lieu of duplicating diagnostic CT screening protocols. The purpose of this study was to develop a general strategy that allows for automatically, prospectively, and objectively determining the optimal patient-specific CT simulation protocols based on radiation-therapy goals, namely, maintenance of contouring quality and integrity while minimizing patient CT simulation dose. Methods: The authors proposed a general prediction strategy that provides automatic optimal CT simulation protocol selection as a function of patient size and treatment planning task. The optimal protocol is the one that delivers the minimum dose required to provide a CT simulation scan that yields accurate contours. Accurate treatment plans depend on accurate contours in order to conform the dose to actual tumor and normal organ positions. An image quality index, defined to characterize how simulation scan quality affects contour delineation, was developed and used to benchmark the contouring accuracy and treatment plan quality within the predication strategy. A clinical workflow was developed to select the optimal CT simulation protocols incorporating patient size, target delineation, and radiation dose efficiency. An experimental study using an anthropomorphic pelvis phantom with added-bolus layers was used to demonstrate how the proposed prediction strategy could be implemented and how the optimal CT simulation protocols could be selected for prostate cancer patients based on patient size and treatment planning task. Clinical IMRT prostate treatment plans for seven CT scans with varied image quality indices were separately optimized and compared to verify the trace of target and organ dosimetry coverage. Results: Based on the phantom study, the optimal image quality index for accurate manual prostate contouring was 4.4. The optimal tube

  19. Percutaneous Bone Biopsies: Comparison between Flat-Panel Cone-Beam CT and CT-Scan Guidance

    SciTech Connect (OSTI)

    Tselikas, Lambros Joskin, Julien; Roquet, Florian; Farouil, Geoffroy; Dreuil, Serge; Hakimé, Antoine Teriitehau, Christophe; Auperin, Anne; Baere, Thierry de Deschamps, Frederic

    2015-02-15

    PurposeThis study was designed to compare the accuracy of targeting and the radiation dose of bone biopsies performed either under fluoroscopic guidance using a cone-beam CT with real-time 3D image fusion software (FP-CBCT-guidance) or under conventional computed tomography guidance (CT-guidance).MethodsSixty-eight consecutive patients with a bone lesion were prospectively included. The bone biopsies were scheduled under FP-CBCT-guidance or under CT-guidance according to operating room availability. Thirty-four patients underwent a bone biopsy under FP-CBCT and 34 under CT-guidance. We prospectively compared the two guidance modalities for their technical success, accuracy, puncture time, and pathological success rate. Patient and physician radiation doses also were compared.ResultsAll biopsies were technically successful, with both guidance modalities. Accuracy was significantly better using FP-CBCT-guidance (3 and 5 mm respectively: p = 0.003). There was no significant difference in puncture time (32 and 31 min respectively, p = 0.51) nor in pathological results (88 and 88 % of pathological success respectively, p = 1). Patient radiation doses were significantly lower with FP-CBCT (45 vs. 136 mSv, p < 0.0001). The percentage of operators who received a dose higher than 0.001 mSv (dosimeter detection dose threshold) was lower with FP-CBCT than CT-guidance (27 vs. 59 %, p = 0.01).ConclusionsFP-CBCT-guidance for bone biopsy is accurate and reduces patient and operator radiation doses compared with CT-guidance.

  20. Prostate CT segmentation method based on nonrigid registration in ultrasound-guided CT-based HDR prostate brachytherapy

    SciTech Connect (OSTI)

    Yang, Xiaofeng Rossi, Peter; Ogunleye, Tomi; Marcus, David M.; Jani, Ashesh B.; Curran, Walter J.; Liu, Tian; Mao, Hui

    2014-11-01

    Purpose: The technological advances in real-time ultrasound image guidance for high-dose-rate (HDR) prostate brachytherapy have placed this treatment modality at the forefront of innovation in cancer radiotherapy. Prostate HDR treatment often involves placing the HDR catheters (needles) into the prostate gland under the transrectal ultrasound (TRUS) guidance, then generating a radiation treatment plan based on CT prostate images, and subsequently delivering high dose of radiation through these catheters. The main challenge for this HDR procedure is to accurately segment the prostate volume in the CT images for the radiation treatment planning. In this study, the authors propose a novel approach that integrates the prostate volume from 3D TRUS images into the treatment planning CT images to provide an accurate prostate delineation for prostate HDR treatment. Methods: The authors approach requires acquisition of 3D TRUS prostate images in the operating room right after the HDR catheters are inserted, which takes 13 min. These TRUS images are used to create prostate contours. The HDR catheters are reconstructed from the intraoperative TRUS and postoperative CT images, and subsequently used as landmarks for the TRUSCT image fusion. After TRUSCT fusion, the TRUS-based prostate volume is deformed to the CT images for treatment planning. This method was first validated with a prostate-phantom study. In addition, a pilot study of ten patients undergoing HDR prostate brachytherapy was conducted to test its clinical feasibility. The accuracy of their approach was assessed through the locations of three implanted fiducial (gold) markers, as well as T2-weighted MR prostate images of patients. Results: For the phantom study, the target registration error (TRE) of gold-markers was 0.41 0.11 mm. For the ten patients, the TRE of gold markers was 1.18 0.26 mm; the prostate volume difference between the authors approach and the MRI-based volume was 7.28% 0.86%, and the

  1. Test of 3D CT reconstructions by EM + TV algorithm from undersampled data

    SciTech Connect (OSTI)

    Evseev, Ivan; Ahmann, Francielle; Silva, Hamilton P. da

    2013-05-06

    Computerized tomography (CT) plays an important role in medical imaging for diagnosis and therapy. However, CT imaging is connected with ionization radiation exposure of patients. Therefore, the dose reduction is an essential issue in CT. In 2011, the Expectation Maximization and Total Variation Based Model for CT Reconstruction (EM+TV) was proposed. This method can reconstruct a better image using less CT projections in comparison with the usual filtered back projection (FBP) technique. Thus, it could significantly reduce the overall dose of radiation in CT. This work reports the results of an independent numerical simulation for cone beam CT geometry with alternative virtual phantoms. As in the original report, the 3D CT images of 128 Multiplication-Sign 128 Multiplication-Sign 128 virtual phantoms were reconstructed. It was not possible to implement phantoms with lager dimensions because of the slowness of code execution even by the CORE i7 CPU.

  2. Poster — Thur Eve — 06: Dose assessment of cone beam CT imaging protocols as part of SPECT/CT examinations

    SciTech Connect (OSTI)

    Tonkopi, E; Ross, AA

    2014-08-15

    Purpose: To assess radiation dose from the cone beam CT (CBCT) component of SPECT/CT studies and to compare with other CT examinations performed in our institution. Methods: We used an anthropomorphic chest phantom and the 6 cc ion chamber to measure entrance breast dose for several CBCT and diagnostic CT acquisition protocols. The CBCT effective dose was calculated with ImPACT software; the CT effective dose was evaluated from the DLP value and conversion factor, dependent on the anatomic region. The RADAR medical procedure radiation dose calculator was used to assess the nuclear medicine component of exam dose. Results: The entrance dose to the breast measured with the anthropomorphic phantom was 0.48 mGy and 9.41 mGy for cardiac and chest CBCT scans; and 4.59 mGy for diagnostic thoracic CT. The effective doses were 0.2 mSv, 3.2 mSv and 2.8 mSv respectively. For a small patient represented by the anthropomorphic phantom, the dose from the diagnostic CT was lower than from the CBCT scan, as a result of the exposure reduction options available on modern CT scanners. The CBCT protocols used the same fixed scanning techniques. The diagnostic CT dose based on the patient data was 35% higher than the phantom dose. For most SPECT/CT studies the dose from the CBCT component was comparable with the dose from the radiopharmaceutical. Conclusions: The patient radiation dose from the cone beam CT scan can be higher than that from a diagnostic CT and should be taken into consideration in evaluating total SPECT/CT patient dose.

  3. Non-medical Uses of Computed Tomography (CT) and Nuclear Magnetic Resonance

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (NMR) Non-medical Uses of Computed Tomography (CT) and Nuclear Magnetic Resonance (NMR) Resources with Additional Information Computed Tomography (CT) Scanner CT Scanner - Courtesy Stanford University Department of Energy Resources Engineering Computed tomography (CT) and Nuclear Magnetic Resonance (NMR) have been used to resolve industrial problems, for materials characterizations, and to provide non-destructive evaluations for discovering flaws in parts before their use, resulting in

  4. Automated planning of breast radiotherapy using cone beam CT imaging

    SciTech Connect (OSTI)

    Amit, Guy; Purdie, Thomas G.

    2015-02-15

    Purpose: Develop and clinically validate a methodology for using cone beam computed tomography (CBCT) imaging in an automated treatment planning framework for breast IMRT. Methods: A technique for intensity correction of CBCT images was developed and evaluated. The technique is based on histogram matching of CBCT image sets, using information from “similar” planning CT image sets from a database of paired CBCT and CT image sets (n = 38). Automated treatment plans were generated for a testing subset (n = 15) on the planning CT and the corrected CBCT. The plans generated on the corrected CBCT were compared to the CT-based plans in terms of beam parameters, dosimetric indices, and dose distributions. Results: The corrected CBCT images showed considerable similarity to their corresponding planning CTs (average mutual information 1.0±0.1, average sum of absolute differences 185 ± 38). The automated CBCT-based plans were clinically acceptable, as well as equivalent to the CT-based plans with average gantry angle difference of 0.99°±1.1°, target volume overlap index (Dice) of 0.89±0.04 although with slightly higher maximum target doses (4482±90 vs 4560±84, P < 0.05). Gamma index analysis (3%, 3 mm) showed that the CBCT-based plans had the same dose distribution as plans calculated with the same beams on the registered planning CTs (average gamma index 0.12±0.04, gamma <1 in 99.4%±0.3%). Conclusions: The proposed method demonstrates the potential for a clinically feasible and efficient online adaptive breast IMRT planning method based on CBCT imaging, integrating automation.

  5. DOE - Office of Legacy Management -- Olin Mathieson - CT 0-02

    Office of Legacy Management (LM)

    Olin Mathieson - CT 0-02 FUSRAP Considered Sites Site: OLIN MATHIESON (CT.0-02 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: United Nuclear Corporation CT.0-02-1 Location: New Haven , Connecticut CT.0-02-1 Evaluation Year: 1987 CT.0-02-1 Site Operations: Began fabrication of nuclear reactor fuel elements for AEC circa late-1950s. Later became part of a group forming United Nuclear Corp. and were then licensed by AEC. Performed work for U.S. Navy and

  6. A rapid noninvasive characterization of CT x-ray sources

    SciTech Connect (OSTI)

    Randazzo, Matt; Tambasco, Mauro

    2015-07-15

    Purpose: The aim of this study is to generate spatially varying half value layers (HVLs) that can be used to construct virtual equivalent source models of computed tomography (CT) x-ray sources for use in Monte Carlo CT dose computations. Methods: To measure the spatially varying HVLs, the authors combined a cylindrical HVL measurement technique with the characterization of bowtie filter relative attenuation (COBRA) geometry. An apparatus given the name “HVL Jig” was fabricated to accurately position a real-time dosimeter off-isocenter while surrounded by concentric cylindrical aluminum filters (CAFs). In this geometry, each projection of the rotating x-ray tube is filtered by an identical amount of high-purity (type 1100 H-14) aluminum while the stationary radiation dose probe records an air kerma rate versus time waveform. The CAFs were progressively nested to acquire exposure data at increasing filtrations to calculate the HVL. Using this dose waveform and known setup geometry, each timestamp was related to its corresponding fan angle. Data were acquired using axial CT protocols (i.e., rotating tube and stationary patient table) at energies of 80, 100, and 120 kVp on a single CT scanner. These measurements were validated against the more laborious conventional step-and-shoot approach (stationary x-ray tube). Results: At each energy, HVL data points from the COBRA-cylinder technique were fit to a trendline and compared with the conventional approach. The average relative difference in HVL between the two techniques was 1.3%. There was a systematic overestimation in HVL due to scatter contamination. Conclusions: The described method is a novel, rapid, accurate, and noninvasive approach that allows one to acquire the spatially varying fluence and HVL data using a single experimental setup in a minimum of three scans. These measurements can be used to characterize the CT beam in terms of the angle-dependent fluence and energy spectra along the bowtie filter

  7. Sci—Thur PM: Imaging — 06: Canada's National Computed Tomography (CT) Survey

    SciTech Connect (OSTI)

    Wardlaw, GM; Martel, N; Blackler, W; Asselin, J-F

    2014-08-15

    The value of computed tomography (CT) in medical imaging is reflected in its' increased use and availability since the early 1990's; however, given CT's relatively larger exposures (vs. planar x-ray) greater care must be taken to ensure that CT procedures are optimised in terms of providing the smallest dose possible while maintaining sufficient diagnostic image quality. The development of CT Diagnostic Reference Levels (DRLs) supports this process. DRLs have been suggested/supported by international/national bodies since the early 1990's and widely adopted elsewhere, but not on a national basis in Canada. Essentially, CT DRLs provide guidance on what is considered good practice for common CT exams, but require a representative sample of CT examination data to make any recommendations. Canada's National CT Survey project, in collaboration with provincial/territorial authorities, has collected a large national sample of CT practice data for 7 common examinations (with associated clinical indications) of both adult and pediatric patients. Following completion of data entry into a common database, a survey summary report and recommendations will be made on CT DRLs from this data. It is hoped that these can then be used by local regions to promote CT practice optimisation and support any dose reduction initiatives.

  8. In-patient to isocenter KERMA ratios in CT

    SciTech Connect (OSTI)

    Huda, Walter; Ogden, Kent M.; Lavallee, Robert L.; Roskopf, Marsha L.; Scalzetti, Ernest M.

    2011-10-15

    Purpose: To estimate in-patient KERMA for specific organs in computed tomography (CT) scanning using ratios to isocenter free-in-air KERMA obtained using a Rando phantom.Method: A CT scan of an anthropomorphic phantom results in an air KERMA K at a selected phantom location and air kerma K{sub CT} at the CT scanner isocenter when the scan is repeated in the absence of the phantom. The authors define the KERMA ratio (R{sub K}) as K/ K{sub CT}, which were experimentally determined in a Male Rando Phantom using lithium fluoride chips (TLD-100). R{sub K} values were obtained for a total of 400 individual point locations, as well as for 25 individual organs of interest in CT dosimetry. CT examinations of Rando were performed on a GE LightSpeed Ultra scanner operated at 80 kV, 120 kV, and 140 kV, as well as a Siemens Sensation 16 operated at 120 kV. Results: At 120 kV, median R{sub K} values for the GE and Siemens scanners were 0.60 and 0.64, respectively. The 10th percentile R{sub K} values ranged from 0.34 at 80 kV to 0.54 at 140 kV, and the 90th percentile R{sub K} values ranged from 0.64 at 80 kV to 0.78 at 140 kV. The average R{sub K} for the 25 Rando organs at 120 kV was 0.61 {+-} 0.08. Average R{sub K} values in the head, chest, and abdomen showed little variation. Relative to R{sub K} values in the head, chest, and abdomen obtained at 120 kV, R{sub K} values were about 12% lower in the pelvis and about 58% higher in the cervical spine region. Average R{sub K} values were about 6% higher on the Siemens Sensation 16 scanner than the GE LightSpeed Ultra. Reducing the x-ray tube voltage from 120 kV to 80 kV resulted in an average reduction in R{sub K} value of 34%, whereas increasing the x-ray tube voltage to 140 kV increased the average R{sub K} value by 9%. Conclusions: In-patient to isocenter relative KERMA values in Rando phantom can be used to estimate organ doses in similar sized adults undergoing CT examinations from easily measured air KERMA values at the

  9. TU-F-18A-09: CT Number Stability Across Patient Sizes Using Virtual-Monoenergetic Dual-Energy CT

    SciTech Connect (OSTI)

    Michalak, G; Grimes, J; Fletcher, J; McCollough, C; Halaweish, A

    2014-06-15

    Purpose: Virtual-monoenergetic imaging uses dual-energy CT data to synthesize images corresponding to a single photon energy, thereby reducing beam-hardening artifacts. This work evaluated the ability of a commercial virtual-monoenergetic algorithm to achieve stable CT numbers across patient sizes. Methods: Test objects containing a range of iodine and calcium hydroxyapatite concentrations were placed inside 8 torso-shaped water phantoms, ranging in lateral width from 15 to 50 cm, and scanned on a dual-source CT system (Siemens Somatom Force). Single-energy scans were acquired from 70-150 kV in 10 kV increments; dual-energy scans were acquired using 4 energy pairs (low energy: 70, 80, 90, and 100 kV; high energy: 150 kV + 0.6 mm Sn). CTDIvol was matched for all single- and dual-energy scans for a given phantom size. All scans used 128×0.6 mm collimation and were reconstructed with 1-mm thickness at 0.8-mm increment and a medium smooth body kernel. Monoenergetic images were generated using commercial software (syngo Via Dual Energy, VA30). Iodine contrast was calculated as the difference in mean iodine and water CT numbers from respective regions-of-interest in 10 consecutive images. Results: CT numbers remained stable as phantom width varied from 15 to 50 cm for all dual-energy data sets (except for at 50 cm using 70/150Sn due to photon starvation effects). Relative to the 15 cm phantom, iodine contrast was within 5.2% of the 70 keV value for phantom sizes up to 45 cm. At 90/150Sn, photon starvation did not occur at 50 cm, and iodine contrast in the 50-cm phantom was within 1.4% of the 15-cm phantom. Conclusion: Monoenergetic imaging, as implemented in the evaluated commercial system, eliminated the variation in CT numbers due to patient size, and may provide more accurate data for quantitative tasks, including radiation therapy treatment planning. Siemens Healthcare.

  10. Utilizing a simple CT dosimetry phantom for the comprehension of the operational characteristics of CT AEC systems

    SciTech Connect (OSTI)

    Tsalafoutas, Ioannis A.; Varsamidis, Athanasios; Thalassinou, Stella; Efstathopoulos, Efstathios P.

    2013-11-15

    Purpose: To investigate the utility of the nested polymethylacrylate (PMMA) phantom (which is available in many CT facilities for CTDI measurements), as a tool for the presentation and comparison of the ways that two different CT automatic exposure control (AEC) systems respond to a phantom when various scan parameters and AEC protocols are modified.Methods: By offsetting the two phantom's components (the head phantom and the body ring) half-way along their longitudinal axis, a phantom with three sections of different x-ray attenuation was created. Scan projection radiographs (SPRs) and helical scans of the three-section phantom were performed on a Toshiba Aquilion 64 and a Philips Brilliance 64 CT scanners, with different scan parameter selections [scan direction, pitch factor, slice thickness, and reconstruction interval (ST/RI), AEC protocol, and tube potential used for the SPRs]. The dose length product (DLP) values of each scan were recorded and the tube current (mA) values of the reconstructed CT images were plotted against the respective Z-axis positions on the phantom. Furthermore, measurements of the noise levels at the center of each phantom section were performed to assess the impact of mA modulation on image quality.Results: The mA modulation patterns of the two CT scanners were very dissimilar. The mA variations were more pronounced for Aquilion 64, where changes in any of the aforementioned scan parameters affected both the mA modulations curves and DLP values. However, the noise levels were affected only by changes in pitch, ST/RI, and AEC protocol selections. For Brilliance 64, changes in pitch affected the mA modulation curves but not the DLP values, whereas only AEC protocol and SPR tube potential selection variations affected both the mA modulation curves and DLP values. The noise levels increased for smaller ST/RI, larger weight category AEC protocol, and larger SPR tube potential selection.Conclusions: The nested PMMA dosimetry phantom can be

  11. ANL CT Reconstruction Algorithm for Utilizing Digital X-ray

    Energy Science and Technology Software Center (OSTI)

    2004-05-01

    Reconstructs X-ray computed tomographic images from large data sets known as 16-bit binary sinograms when using a massively parallelized computer architecture such as a Beowuif cluster by parallelizing the X-ray CT reconstruction routine. The algorithm uses the concept of generation of an image from carefully obtained multiple 1-D or 2-D X-ray projections. The individual projections are filtered using a digital Fast Fourier Transform. The literature refers to this as filtered back projection.

  12. Upright cone beam CT imaging using the onboard imager

    SciTech Connect (OSTI)

    Fave, Xenia Martin, Rachael; Yang, Jinzhong; Balter, Peter; Court, Laurence; Carvalho, Luis; Pan, Tinsu

    2014-06-15

    Purpose: Many patients could benefit from being treated in an upright position. The objectives of this study were to determine whether cone beam computed tomography (CBCT) could be used to acquire upright images for treatment planning and to demonstrate whether reconstruction of upright images maintained accurate geometry and Hounsfield units (HUs). Methods: A TrueBeam linac was programmed in developer mode to take upright CBCT images. The gantry head was positioned at 0°, and the couch was rotated to 270°. The x-ray source and detector arms were extended to their lateral positions. The x-ray source and gantry remained stationary as fluoroscopic projections were taken and the couch was rotated from 270° to 90°. The x-ray tube current was normalized to deposit the same dose (measured using a calibrated Farmer ion chamber) as that received during a clinical helical CT scan to the center of a cylindrical, polyethylene phantom. To extend the field of view, two couch rotation scans were taken with the detector offset 15 cm superiorly and then 15 cm inferiorly. The images from these two scans were stitched together before reconstruction. Upright reconstructions were compared to reconstructions from simulation CT scans of the same phantoms. Two methods were investigated for correcting the HUs, including direct calibration and mapping the values from a simulation CT. Results: Overall geometry, spatial linearity, and high contrast resolution were maintained in upright reconstructions. Some artifacts were created and HU accuracy was compromised; however, these limitations could be removed by mapping the HUs from a simulation CT to the upright reconstruction for treatment planning. Conclusions: The feasibility of using the TrueBeam linac to take upright CBCT images was demonstrated. This technique is straightforward to implement and could be of enormous benefit to patients with thoracic tumors or those who find a supine position difficult to endure.

  13. Oxygen transport properties estimation by DSMC-CT simulations

    SciTech Connect (OSTI)

    Bruno, Domenico; Frezzotti, Aldo; Ghiroldi, Gian Pietro

    2014-12-09

    Coupling DSMC simulations with classical trajectories calculations is emerging as a powerful tool to improve predictive capabilities of computational rarefied gas dynamics. The considerable increase of computational effort outlined in the early application of the method (Koura,1997) can be compensated by running simulations on massively parallel computers. In particular, GPU acceleration has been found quite effective in reducing computing time (Ferrigni,2012; Norman et al.,2013) of DSMC-CT simulations. The aim of the present work is to study rarefied Oxygen flows by modeling binary collisions through an accurate potential energy surface, obtained by molecular beams scattering (Aquilanti, et al.,1999). The accuracy of the method is assessed by calculating molecular Oxygen shear viscosity and heat conductivity following three different DSMC-CT simulation methods. In the first one, transport properties are obtained from DSMC-CT simulations of spontaneous fluctuation of an equilibrium state (Bruno et al, Phys. Fluids, 23, 093104, 2011). In the second method, the collision trajectory calculation is incorporated in a Monte Carlo integration procedure to evaluate the Taxman’s expressions for the transport properties of polyatomic gases (Taxman,1959). In the third, non-equilibrium zero and one-dimensional rarefied gas dynamic simulations are adopted and the transport properties are computed from the non-equilibrium fluxes of momentum and energy. The three methods provide close values of the transport properties, their estimated statistical error not exceeding 3%. The experimental values are slightly underestimated, the percentage deviation being, again, few percent.

  14. The relevance of MRI for patient modeling in head and neck hyperthermia treatment planning: A comparison of CT and CT-MRI based tissue segmentation on simulated temperature

    SciTech Connect (OSTI)

    Verhaart, René F. Paulides, Margarethus M.; Fortunati, Valerio; Walsum, Theo van; Veenland, Jifke F.; Lugt, Aad van der

    2014-12-15

    Purpose: In current clinical practice, head and neck (H and N) hyperthermia treatment planning (HTP) is solely based on computed tomography (CT) images. Magnetic resonance imaging (MRI) provides superior soft-tissue contrast over CT. The purpose of the authors’ study is to investigate the relevance of using MRI in addition to CT for patient modeling in H and N HTP. Methods: CT and MRI scans were acquired for 11 patients in an immobilization mask. Three observers manually segmented on CT, MRI T1 weighted (MRI-T1w), and MRI T2 weighted (MRI-T2w) images the following thermo-sensitive tissues: cerebrum, cerebellum, brainstem, myelum, sclera, lens, vitreous humor, and the optical nerve. For these tissues that are used for patient modeling in H and N HTP, the interobserver variation of manual tissue segmentation in CT and MRI was quantified with the mean surface distance (MSD). Next, the authors compared the impact of CT and CT and MRI based patient models on the predicted temperatures. For each tissue, the modality was selected that led to the lowest observer variation and inserted this in the combined CT and MRI based patient model (CT and MRI), after a deformable image registration. In addition, a patient model with a detailed segmentation of brain tissues (including white matter, gray matter, and cerebrospinal fluid) was created (CT and MRI{sub db}). To quantify the relevance of MRI based segmentation for H and N HTP, the authors compared the predicted maximum temperatures in the segmented tissues (T{sub max}) and the corresponding specific absorption rate (SAR) of the patient models based on (1) CT, (2) CT and MRI, and (3) CT and MRI{sub db}. Results: In MRI, a similar or reduced interobserver variation was found compared to CT (maximum of median MSD in CT: 0.93 mm, MRI-T1w: 0.72 mm, MRI-T2w: 0.66 mm). Only for the optical nerve the interobserver variation is significantly lower in CT compared to MRI (median MSD in CT: 0.58 mm, MRI-T1w: 1.27 mm, MRI-T2w: 1.40 mm

  15. Ultralow dose computed tomography attenuation correction for pediatric PET CT using adaptive statistical iterative reconstruction

    SciTech Connect (OSTI)

    Brady, Samuel L.; Shulkin, Barry L.

    2015-02-15

    Purpose: To develop ultralow dose computed tomography (CT) attenuation correction (CTAC) acquisition protocols for pediatric positron emission tomography CT (PET CT). Methods: A GE Discovery 690 PET CT hybrid scanner was used to investigate the change to quantitative PET and CT measurements when operated at ultralow doses (10–35 mA s). CT quantitation: noise, low-contrast resolution, and CT numbers for 11 tissue substitutes were analyzed in-phantom. CT quantitation was analyzed to a reduction of 90% volume computed tomography dose index (0.39/3.64; mGy) from baseline. To minimize noise infiltration, 100% adaptive statistical iterative reconstruction (ASiR) was used for CT reconstruction. PET images were reconstructed with the lower-dose CTAC iterations and analyzed for: maximum body weight standardized uptake value (SUV{sub bw}) of various diameter targets (range 8–37 mm), background uniformity, and spatial resolution. Radiation dose and CTAC noise magnitude were compared for 140 patient examinations (76 post-ASiR implementation) to determine relative dose reduction and noise control. Results: CT numbers were constant to within 10% from the nondose reduced CTAC image for 90% dose reduction. No change in SUV{sub bw}, background percent uniformity, or spatial resolution for PET images reconstructed with CTAC protocols was found down to 90% dose reduction. Patient population effective dose analysis demonstrated relative CTAC dose reductions between 62% and 86% (3.2/8.3–0.9/6.2). Noise magnitude in dose-reduced patient images increased but was not statistically different from predose-reduced patient images. Conclusions: Using ASiR allowed for aggressive reduction in CT dose with no change in PET reconstructed images while maintaining sufficient image quality for colocalization of hybrid CT anatomy and PET radioisotope uptake.

  16. Spectrotemporal CT data acquisition and reconstruction at low dose

    SciTech Connect (OSTI)

    Clark, Darin P.; Badea, Cristian T.; Lee, Chang-Lung; Kirsch, David G.

    2015-11-15

    Purpose: X-ray computed tomography (CT) is widely used, both clinically and preclinically, for fast, high-resolution anatomic imaging; however, compelling opportunities exist to expand its use in functional imaging applications. For instance, spectral information combined with nanoparticle contrast agents enables quantification of tissue perfusion levels, while temporal information details cardiac and respiratory dynamics. The authors propose and demonstrate a projection acquisition and reconstruction strategy for 5D CT (3D + dual energy + time) which recovers spectral and temporal information without substantially increasing radiation dose or sampling time relative to anatomic imaging protocols. Methods: The authors approach the 5D reconstruction problem within the framework of low-rank and sparse matrix decomposition. Unlike previous work on rank-sparsity constrained CT reconstruction, the authors establish an explicit rank-sparse signal model to describe the spectral and temporal dimensions. The spectral dimension is represented as a well-sampled time and energy averaged image plus regularly undersampled principal components describing the spectral contrast. The temporal dimension is represented as the same time and energy averaged reconstruction plus contiguous, spatially sparse, and irregularly sampled temporal contrast images. Using a nonlinear, image domain filtration approach, the authors refer to as rank-sparse kernel regression, the authors transfer image structure from the well-sampled time and energy averaged reconstruction to the spectral and temporal contrast images. This regularization strategy strictly constrains the reconstruction problem while approximately separating the temporal and spectral dimensions. Separability results in a highly compressed representation for the 5D data in which projections are shared between the temporal and spectral reconstruction subproblems, enabling substantial undersampling. The authors solved the 5D reconstruction

  17. Semiautomatic segmentation of liver metastases on volumetric CT images

    SciTech Connect (OSTI)

    Yan, Jiayong; Schwartz, Lawrence H.; Zhao, Binsheng

    2015-11-15

    Purpose: Accurate segmentation and quantification of liver metastases on CT images are critical to surgery/radiation treatment planning and therapy response assessment. To date, there are no reliable methods to perform such segmentation automatically. In this work, the authors present a method for semiautomatic delineation of liver metastases on contrast-enhanced volumetric CT images. Methods: The first step is to manually place a seed region-of-interest (ROI) in the lesion on an image. This ROI will (1) serve as an internal marker and (2) assist in automatically identifying an external marker. With these two markers, lesion contour on the image can be accurately delineated using traditional watershed transformation. Density information will then be extracted from the segmented 2D lesion and help determine the 3D connected object that is a candidate of the lesion volume. The authors have developed a robust strategy to automatically determine internal and external markers for marker-controlled watershed segmentation. By manually placing a seed region-of-interest in the lesion to be delineated on a reference image, the method can automatically determine dual threshold values to approximately separate the lesion from its surrounding structures and refine the thresholds from the segmented lesion for the accurate segmentation of the lesion volume. This method was applied to 69 liver metastases (1.1–10.3 cm in diameter) from a total of 15 patients. An independent radiologist manually delineated all lesions and the resultant lesion volumes served as the “gold standard” for validation of the method’s accuracy. Results: The algorithm received a median overlap, overestimation ratio, and underestimation ratio of 82.3%, 6.0%, and 11.5%, respectively, and a median average boundary distance of 1.2 mm. Conclusions: Preliminary results have shown that volumes of liver metastases on contrast-enhanced CT images can be accurately estimated by a semiautomatic segmentation

  18. Automated matching and segmentation of lymphoma on serial CT examinations

    SciTech Connect (OSTI)

    Yan Jiayong; Zhao Binsheng; Curran, Sean; Zelenetz, Andrew; Schwartz, Lawrence H.

    2007-01-15

    In patients with lymphoma, identification and quantification of the tumor extent on serial CT examinations is critical for assessing tumor response to therapy. In this paper, we present a computer method to automatically match and segment lymphomas in follow-up CT images. The method requires that target lymph nodes in baseline CT images be known. A fast, approximate alignment technique along the x, y, and axial directions is developed to provide a good initial condition for the subsequent fast free form deformation (FFD) registration of the baseline and the follow-up images. As a result of the registration, the deformed lymph node contours from the baseline images are used to automatically determine internal and external markers for the marker-controlled watershed segmentation performed in the follow-up images. We applied this automated registration and segmentation method retrospectively to 29 lymph nodes in 9 lymphoma patients treated in a clinical trial at our cancer center. A radiologist independently delineated all lymph nodes on all slices in the follow-up images and his manual contours served as the ''gold standard'' for evaluation of the method. Preliminary results showed that 26/29 (89.7%) lymph nodes were correctly matched; i.e., there was a geometrical overlap between the deformed lymph node from the baseline and its corresponding mass in the follow-up images. Of the matched 26 lymph nodes, 22 (84.6%) were successfully segmented; for these 22 lymph nodes, several metrics were calculated to quantify the method's performance. Among them, the average distance and the Hausdorff distance between the contours generated by the computer and those generated by the radiologist were 0.9 mm (stdev. 0.4 mm) and 3.9 mm (stdev. 2.1 mm), respectively.

  19. Semi-automatic delineation using weighted CT-MRI registered images...

    Office of Scientific and Technical Information (OSTI)

    cancer Citation Details In-Document Search Title: Semi-automatic delineation using weighted CT-MRI registered images for radiotherapy of nasopharyngeal cancer Purpose: ...

  20. Shear induced permeability test: Stripa Granite X-ray CT files and explanation

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Tim Kneafsey

    2014-01-21

    This folder contains X-ray CT images and an explanation related to the shear induced permeability testing of Stripa granite

  1. DOE Zero Energy Ready Home Case Study: BPC Green Builders, Danbury, CT |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy Danbury, CT DOE Zero Energy Ready Home Case Study: BPC Green Builders, Danbury, CT DOE Zero Energy Ready Home Case Study: BPC Green Builders, Danbury, CT Case study of a DOE Zero Energy Ready home in Danbury, CT, that scored HERS 35 without PV. This 2-story, 1,650-ft2 cabin built by a custom home builder for his own family meets Passive House Standards with 5.5-in. of foil-faced polysiocyanurate foam boards lining the outside walls, R-55 of rigid EPS foam under the slab,

  2. DOE Zero Energy Ready Home Case Study: Brookside Development, Derby, CT |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy Brookside Development, Derby, CT DOE Zero Energy Ready Home Case Study: Brookside Development, Derby, CT DOE Zero Energy Ready Home Case Study: Brookside Development, Derby, CT Case study of a DOE Zero Energy Ready home in Derby, CT, that achieves a HERS score of 45 without PV or HERS 26 with PV. The production home is one of a development of 7 two-story, 4,000+-ft2 certified homes that have 2x4 walls filled with 1.5 in. closed-cell spray foam, 2-in. fiberglass batt,

  3. CT Scans of Cores Metadata, Barrow, Alaska 2015

    SciTech Connect (OSTI)

    Katie McKnight; Tim Kneafsey; Craig Ulrich

    2015-03-11

    Individual ice cores were collected from Barrow Environmental Observatory in Barrow, Alaska, throughout 2013 and 2014. Cores were drilled along different transects to sample polygonal features (i.e. the trough, center and rim of high, transitional and low center polygons). Most cores were drilled around 1 meter in depth and a few deep cores were drilled around 3 meters in depth. Three-dimensional images of the frozen cores were constructed using a medical X-ray computed tomography (CT) scanner. TIFF files can be uploaded to ImageJ (an open-source imaging software) to examine soil structure and densities within each core.

  4. Simultaneous CT and SPECT tomography using CZT detectors

    DOE Patents [OSTI]

    Paulus, Michael J.; Sari-Sarraf, Hamed; Simpson, Michael L.; Britton, Jr., Charles L.

    2002-01-01

    A method for simultaneous transmission x-ray computed tomography (CT) and single photon emission tomography (SPECT) comprises the steps of: injecting a subject with a tracer compound tagged with a .gamma.-ray emitting nuclide; directing an x-ray source toward the subject; rotating the x-ray source around the subject; emitting x-rays during the rotating step; rotating a cadmium zinc telluride (CZT) two-sided detector on an opposite side of the subject from the source; simultaneously detecting the position and energy of each pulsed x-ray and each emitted .gamma.-ray captured by the CZT detector; recording data for each position and each energy of each the captured x-ray and .gamma.-ray; and, creating CT and SPECT images from the recorded data. The transmitted energy levels of the x-rays lower are biased lower than energy levels of the .gamma.-rays. The x-ray source is operated in a continuous mode. The method can be implemented at ambient temperatures.

  5. Quant-CT: Segmenting and Quantifying Computed Tomography

    Energy Science and Technology Software Center (OSTI)

    2011-10-01

    Quant-CT is currently a plugin to ImageJ, designed as a Java-class that provides control mechanism for the user to choose volumes of interest within porous material, followed by the selection of image subsamples for automated tuning of parameters for filters and classifiers, and finally measurement of material geometry, porosity, and visualization. Denoising is mandatory before any image interpretation, and we implemented a new 3D java code that performs bilateral filtering of data. Segmentation of themore » dense material is essential before any quantifications about geological sample structure, and we invented new schemes to deal with over segmentation when using statistical region merging algorithm to pull out grains that compose imaged material. It make uses of ImageJ API and other standard and thirty-party APIs. Quant-CT conception started in 2011 under Scidac-e sponsor, and details of the first prototype were documented in publications below. While it is used right now for microtomography images, it can potentially be used by anybody with 3D image data obtained by experiment or produced by simulation.« less

  6. Incorporating multislice imaging into x-ray CT polymer gel dosimetry

    SciTech Connect (OSTI)

    Johnston, H.; Hilts, M.; Jirasek, A.

    2015-04-15

    Purpose: To evaluate multislice computed tomography (CT) scanning for fast and reliable readout of radiation therapy (RT) dose distributions using CT polymer gel dosimetry (PGD) and to establish a baseline assessment of image noise and uniformity in an unirradiated gel dosimeter. Methods: A 16-slice CT scanner was used to acquire images through a 1 L cylinder filled with water. Additional images were collected using a single slice machine. The variability in CT number (N{sub CT}) associated with the anode heel effect was evaluated and used to define a new slice-by-slice background subtraction artifact removal technique for CT PGD. Image quality was assessed for the multislice system by evaluating image noise and uniformity. The agreement in N{sub CT} for slices acquired simultaneously using the multislice detector array was also examined. Further study was performed to assess the effects of increasing x-ray tube load on the constancy of measured N{sub CT} and overall scan time. In all cases, results were compared to the single slice machine. Finally, images were collected throughout the volume of an unirradiated gel dosimeter to quantify image noise and uniformity before radiation is delivered. Results: Slice-by-slice background subtraction effectively removes the variability in N{sub CT} observed across images acquired simultaneously using the multislice scanner and is the recommended background subtraction method when using a multislice CT system. Image noise was higher for the multislice system compared to the single slice scanner, but overall image quality was comparable between the two systems. Further study showed N{sub CT} was consistent across image slices acquired simultaneously using the multislice detector array for each detector configuration of the slice thicknesses examined. In addition, the multislice system was found to eliminate variations in N{sub CT} due to increasing x-ray tube load and reduce scanning time by a factor of 4 when compared to

  7. Lessons learned bulletin. Number 2

    SciTech Connect (OSTI)

    Not Available

    1994-05-01

    During the past four years, the Department of Energy -- Savannah River Operations Office and the Westinghouse Savannah River Company (WSRC) Environmental Restoration (ER) Program completed various activities ranging from waste site investigations to closure and post closure projects. Critiques for lessons learned regarding project activities are performed at the completion of each project milestone, and this critique interval allows for frequent recognition of lessons learned. In addition to project related lessons learned, ER also performs lessons learned critiques. T`he Savannah River Site (SRS) also obtains lessons learned information from general industry, commercial nuclear industry, naval nuclear programs, and other DOE sites within the complex. Procedures are approved to administer the lessons learned program, and a database is available to catalog applicable lessons learned regarding environmental remediation, restoration, and administrative activities. ER will continue to use this database as a source of information available to SRS personnel.

  8. Monthly Project Bulletin: September 2012

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    and NREL provide another level of quality assurance for home owners and industry, as well as support for our workforce in a career pathway with industry-recognized credentials. ...

  9. Monthly Project Bulletin: June 2012

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... Professional credentials demonstrate a degree of knowledge and skill. They show the individual cares enough about their profession to invest in training and verification of their ...

  10. Monthly Project Bulletin: April 2012

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... Learn more about the Guidelines for Home Energy Professionals project. Update your subscriptions, modify your password or e-mail address, or stop subscriptions at any time on your ...

  11. Monthly Project Bulletin: March 2012

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... for Electric & Gas Industries Association Update your subscriptions, modify your password or e-mail address, or stop subscriptions at any time on your Subscriber Preferences Page. ...

  12. SU-E-J-148: Tools for Development of 4D Proton CT

    SciTech Connect (OSTI)

    Dou, T; Ramos-Mendez, J; Piersimoni, P; Giacometti, V; Penfold, S; Censor, Y; Faddegon, B; Low, D; Schulte, R

    2015-06-15

    Purpose: To develop tools for performing 4D proton computed tomography (CT). Methods: A suitable patient with a tumor in the right lower lobe was selected from a set of 4D CT scans. The volumetric CT images formed the basis for calculating the parameters of a breathing model that allows reconstruction of a static reference CT and CT images in each breathing phase. The images were imported into the TOPAS Monte Carlo simulation platform for simulating an experimental proton CT scan with 45 projections spaced by 4 degree intervals. Each projection acquired data for 2 seconds followed by a gantry rotation for 2 seconds without acquisition. The scan covered 180 degrees with individual protons passing through a 9-cm slab of the patient’s lung covering the moving tumor. An initial proton energy sufficient for penetrating the patient from all directions was determined. Performing the proton CT simulation, TOPAS provided output of the proton energy and coordinates registered in two planes before and after the patient, respectively. The set of projection data was then used with an iterative reconstruction algorithm to generate a volumetric proton CT image set of the static reference image and the image obtained under breathing motion, respectively. Results: An initial proton energy of 230 MeV was found to be sufficient, while for an initial energy of 200 MeV a substantial number of protons did not penetrate the patient. The reconstruction of the static reference image set provided sufficient detail for treatment planning. Conclusion: We have developed tools to perform studies of proton CT in the presence of lung motion based on the TOPAS simulation toolkit. This will allow to optimize 4D reconstruction algorithms by synchronizing the acquired proton CT data with a breathing signal and utilizing a breathing model obtained prior to the proton CT scan. This research has been supported by the National Institute Of Biomedical Imaging And Bioengineering of the National

  13. TH-C-18A-08: A Management Tool for CT Dose Monitoring, Analysis, and Protocol Review

    SciTech Connect (OSTI)

    Wang, J; Chan, F; Newman, B; Larson, D; Leung, A; Fleischmann, D; Molvin, L; Marsh, D; Zorich, C; Phillips, L

    2014-06-15

    Purpose: To develop a customizable tool for enterprise-wide managing of CT protocols and analyzing radiation dose information of CT exams for a variety of quality control applications Methods: All clinical CT protocols implemented on the 11 CT scanners at our institution were extracted in digital format. The original protocols had been preset by our CT management team. A commercial CT dose tracking software (DoseWatch,GE healthcare,WI) was used to collect exam information (exam date, patient age etc.), scanning parameters, and radiation doses for all CT exams. We developed a Matlab-based program (MathWorks,MA) with graphic user interface which allows to analyze the scanning protocols with the actual dose estimates, and compare the data to national (ACR,AAPM) and internal reference values for CT quality control. Results: The CT protocol review portion of our tool allows the user to look up the scanning and image reconstruction parameters of any protocol on any of the installed CT systems among about 120 protocols per scanner. In the dose analysis tool, dose information of all CT exams (from 05/2013 to 02/2014) was stratified on a protocol level, and within a protocol down to series level, i.e. each individual exposure event. This allows numerical and graphical review of dose information of any combination of scanner models, protocols and series. The key functions of the tool include: statistics of CTDI, DLP and SSDE, dose monitoring using user-set CTDI/DLP/SSDE thresholds, look-up of any CT exam dose data, and CT protocol review. Conclusion: our inhouse CT management tool provides radiologists, technologists and administration a first-hand near real-time enterprise-wide knowledge on CT dose levels of different exam types. Medical physicists use this tool to manage CT protocols, compare and optimize dose levels across different scanner models. It provides technologists feedback on CT scanning operation, and knowledge on important dose baselines and thresholds.

  14. Five Years of Cyclotron Radioisotope Production Experiences at the First PET-CT in Venezuela

    SciTech Connect (OSTI)

    Colmenter, L.; Coelho, D.; Esteves, L. M.; Ruiz, N.; Morales, L.; Lugo, I.; Sajo-Bohus, L.; Liendo, J. A.; Greaves, E. D.; Barros, H.; Castillo, J.

    2007-10-26

    Five years operation of a compact cyclotron installed at PET-CT facility in Caracas, Venezuela is given. Production rate of {sup 18}F labeled FDG, operation and radiation monitoring experience are included. We conclude that {sup 18}FDG CT-PET is the most effective technique for patient diagnosis.

  15. Vision 20/20: Simultaneous CT-MRI — Next chapter of multimodality imaging

    SciTech Connect (OSTI)

    Wang, Ge Xi, Yan; Gjesteby, Lars; Getzin, Matthew; Yang, Qingsong; Cong, Wenxiang; Vannier, Michael

    2015-10-15

    Multimodality imaging systems such as positron emission tomography-computed tomography (PET-CT) and MRI-PET are widely available, but a simultaneous CT-MRI instrument has not been developed. Synergies between independent modalities, e.g., CT, MRI, and PET/SPECT can be realized with image registration, but such postprocessing suffers from registration errors that can be avoided with synchronized data acquisition. The clinical potential of simultaneous CT-MRI is significant, especially in cardiovascular and oncologic applications where studies of the vulnerable plaque, response to cancer therapy, and kinetic and dynamic mechanisms of targeted agents are limited by current imaging technologies. The rationale, feasibility, and realization of simultaneous CT-MRI are described in this perspective paper. The enabling technologies include interior tomography, unique gantry designs, open magnet and RF sequences, and source and detector adaptation. Based on the experience with PET-CT, PET-MRI, and MRI-LINAC instrumentation where hardware innovation and performance optimization were instrumental to construct commercial systems, the authors provide top-level concepts for simultaneous CT-MRI to meet clinical requirements and new challenges. Simultaneous CT-MRI fills a major gap of modality coupling and represents a key step toward the so-called “omnitomography” defined as the integration of all relevant imaging modalities for systems biology and precision medicine.

  16. Proton-induced x-ray fluorescence CT imaging

    SciTech Connect (OSTI)

    Bazalova-Carter, Magdalena Xing, Lei; Ahmad, Moiz; Matsuura, Taeko; Takao, Seishin; Shirato, Hiroki; Umegaki, Kikuo; Matsuo, Yuto; Fahrig, Rebecca

    2015-02-15

    Purpose: To demonstrate the feasibility of proton-induced x-ray fluorescence CT (pXFCT) imaging of gold in a small animal sized object by means of experiments and Monte Carlo (MC) simulations. Methods: First, proton-induced gold x-ray fluorescence (pXRF) was measured as a function of gold concentration. Vials of 2.2 cm in diameter filled with 0%–5% Au solutions were irradiated with a 220 MeV proton beam and x-ray fluorescence induced by the interaction of protons, and Au was detected with a 3 × 3 mm{sup 2} CdTe detector placed at 90° with respect to the incident proton beam at a distance of 45 cm from the vials. Second, a 7-cm diameter water phantom containing three 2.2-diameter vials with 3%–5% Au solutions was imaged with a 7-mm FWHM 220 MeV proton beam in a first generation CT scanning geometry. X-rays scattered perpendicular to the incident proton beam were acquired with the CdTe detector placed at 45 cm from the phantom positioned on a translation/rotation stage. Twenty one translational steps spaced by 3 mm at each of 36 projection angles spaced by 10° were acquired, and pXFCT images of the phantom were reconstructed with filtered back projection. A simplified geometry of the experimental data acquisition setup was modeled with the MC TOPAS code, and simulation results were compared to the experimental data. Results: A linear relationship between gold pXRF and gold concentration was observed in both experimental and MC simulation data (R{sup 2} > 0.99). All Au vials were apparent in the experimental and simulated pXFCT images. Specifically, the 3% Au vial was detectable in the experimental [contrast-to-noise ratio (CNR) = 5.8] and simulated (CNR = 11.5) pXFCT image. Due to fluorescence x-ray attenuation in the higher concentration vials, the 4% and 5% Au contrast were underestimated by 10% and 15%, respectively, in both the experimental and simulated pXFCT images. Conclusions: Proton-induced x-ray fluorescence CT imaging of 3%–5% gold solutions in a

  17. Cone-Beam Computed Tomography (CBCT) Versus CT in Lung Ablation Procedure: Which is Faster?

    SciTech Connect (OSTI)

    Cazzato, Roberto Luigi Battistuzzi, Jean-Benoit Catena, Vittorio; Grasso, Rosario Francesco Zobel, Bruno Beomonte; Schena, Emiliano; Buy, Xavier Palussiere, Jean

    2015-10-15

    AimTo compare cone-beam CT (CBCT) versus computed tomography (CT) guidance in terms of time needed to target and place the radiofrequency ablation (RFA) electrode on lung tumours.Materials and MethodsPatients at our institution who received CBCT- or CT-guided RFA for primary or metastatic lung tumours were retrospectively included. Time required to target and place the RFA electrode within the lesion was registered and compared across the two groups. Lesions were stratified into three groups according to their size (<10, 10–20, >20 mm). Occurrences of electrode repositioning, repositioning time, RFA complications, and local recurrence after RFA were also reported.ResultsForty tumours (22 under CT, 18 under CBCT guidance) were treated in 27 patients (19 male, 8 female, median age 67.25 ± 9.13 years). Thirty RFA sessions (16 under CBCT and 14 under CT guidance) were performed. Multivariable linear regression analysis showed that CBCT was faster than CT to target and place the electrode within the tumour independently from its size (β = −9.45, t = −3.09, p = 0.004). Electrode repositioning was required in 10/22 (45.4 %) tumours under CT guidance and 5/18 (27.8 %) tumours under CBCT guidance. Pneumothoraces occurred in 6/14 (42.8 %) sessions under CT guidance and in 6/16 (37.5 %) sessions under CBCT guidance. Two recurrences were noted for tumours receiving CBCT-guided RFA (2/17, 11.7 %) and three after CT-guided RFA (3/19, 15.8 %).ConclusionCBCT with live 3D needle guidance is a useful technique for percutaneous lung ablation. Despite lesion size, CBCT allows faster lung RFA than CT.

  18. Monitoring internal organ motion with continuous wave radar in CT

    SciTech Connect (OSTI)

    Pfanner, Florian; Maier, Joscha; Allmendinger, Thomas; Flohr, Thomas; Kachelrieß, Marc

    2013-09-15

    Purpose: To avoid motion artifacts in medical imaging or to minimize the exposure of healthy tissues in radiation therapy, medical devices are often synchronized with the patient's respiratory motion. Today's respiratory motion monitors require additional effort to prepare the patients, e.g., mounting a motion belt or placing an optical reflector on the patient's breast. Furthermore, they are not able to measure internal organ motion without implanting markers. An interesting alternative to assess the patient's organ motion is continuous wave radar. The aim of this work is to design, implement, and evaluate such a radar system focusing on application in CT.Methods: The authors designed a radar system operating in the 860 MHz band to monitor the patient motion. In the intended application of the radar system, the antennas are located close to the patient's body inside the table of a CT system. One receive and four transmitting antennas are used to avoid the requirement of exact patient positioning. The radar waves propagate into the patient's body and are reflected at tissue boundaries, for example at the borderline between muscle and adipose tissue, or at the boundaries of organs. At present, the authors focus on the detection of respiratory motion. The radar system consists of the hardware mentioned above as well as of dedicated signal processing software to extract the desired information from the radar signal. The system was evaluated using simulations and measurements. To simulate the radar system, a simulation model based on radar and wave field equations was designed and 4D respiratory-gated CT data sets were used as input. The simulated radar signals and the measured data were processed in the same way. The radar system hardware and the signal processing algorithms were tested with data from ten volunteers. As a reference, the respiratory motion signal was recorded using a breast belt simultaneously with the radar measurements.Results: Concerning the

  19. Investigation of statistical iterative reconstruction for dedicated breast CT

    SciTech Connect (OSTI)

    Makeev, Andrey; Glick, Stephen J.

    2013-08-15

    Purpose: Dedicated breast CT has great potential for improving the detection and diagnosis of breast cancer. Statistical iterative reconstruction (SIR) in dedicated breast CT is a promising alternative to traditional filtered backprojection (FBP). One of the difficulties in using SIR is the presence of free parameters in the algorithm that control the appearance of the resulting image. These parameters require tuning in order to achieve high quality reconstructions. In this study, the authors investigated the penalized maximum likelihood (PML) method with two commonly used types of roughness penalty functions: hyperbolic potential and anisotropic total variation (TV) norm. Reconstructed images were compared with images obtained using standard FBP. Optimal parameters for PML with the hyperbolic prior are reported for the task of detecting microcalcifications embedded in breast tissue.Methods: Computer simulations were used to acquire projections in a half-cone beam geometry. The modeled setup describes a realistic breast CT benchtop system, with an x-ray spectra produced by a point source and an a-Si, CsI:Tl flat-panel detector. A voxelized anthropomorphic breast phantom with 280 ?m microcalcification spheres embedded in it was used to model attenuation properties of the uncompressed woman's breast in a pendant position. The reconstruction of 3D images was performed using the separable paraboloidal surrogates algorithm with ordered subsets. Task performance was assessed with the ideal observer detectability index to determine optimal PML parameters.Results: The authors' findings suggest that there is a preferred range of values of the roughness penalty weight and the edge preservation threshold in the penalized objective function with the hyperbolic potential, which resulted in low noise images with high contrast microcalcifications preserved. In terms of numerical observer detectability index, the PML method with optimal parameters yielded substantially improved

  20. Segmentation-free empirical beam hardening correction for CT

    SciTech Connect (OSTI)

    Schller, Sren; Sawall, Stefan; Stannigel, Kai; Hlsbusch, Markus; Ulrici, Johannes; Hell, Erich; Kachelrie, Marc

    2015-02-15

    Purpose: The polychromatic nature of the x-ray beams and their effects on the reconstructed image are often disregarded during standard image reconstruction. This leads to cupping and beam hardening artifacts inside the reconstructed volume. To correct for a general cupping, methods like water precorrection exist. They correct the hardening of the spectrum during the penetration of the measured object only for the major tissue class. In contrast, more complex artifacts like streaks between dense objects need other techniques of correction. If using only the information of one single energy scan, there are two types of corrections. The first one is a physical approach. Thereby, artifacts can be reproduced and corrected within the original reconstruction by using assumptions in a polychromatic forward projector. These assumptions could be the used spectrum, the detector response, the physical attenuation and scatter properties of the intersected materials. A second method is an empirical approach, which does not rely on much prior knowledge. This so-called empirical beam hardening correction (EBHC) and the previously mentioned physical-based technique are both relying on a segmentation of the present tissues inside the patient. The difficulty thereby is that beam hardening by itself, scatter, and other effects, which diminish the image quality also disturb the correct tissue classification and thereby reduce the accuracy of the two known classes of correction techniques. The herein proposed method works similar to the empirical beam hardening correction but does not require a tissue segmentation and therefore shows improvements on image data, which are highly degraded by noise and artifacts. Furthermore, the new algorithm is designed in a way that no additional calibration or parameter fitting is needed. Methods: To overcome the segmentation of tissues, the authors propose a histogram deformation of their primary reconstructed CT image. This step is essential for the

  1. SU-E-J-43: Deformed Planning CT as An Electron Density Substitute for Cone-Beam CT

    SciTech Connect (OSTI)

    Mishra, K; Godley, A

    2014-06-01

    Purpose: To confirm that deforming the planning CT to the daily Cone-Beam CTs (CBCT) can provide suitable electron density for adaptive planning. We quantify the dosimetric difference between plans calculated on deformed planning CTs (DPCT) and daily CT-on-rails images (CTOR). CTOR is used as a test of the method as CTOR already contains accurate electron density to compare against. Methods: Five prostate only IMRT patients, each with five CTOR images, were selected and re-planned on Panther (Prowess Inc.) with a uniform 5 mm PTV expansion, prescribed 78 Gy. The planning CT was deformed to match each CTOR using ABAS (Elekta Inc.). Contours were drawn on the CTOR, and copied to the DPCT. The original treatment plan was copied to both the CTOR and DPCT, keeping the center of the prostate as the isocenter. The plans were then calculated using the collapsed cone heterogeneous dose engine of Prowess and typical DVH planning parameters used to compare them. Results: Each DPCT was visually compared to its CTOR with no differences observed. The agreement of the copied CTOR contours with the DPCT anatomy further demonstrated the deformation accuracy. The plans calculated using CTOR and DPCT were compared. Over the 25 plan pairs, the average difference between them for prostate D100, D98 and D95 were 0.5%, 0.2%, and 0.2%; PTV D98, D95 and mean dose: 0.3%, 0.2% and 0.3%; bladder V70, V60 and mean dose: 1.1%, 0.7%, and 0.2%; and rectum mean dose: 0.3%. (D100 is the dose covering 100% of the target; V70 is the volume of the organ receiving 70 Gy). Conclusion: We observe negligible difference between the dose calculated on the DPCT and the CTOR, implying that deformed planning CTs are a suitable substitute for electron density. The method can now be applied to CBCTs. Research version of Panther provided by Prowess Inc. Research version of ABAS provided by Elekta Inc.

  2. Patient dose estimation from CT scans at the Mexican National Neurology and Neurosurgery Institute

    SciTech Connect (OSTI)

    Alva-Sánchez, Héctor

    2014-11-07

    In the radiology department of the Mexican National Institute of Neurology and Neurosurgery, a dedicated institute in Mexico City, on average 19.3 computed tomography (CT) examinations are performed daily on hospitalized patients for neurological disease diagnosis, control scans and follow-up imaging. The purpose of this work was to estimate the effective dose received by hospitalized patients who underwent a diagnostic CT scan using typical effective dose values for all CT types and to obtain the estimated effective dose distributions received by surgical and non-surgical patients. Effective patient doses were estimated from values per study type reported in the applications guide provided by the scanner manufacturer. This retrospective study included all hospitalized patients who underwent a diagnostic CT scan between 1 January 2011 and 31 December 2012. A total of 8777 CT scans were performed in this two-year period. Simple brain scan was the CT type performed the most (74.3%) followed by contrasted brain scan (6.1%) and head angiotomography (5.7%). The average number of CT scans per patient was 2.83; the average effective dose per patient was 7.9 mSv; the mean estimated radiation dose was significantly higher for surgical (9.1 mSv) than non-surgical patients (6.0 mSv). Three percent of the patients had 10 or more brain CT scans and exceeded the organ radiation dose threshold set by the International Commission on Radiological Protection for deterministic effects of the eye-lens. Although radiation patient doses from CT scans were in general relatively low, 187 patients received a high effective dose (>20 mSv) and 3% might develop cataract from cumulative doses to the eye lens.

  3. Deformable image registration based automatic CT-to-CT contour propagation for head and neck adaptive radiotherapy in the routine clinical setting

    SciTech Connect (OSTI)

    Kumarasiri, Akila Siddiqui, Farzan; Liu, Chang; Yechieli, Raphael; Shah, Mira; Pradhan, Deepak; Zhong, Hualiang; Chetty, Indrin J.; Kim, Jinkoo

    2014-12-15

    Purpose: To evaluate the clinical potential of deformable image registration (DIR)-based automatic propagation of physician-drawn contours from a planning CT to midtreatment CT images for head and neck (H and N) adaptive radiotherapy. Methods: Ten H and N patients, each with a planning CT (CT1) and a subsequent CT (CT2) taken approximately 3–4 week into treatment, were considered retrospectively. Clinically relevant organs and targets were manually delineated by a radiation oncologist on both sets of images. Four commercial DIR algorithms, two B-spline-based and two Demons-based, were used to deform CT1 and the relevant contour sets onto corresponding CT2 images. Agreement of the propagated contours with manually drawn contours on CT2 was visually rated by four radiation oncologists in a scale from 1 to 5, the volume overlap was quantified using Dice coefficients, and a distance analysis was done using center of mass (CoM) displacements and Hausdorff distances (HDs). Performance of these four commercial algorithms was validated using a parameter-optimized Elastix DIR algorithm. Results: All algorithms attained Dice coefficients of >0.85 for organs with clear boundaries and those with volumes >9 cm{sup 3}. Organs with volumes <3 cm{sup 3} and/or those with poorly defined boundaries showed Dice coefficients of ∼0.5–0.6. For the propagation of small organs (<3 cm{sup 3}), the B-spline-based algorithms showed higher mean Dice values (Dice = 0.60) than the Demons-based algorithms (Dice = 0.54). For the gross and planning target volumes, the respective mean Dice coefficients were 0.8 and 0.9. There was no statistically significant difference in the Dice coefficients, CoM, or HD among investigated DIR algorithms. The mean radiation oncologist visual scores of the four algorithms ranged from 3.2 to 3.8, which indicated that the quality of transferred contours was “clinically acceptable with minor modification or major modification in a small number of contours

  4. Evaluation of radiation dose and image quality of CT scan for whole-body pediatric PET/CT: A phantom study

    SciTech Connect (OSTI)

    Yang, Ching-Ching; Liu, Shu-Hsin; Mok, Greta S. P.; Wu, Tung-Hsin

    2014-09-15

    Purpose: This study aimed to tailor the CT imaging protocols for pediatric patients undergoing whole-body PET/CT examinations with appropriate attention to radiation exposure while maintaining adequate image quality for anatomic delineation of PET findings and attenuation correction of PET emission data. Methods: The measurements were made by using three anthropomorphic phantoms representative of 1-, 5-, and 10-year-old children with tube voltages of 80, 100, and 120 kVp, tube currents of 10, 40, 80, and 120 mA, and exposure time of 0.5 s at 1.75:1 pitch. Radiation dose estimates were derived from the dose-length product and were used to calculate risk estimates for radiation-induced cancer. The influence of image noise on image contrast and attenuation map for CT scans were evaluated based on Pearson's correlation coefficient and covariance, respectively. Multiple linear regression methods were used to investigate the effects of patient age, tube voltage, and tube current on radiation-induced cancer risk and image noise for CT scans. Results: The effective dose obtained using three anthropomorphic phantoms and 12 combinations of kVp and mA ranged from 0.09 to 4.08 mSv. Based on our results, CT scans acquired with 80 kVp/60 mA, 80 kVp/80 mA, and 100 kVp/60 mA could be performed on 1-, 5-, and 10-year-old children, respectively, to minimize cancer risk due to CT scans while maintaining the accuracy of attenuation map and CT image contrast. The effective doses of the proposed protocols for 1-, 5- and 10-year-old children were 0.65, 0.86, and 1.065 mSv, respectively. Conclusions: Low-dose pediatric CT protocols were proposed to balance the tradeoff between radiation-induced cancer risk and image quality for patients ranging in age from 1 to 10 years old undergoing whole-body PET/CT examinations.

  5. QER Public Meeting in Providence, RI & Hartford, CT: New England Regional

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Infrastructure Constraints | Department of Energy Providence, RI & Hartford, CT: New England Regional Infrastructure Constraints QER Public Meeting in Providence, RI & Hartford, CT: New England Regional Infrastructure Constraints Meeting Date and Location: April 21, 2014 9:00A.M.. to 1:00 P.M. EST (Providence, RI) - 1:00 P.M. EST to 5:00 P.M. EST (Hartford, CT) Providence: Rhode Island Convention Center, 1 Sabin St., Ballroom B, Providence, RI Hartford: Connecticut Department of

  6. Iterative image-domain decomposition for dual-energy CT

    SciTech Connect (OSTI)

    Niu, Tianye; Dong, Xue; Petrongolo, Michael; Zhu, Lei

    2014-04-15

    Purpose: Dual energy CT (DECT) imaging plays an important role in advanced imaging applications due to its capability of material decomposition. Direct decomposition via matrix inversion suffers from significant degradation of image signal-to-noise ratios, which reduces clinical values of DECT. Existing denoising algorithms achieve suboptimal performance since they suppress image noise either before or after the decomposition and do not fully explore the noise statistical properties of the decomposition process. In this work, the authors propose an iterative image-domain decomposition method for noise suppression in DECT, using the full variance-covariance matrix of the decomposed images. Methods: The proposed algorithm is formulated in the form of least-square estimation with smoothness regularization. Based on the design principles of a best linear unbiased estimator, the authors include the inverse of the estimated variance-covariance matrix of the decomposed images as the penalty weight in the least-square term. The regularization term enforces the image smoothness by calculating the square sum of neighboring pixel value differences. To retain the boundary sharpness of the decomposed images, the authors detect the edges in the CT images before decomposition. These edge pixels have small weights in the calculation of the regularization term. Distinct from the existing denoising algorithms applied on the images before or after decomposition, the method has an iterative process for noise suppression, with decomposition performed in each iteration. The authors implement the proposed algorithm using a standard conjugate gradient algorithm. The method performance is evaluated using an evaluation phantom (Catphan600) and an anthropomorphic head phantom. The results are compared with those generated using direct matrix inversion with no noise suppression, a denoising method applied on the decomposed images, and an existing algorithm with similar formulation as the

  7. TH-E-17A-01: Internal Respiratory Surrogate for 4D CT Using Fourier...

    Office of Scientific and Technical Information (OSTI)

    E-17A-01: Internal Respiratory Surrogate for 4D CT Using Fourier Transform and Anatomical Features Citation Details In-Document Search Title: TH-E-17A-01: Internal Respiratory...

  8. DOE Zero Energy Ready Home Case Study: BPC Green Builders, Danbury, CT

    Broader source: Energy.gov [DOE]

    Case study of a DOE Zero Energy Ready home in Danbury, CT, that scored HERS 35 without PV. This 2-story, 1,650-ft2 cabin built by a custom home builder for his own family meets Passive House...

  9. Frequency and patterns of abnormality detected by iodine-123 amine emission CT after cerebral infarction

    SciTech Connect (OSTI)

    Brott, T.G.; Gelfand, M.J.; Williams, C.C.; Spilker, J.A.; Hertzberg, V.S.

    1986-03-01

    Single photon emission computed tomography (SPECT) was performed in 31 patients with cerebral infarction and 13 who had had transient ischemic attacks, using iodine-123-labeled N,N,N'-trimethyl-N'-(2-hydroxyl-3-methyl-5-iodobenzyl)-1,3-propanediamin e (I-123-HIPDM) as the radiopharmaceutical. SPECT scans were compared with computed tomographic (CT) scans. SPECT was as sensitive as CT in detecting cerebral infarction (94% vs. 84%). The abnormalities were larger on the SPECT scans than on the CT scans in 19 cases, equal in seven, and smaller in five (SPECT abnormalities greater than or equal to CT abnormalities in 86% of cases). Fifteen of 30 patients with hemispheric infarction had decreased perfusion (decreased uptake of I-123-HIPDM) to the cerebellar hemisphere contralateral to the cerebral hemisphere involved by the infarction (crossed cerebellar diaschisis). Nine of these 15 patients had major motor deficits, while only one of the 15 without crossed cerebellar diaschisis had a major motor deficit.

  10. Low-Dose Spiral CT Scans for Early Lung Cancer Detection

    Broader source: Energy.gov [DOE]

    Low-dose spiral computed tomography (CT) scanning is a noninvasive medical imaging test that has been used for the early detection of lung cancer for over 16 years (Sone et al. 1998; Henschke et.al. 1999).

  11. High energy x-ray phase contrast CT using glancing-angle grating interferometers

    SciTech Connect (OSTI)

    Sarapata, A.; Stayman, J. W.; Siewerdsen, J. H.; Finkenthal, M.; Stutman, D.; Pfeiffer, F.

    2014-02-15

    Purpose: The authors present initial progress toward a clinically compatible x-ray phase contrast CT system, using glancing-angle x-ray grating interferometry to provide high contrast soft tissue images at estimated by computer simulation dose levels comparable to conventional absorption based CT. Methods: DPC-CT scans of a joint phantom and of soft tissues were performed in order to answer several important questions from a clinical setup point of view. A comparison between high and low fringe visibility systems is presented. The standard phase stepping method was compared with sliding window interlaced scanning. Using estimated dose values obtained with a Monte-Carlo code the authors studied the dependence of the phase image contrast on exposure time and dose. Results: Using a glancing angle interferometer at high x-ray energy (∼45 keV mean value) in combination with a conventional x-ray tube the authors achieved fringe visibility values of nearly 50%, never reported before. High fringe visibility is shown to be an indispensable parameter for a potential clinical scanner. Sliding window interlaced scanning proved to have higher SNRs and CNRs in a region of interest and to also be a crucial part of a low dose CT system. DPC-CT images of a soft tissue phantom at exposures in the range typical for absorption based CT of musculoskeletal extremities were obtained. Assuming a human knee as the CT target, good soft tissue phase contrast could be obtained at an estimated absorbed dose level around 8 mGy, similar to conventional CT. Conclusions: DPC-CT with glancing-angle interferometers provides improved soft tissue contrast over absorption CT even at clinically compatible dose levels (estimated by a Monte-Carlo computer simulation). Further steps in image processing, data reconstruction, and spectral matching could make the technique fully clinically compatible. Nevertheless, due to its increased scan time and complexity the technique should be thought of not as

  12. Objective assessment of image quality and dose reduction in CT iterative reconstruction

    SciTech Connect (OSTI)

    Vaishnav, J. Y. Jung, W. C.; Popescu, L. M.; Zeng, R.; Myers, K. J.

    2014-07-15

    Purpose: Iterative reconstruction (IR) algorithms have the potential to reduce radiation dose in CT diagnostic imaging. As these algorithms become available on the market, a standardizable method of quantifying the dose reduction that a particular IR method can achieve would be valuable. Such a method would assist manufacturers in making promotional claims about dose reduction, buyers in comparing different devices, physicists in independently validating the claims, and the United States Food and Drug Administration in regulating the labeling of CT devices. However, the nonlinear nature of commercially available IR algorithms poses challenges to objectively assessing image quality, a necessary step in establishing the amount of dose reduction that a given IR algorithm can achieve without compromising that image quality. This review paper seeks to consolidate information relevant to objectively assessing the quality of CT IR images, and thereby measuring the level of dose reduction that a given IR algorithm can achieve. Methods: The authors discuss task-based methods for assessing the quality of CT IR images and evaluating dose reduction. Results: The authors explain and review recent literature on signal detection and localization tasks in CT IR image quality assessment, the design of an appropriate phantom for these tasks, possible choices of observers (including human and model observers), and methods of evaluating observer performance. Conclusions: Standardizing the measurement of dose reduction is a problem of broad interest to the CT community and to public health. A necessary step in the process is the objective assessment of CT image quality, for which various task-based methods may be suitable. This paper attempts to consolidate recent literature that is relevant to the development and implementation of task-based methods for the assessment of CT IR image quality.

  13. SU-E-P-46: Clinical Acceptance Testing and Implementation of a Portable CT Unit

    SciTech Connect (OSTI)

    LaFrance, M; Marsh, S; Hicks, R; O’Donnell-Moran, G

    2015-06-15

    Purpose: Planning for the first installation in New England of a new portable CT unit to be used in the Operating Room required the integration of many departments including Surgery, Neurosurgery, Information Services, Clinical Engineering, Radiology and Medical Physics/Radiation Safety. Acceptance testing and the quality assurance procedures were designed to optimize image quality and patient and personnel radiation exposure. Methods: The vendor’s protocols were tested using the CT Dosimetry phantoms. The system displayed the CTDIw instead of the CTDIvol while testing the unit. Radiation exposure was compared to existing CT scanners from installed CT units throughout the facility. Brainlab measures all 4 periphery slots on the CT Dosimetry phantom. The ACR measures only the superior slot for the periphery measurement. A comprehensive radiation survey was also performed for several locations. Results: The CTDIvol measurements were comparable for the following studies: brain, C-Spine, and sinuses. However, the mobile CT measurements were slightly higher than other CT units but within acceptable tolerance if measured using the ACR method.Based on scatter measurements, it was determined if any personnel were to stay in the OR Suite during image acquisition that the appropriate lead apron and thyroid shields had to be worn.In addition, to reduce unnecessary scatter, there were two mobile 6 foot wide shields (1/16″ lead equivalent) available to protect personnel in the room and adjacent areas. Conclusion: Intraoperative CT provides the physician new opportunities for evaluation of the progression of surgical resections and device placement at the cost of increasing the amount of trained personnel required to perform this procedure. It also brings with it challenges to keep the radiation exposure to the patients and staff within reasonable limits.

  14. The effects of mapping CT images to Monte Carlo materials on GEANT4 proton simulation accuracy

    SciTech Connect (OSTI)

    Barnes, Samuel; McAuley, Grant; Slater, James; Wroe, Andrew

    2013-04-15

    Purpose: Monte Carlo simulations of radiation therapy require conversion from Hounsfield units (HU) in CT images to an exact tissue composition and density. The number of discrete densities (or density bins) used in this mapping affects the simulation accuracy, execution time, and memory usage in GEANT4 and other Monte Carlo code. The relationship between the number of density bins and CT noise was examined in general for all simulations that use HU conversion to density. Additionally, the effect of this on simulation accuracy was examined for proton radiation. Methods: Relative uncertainty from CT noise was compared with uncertainty from density binning to determine an upper limit on the number of density bins required in the presence of CT noise. Error propagation analysis was also performed on continuously slowing down approximation range calculations to determine the proton range uncertainty caused by density binning. These results were verified with Monte Carlo simulations. Results: In the presence of even modest CT noise (5 HU or 0.5%) 450 density bins were found to only cause a 5% increase in the density uncertainty (i.e., 95% of density uncertainty from CT noise, 5% from binning). Larger numbers of density bins are not required as CT noise will prevent increased density accuracy; this applies across all types of Monte Carlo simulations. Examining uncertainty in proton range, only 127 density bins are required for a proton range error of <0.1 mm in most tissue and <0.5 mm in low density tissue (e.g., lung). Conclusions: By considering CT noise and actual range uncertainty, the number of required density bins can be restricted to a very modest 127 depending on the application. Reducing the number of density bins provides large memory and execution time savings in GEANT4 and other Monte Carlo packages.

  15. Evaluation of the OSC-TV iterative reconstruction algorithm for cone-beam optical CT

    SciTech Connect (OSTI)

    Matenine, Dmitri Mascolo-Fortin, Julia; Goussard, Yves

    2015-11-15

    Purpose: The present work evaluates an iterative reconstruction approach, namely, the ordered subsets convex (OSC) algorithm with regularization via total variation (TV) minimization in the field of cone-beam optical computed tomography (optical CT). One of the uses of optical CT is gel-based 3D dosimetry for radiation therapy, where it is employed to map dose distributions in radiosensitive gels. Model-based iterative reconstruction may improve optical CT image quality and contribute to a wider use of optical CT in clinical gel dosimetry. Methods: This algorithm was evaluated using experimental data acquired by a cone-beam optical CT system, as well as complementary numerical simulations. A fast GPU implementation of OSC-TV was used to achieve reconstruction times comparable to those of conventional filtered backprojection. Images obtained via OSC-TV were compared with the corresponding filtered backprojections. Spatial resolution and uniformity phantoms were scanned and respective reconstructions were subject to evaluation of the modulation transfer function, image uniformity, and accuracy. The artifacts due to refraction and total signal loss from opaque objects were also studied. Results: The cone-beam optical CT data reconstructions showed that OSC-TV outperforms filtered backprojection in terms of image quality, thanks to a model-based simulation of the photon attenuation process. It was shown to significantly improve the image spatial resolution and reduce image noise. The accuracy of the estimation of linear attenuation coefficients remained similar to that obtained via filtered backprojection. Certain image artifacts due to opaque objects were reduced. Nevertheless, the common artifact due to the gel container walls could not be eliminated. Conclusions: The use of iterative reconstruction improves cone-beam optical CT image quality in many ways. The comparisons between OSC-TV and filtered backprojection presented in this paper demonstrate that OSC-TV can

  16. 10 A.M. CT TODAY: On-the Record Conference Call for Obama Administration to

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Announce Major Initiative to Enhance America's Energy Security | Department of Energy A.M. CT TODAY: On-the Record Conference Call for Obama Administration to Announce Major Initiative to Enhance America's Energy Security 10 A.M. CT TODAY: On-the Record Conference Call for Obama Administration to Announce Major Initiative to Enhance America's Energy Security August 16, 2011 - 9:52am Addthis White House Rural Economic Council Promotes Production of Next Generation Biofuels, Job Creation and

  17. Determination of CT number and density profile of binderless, pre-treated and tannin-based Rhizophora spp. particleboards using computed tomography imaging and electron density phantom

    SciTech Connect (OSTI)

    Yusof, Mohd Fahmi Mohd Hamid, Puteri Nor Khatijah Abdul; Tajuddin, Abdul Aziz; Bauk, Sabar; Hashim, Rokiah

    2015-04-29

    Plug density phantoms were constructed in accordance to CT density phantom model 062M CIRS using binderless, pre-treated and tannin-based Rhizophora Spp. particleboards. The Rhizophora Spp. plug phantoms were scanned along with the CT density phantom using Siemens Somatom Definition AS CT scanner at three CT energies of 80, 120 and 140 kVp. 15 slices of images with 1.0 mm thickness each were taken from the central axis of CT density phantom for CT number and CT density profile analysis. The values were compared to water substitute plug phantom from the CT density phantom. The tannin-based Rhizophora Spp. gave the nearest value of CT number to water substitute at 80 and 120 kVp CT energies with χ{sup 2} value of 0.011 and 0.014 respectively while the binderless Rhizphora Spp. gave the nearest CT number to water substitute at 140 kVp CT energy with χ{sup 2} value of 0.023. The tannin-based Rhizophora Spp. gave the nearest CT density profile to water substitute at all CT energies. This study indicated the suitability of Rhizophora Spp. particleboard as phantom material for the use in CT imaging studies.

  18. SU-C-9A-06: The Impact of CT Image Used for Attenuation Correction in 4D-PET

    SciTech Connect (OSTI)

    Cui, Y; Bowsher, J; Yan, S; Cai, J; Das, S; Yin, F

    2014-06-01

    Purpose: To evaluate the appropriateness of using 3D non-gated CT image for attenuation correction (AC) in a 4D-PET (gated PET) imaging protocol used in radiotherapy treatment planning simulation. Methods: The 4D-PET imaging protocol in a Siemens PET/CT simulator (Biograph mCT, Siemens Medical Solutions, Hoffman Estates, IL) was evaluated. CIRS Dynamic Thorax Phantom (CIRS Inc., Norfolk, VA) with a moving glass sphere (8 mL) in the middle of its thorax portion was used in the experiments. The glass was filled with {sup 18}F-FDG and was in a longitudinal motion derived from a real patient breathing pattern. Varian RPM system (Varian Medical Systems, Palo Alto, CA) was used for respiratory gating. Both phase-gating and amplitude-gating methods were tested. The clinical imaging protocol was modified to use three different CT images for AC in 4D-PET reconstruction: first is to use a single-phase CT image to mimic actual clinical protocol (single-CT-PET); second is to use the average intensity projection CT (AveIP-CT) derived from 4D-CT scanning (AveIP-CT-PET); third is to use 4D-CT image to do the phase-matched AC (phase-matching- PET). Maximum SUV (SUVmax) and volume of the moving target (glass sphere) with threshold of 40% SUVmax were calculated for comparison between 4D-PET images derived with different AC methods. Results: The SUVmax varied 7.3%±6.9% over the breathing cycle in single-CT-PET, compared to 2.5%±2.8% in AveIP-CT-PET and 1.3%±1.2% in phasematching PET. The SUVmax in single-CT-PET differed by up to 15% from those in phase-matching-PET. The target volumes measured from single- CT-PET images also presented variations up to 10% among different phases of 4D PET in both phase-gating and amplitude-gating experiments. Conclusion: Attenuation correction using non-gated CT in 4D-PET imaging is not optimal process for quantitative analysis. Clinical 4D-PET imaging protocols should consider phase-matched 4D-CT image if available to achieve better accuracy.

  19. MO-E-17A-03: Monte Carlo CT Dose Calculation: A Comparison Between Experiment and Simulation Using ARCHER-CT

    SciTech Connect (OSTI)

    Liu, T; Du, X; Su, L; Gao, Y; Ji, W; Xu, X; Zhang, D; Shi, J; Liu, B; Kalra, M

    2014-06-15

    Purpose: To compare the CT doses derived from the experiments and GPU-based Monte Carlo (MC) simulations, using a human cadaver and ATOM phantom. Methods: The cadaver of an 88-year old male and the ATOM phantom were scanned by a GE LightSpeed Pro 16 MDCT. For the cadaver study, the Thimble chambers (Model 105?0.6CT and 106?0.6CT) were used to measure the absorbed dose in different deep and superficial organs. Whole-body scans were first performed to construct a complete image database for MC simulations. Abdomen/pelvis helical scans were then conducted using 120/100 kVps, 300 mAs and a pitch factor of 1.375:1. For the ATOM phantom study, the OSL dosimeters were used and helical scans were performed using 120 kVp and x, y, z tube current modulation (TCM). For the MC simulations, sufficient particles were run in both cases such that the statistical errors of the results by ARCHER-CT were limited to 1%. Results: For the human cadaver scan, the doses to the stomach, liver, colon, left kidney, pancreas and urinary bladder were compared. The difference between experiments and simulations was within 19% for the 120 kVp and 25% for the 100 kVp. For the ATOM phantom scan, the doses to the lung, thyroid, esophagus, heart, stomach, liver, spleen, kidneys and thymus were compared. The difference was 39.2% for the esophagus, and within 16% for all other organs. Conclusion: In this study the experimental and simulated CT doses were compared. Their difference is primarily attributed to the systematic errors of the MC simulations, including the accuracy of the bowtie filter modeling, and the algorithm to generate voxelized phantom from DICOM images. The experimental error is considered small and may arise from the dosimeters. R01 grant (R01EB015478) from National Institute of Biomedical Imaging and Bioengineering.

  20. A minimum spanning forest based classification method for dedicated breast CT images

    SciTech Connect (OSTI)

    Pike, Robert; Sechopoulos, Ioannis; Fei, Baowei

    2015-11-15

    Purpose: To develop and test an automated algorithm to classify different types of tissue in dedicated breast CT images. Methods: Images of a single breast of five different patients were acquired with a dedicated breast CT clinical prototype. The breast CT images were processed by a multiscale bilateral filter to reduce noise while keeping edge information and were corrected to overcome cupping artifacts. As skin and glandular tissue have similar CT values on breast CT images, morphologic processing is used to identify the skin based on its position information. A support vector machine (SVM) is trained and the resulting model used to create a pixelwise classification map of fat and glandular tissue. By combining the results of the skin mask with the SVM results, the breast tissue is classified as skin, fat, and glandular tissue. This map is then used to identify markers for a minimum spanning forest that is grown to segment the image using spatial and intensity information. To evaluate the authors’ classification method, they use DICE overlap ratios to compare the results of the automated classification to those obtained by manual segmentation on five patient images. Results: Comparison between the automatic and the manual segmentation shows that the minimum spanning forest based classification method was able to successfully classify dedicated breast CT image with average DICE ratios of 96.9%, 89.8%, and 89.5% for fat, glandular, and skin tissue, respectively. Conclusions: A 2D minimum spanning forest based classification method was proposed and evaluated for classifying the fat, skin, and glandular tissue in dedicated breast CT images. The classification method can be used for dense breast tissue quantification, radiation dose assessment, and other applications in breast imaging.

  1. Multienergy CT acquisition and reconstruction with a stepped tube potential scan

    SciTech Connect (OSTI)

    Shen, Le; Xing, Yuxiang

    2015-01-15

    Purpose: Based on an energy-dependent property of matter, one may obtain a pseudomonochromatic attenuation map, a material composition image, an electron-density distribution, and an atomic number image using a dual- or multienergy computed tomography (CT) scan. Dual- and multienergy CT scans broaden the potential of x-ray CT imaging. The development of such systems is very useful in both medical and industrial investigations. In this paper, the authors propose a new dual- and multienergy CT system design (segmental multienergy CT, SegMECT) using an innovative scanning scheme that is conveniently implemented on a conventional single-energy CT system. The two-step-energy dual-energy CT can be regarded as a special case of SegMECT. A special reconstruction method is proposed to support SegMECT. Methods: In their SegMECT, a circular trajectory in a CT scan is angularly divided into several arcs. The x-ray source is set to a different tube voltage for each arc of the trajectory. Thus, the authors only need to make a few step changes to the x-ray energy during the scan to complete a multienergy data acquisition. With such a data set, the image reconstruction might suffer from severe limited-angle artifacts if using conventional reconstruction methods. To solve the problem, they present a new prior-image-based reconstruction technique using a total variance norm of a quotient image constraint. On the one hand, the prior extracts structural information from all of the projection data. On the other hand, the effect from a possibly imprecise intensity level of the prior can be mitigated by minimizing the total variance of a quotient image. Results: The authors present a new scheme for a SegMECT configuration and establish a reconstruction method for such a system. Both numerical simulation and a practical phantom experiment are conducted to validate the proposed reconstruction method and the effectiveness of the system design. The results demonstrate that the proposed Seg

  2. Application of the optically stimulated luminescence (OSL) technique for mouse dosimetry in micro-CT imaging

    SciTech Connect (OSTI)

    Vrigneaud, Jean-Marc; Courteau, Alan; Oudot, Alexandra; Collin, Bertrand; Ranouil, Julien; Morgand, Loïc; Raguin, Olivier; Walker, Paul; Brunotte, François

    2013-12-15

    Purpose: Micro-CT is considered to be a powerful tool to investigate various models of disease on anesthetized animals. In longitudinal studies, the radiation dose delivered by the micro-CT to the same animal is a major concern as it could potentially induce spurious effects in experimental results. Optically stimulated luminescence dosimeters (OSLDs) are a relatively new kind of detector used in radiation dosimetry for medical applications. The aim of this work was to assess the dose delivered by the CT component of a micro-SPECT (single-photon emission computed tomography)/CT camera during a typical whole-body mouse study, using commercially available OSLDs based on Al{sub 2}O{sub 3}:C crystals.Methods: CTDI (computed tomography dose index) was measured in micro-CT with a properly calibrated pencil ionization chamber using a rat-like phantom (60 mm in diameter) and a mouse-like phantom (30 mm in diameter). OSLDs were checked for reproducibility and linearity in the range of doses delivered by the micro-CT. Dose measurements obtained with OSLDs were compared to those of the ionization chamber to correct for the radiation quality dependence of OSLDs in the low-kV range. Doses to tissue were then investigated in phantoms and cadavers. A 30 mm diameter phantom, specifically designed to insert OSLDs, was used to assess radiation dose over a typical whole-body mouse imaging study. Eighteen healthy female BALB/c mice weighing 27.1 ± 0.8 g (1 SD) were euthanized for small animal measurements. OLSDs were placed externally or implanted internally in nine different locations by an experienced animal technician. Five commonly used micro-CT protocols were investigated.Results: CTDI measurements were between 78.0 ± 2.1 and 110.7 ± 3.0 mGy for the rat-like phantom and between 169.3 ± 4.6 and 203.6 ± 5.5 mGy for the mouse-like phantom. On average, the displayed CTDI at the operator console was underestimated by 1.19 for the rat-like phantom and 2.36 for the mouse

  3. SU-E-J-267: Change in Mean CT Intensity of Lung Tumors During Radiation Treatment

    SciTech Connect (OSTI)

    Mahon, R; Tennyson, N; Weiss, E; Hugo, G

    2015-06-15

    Purpose: To evaluate CT intensity change of lung tumors during radiation therapy. Methods: Repeated 4D CT images were acquired on a CT simulator during the course of therapy for 27 lung cancer patients on IRB approved protocols. All subjects received definitive radiation treatment ± chemotherapy. CT scans were completed prior to treatment, and 2–7 times during the treatment course. Primary tumor was delineated by an experienced Radiation Oncologist. Contours were thresholded between −100 HU and 200 HU to remove airways and bone. Correlations between the change in the mean tumor intensity and initial tumor intensity, SUVmax, and tumor volume change rate were investigated. Reproducibility was assessed by evaluating the variation in mean intensity over all phases in 4DCT, for a subgroup of 19 subjects. Results: Reproducibility of tumor intensity between phases as characterized by the root mean square of standard deviation across 19 subjects was 1.8 HU. Subjects had a mean initial tumor intensity of 16.5 ± 11.6 HU and an overall reduction in HU by 10.3 ± 8.5 HU. Evaluation of the changes in tumor intensity during treatment showed a decrease of 0.3 ± 0.3 HU/day for all subjects, except three. No significant correlation was found between change in HU/day and initial HU intensity (p=0.53), initial PET SUVmax (p=0.69), or initial tumor volume (p=0.70). The rate of tumor volume change was weakly correlated (R{sup 2}=0.05) with HU change (p=0.01). Conclusion: Most lung cancer subjects showed a marked trend of decreasing mean tumor CT intensity throughout radiotherapy, including early in the treatment course. Change in HU/day is not correlated with other potential early predictors for response, such as SUV and tumor volume change. This Result supports future studies to evaluate change in tumor intensity on CT as an early predictor of response.

  4. Resolution enhancement of lung 4D-CT data using multiscale interphase iterative nonlocal means

    SciTech Connect (OSTI)

    Zhang Yu; Yap, Pew-Thian; Wu Guorong; Feng Qianjin; Chen Wufan; Lian Jun; Shen Dinggang

    2013-05-15

    Purpose: Four-dimensional computer tomography (4D-CT) has been widely used in lung cancer radiotherapy due to its capability in providing important tumor motion information. However, the prolonged scanning duration required by 4D-CT causes considerable increase in radiation dose. To minimize the radiation-related health risk, radiation dose is often reduced at the expense of interslice spatial resolution. However, inadequate resolution in 4D-CT causes artifacts and increases uncertainty in tumor localization, which eventually results in extra damages of healthy tissues during radiotherapy. In this paper, the authors propose a novel postprocessing algorithm to enhance the resolution of lung 4D-CT data. Methods: The authors' premise is that anatomical information missing in one phase can be recovered from the complementary information embedded in other phases. The authors employ a patch-based mechanism to propagate information across phases for the reconstruction of intermediate slices in the longitudinal direction, where resolution is normally the lowest. Specifically, the structurally matching and spatially nearby patches are combined for reconstruction of each patch. For greater sensitivity to anatomical details, the authors employ a quad-tree technique to adaptively partition the image for more fine-grained refinement. The authors further devise an iterative strategy for significant enhancement of anatomical details. Results: The authors evaluated their algorithm using a publicly available lung data that consist of 10 4D-CT cases. The authors' algorithm gives very promising results with significantly enhanced image structures and much less artifacts. Quantitative analysis shows that the authors' algorithm increases peak signal-to-noise ratio by 3-4 dB and the structural similarity index by 3%-5% when compared with the standard interpolation-based algorithms. Conclusions: The authors have developed a new algorithm to improve the resolution of 4D-CT. It outperforms

  5. SU-E-I-68: Practical Considerations On Implementation of the Image Gently Pediatric CT Protocols

    SciTech Connect (OSTI)

    Zhang, J; Adams, C; Lumby, C; Dillon, J; Woods, E; Richer, E

    2014-06-01

    Purpose: One limitation associated with the Image Gently pediatric CT protocols is practical implementation of the recommended manual techniques. Inconsistency as a result of different practice is a possibility among technologist. An additional concern is the added risk of data error that would result in over or underexposure. The Automatic Exposure Control (AEC) features automatically reduce radiation for children. However, they do not work efficiently for the patients of very small size and relative large size. This study aims to implement the Image Gently pediatric CT protocols in the practical setting while maintaining the use of AEC features for pediatric patients of varying size. Methods: Anthropomorphological abdomen phantoms were scanned in a CT scanner using the Image Gently pediatric protocols, the AEC technique with a fixed adult baseline, and automatic protocols with various baselines. The baselines were adjusted corresponding to patient age, weight and posterioranterior thickness to match the Image Gently pediatric CT manual techniques. CTDIvol was recorded for each examination. Image noise was measured and recorded for image quality comparison. Clinical images were evaluated by pediatric radiologists. Results: By adjusting vendor default baselines used in the automatic techniques, radiation dose and image quality can match those of the Image Gently manual techniques. In practice, this can be achieved by dividing pediatric patients into three major groups for technologist reference: infant, small child, and large child. Further division can be done but will increase the number of CT protocols. For each group, AEC can efficiently adjust acquisition techniques for children. This implementation significantly overcomes the limitation of the Image Gently manual techniques. Conclusion: Considering the effectiveness in clinical practice, Image Gently Pediatric CT protocols can be implemented in accordance with AEC techniques, with adjusted baselines, to

  6. Bowtie filters for dedicated breast CT: Theory and computational implementation

    SciTech Connect (OSTI)

    Kontson, Kimberly Jennings, Robert J.

    2015-03-15

    Purpose: To design bowtie filters with improved properties for dedicated breast CT to improve image quality and reduce dose to the patient. Methods: The authors present three different bowtie filters designed for a cylindrical 14-cm diameter phantom with a uniform composition of 40/60 breast tissue, which vary in their design objectives and performance improvements. Bowtie design #1 is based on single material spectral matching and produces nearly uniform spectral shape for radiation incident upon the detector. Bowtie design #2 uses the idea of basis material decomposition to produce the same spectral shape and intensity at the detector, using two different materials. Bowtie design #3 eliminates the beam hardening effect in the reconstructed image by adjusting the bowtie filter thickness so that the effective attenuation coefficient for every ray is the same. All three designs are obtained using analytical computational methods and linear attenuation coefficients. Thus, the designs do not take into account the effects of scatter. The authors considered this to be a reasonable approach to the filter design problem since the use of Monte Carlo methods would have been computationally intensive. The filter profiles for a cone-angle of 0° were used for the entire length of each filter because the differences between those profiles and the correct cone-beam profiles for the cone angles in our system are very small, and the constant profiles allowed construction of the filters with the facilities available to us. For evaluation of the filters, we used Monte Carlo simulation techniques and the full cone-beam geometry. Images were generated with and without each bowtie filter to analyze the effect on dose distribution, noise uniformity, and contrast-to-noise ratio (CNR) homogeneity. Line profiles through the reconstructed images generated from the simulated projection images were also used as validation for the filter designs. Results: Examples of the three designs are

  7. Evaluating the Influence of Wall-Roughness on Fracture Transmissivity with CT Scanning and Flow Simulations

    SciTech Connect (OSTI)

    Crandall, Dustin; Bromhal, Grant; McIntyre, Dustin

    2010-01-01

    Combining CT imaging of geomaterials with computational fluid dynamics provides substantial benefits to researchers. With simulations, geometric parameters can be varied in systematic ways that are not possible in the lab. This paper details the conversion of micro-CT images of a physical fracture in Berea sandstone to several tractable finite volume meshes. By computationally varying the level of detail captured from the scans we produced several realistic fracture geometries with different degrees of wall-roughness and various geometric properties. Simulations were performed and it was noted that increasing roughness increased the resistance to fluid flow. Also, as the distance between walls was increased the mean aperture approached the effective aperture.

  8. United States Government

    Office of Legacy Management (LM)

    The s ite is owned by the Crane Company, 100 Stamford Place, Stamford, Connecticut. This designation is based on the results of a radiological survey and conclus ions from an ...

  9. Pilot Study to Confirm that Fat and Liver can be Distinguished by Spectroscopic Tissue Response on a Medipix-All-Resolution System-CT (MARS-CT)

    SciTech Connect (OSTI)

    Berg, Kyra B.; Anderson, Nigel G.; Butler, Alexandra P.; Carr, James M.; Clark, Michael J.; Cook, Nick J.; Scott, Nicola J.; Butler, Philip H.; Butler, Anthony P.

    2009-07-23

    NAFLD, liver component of the 'metabolic' syndrome, has become the most common liver disease in western nations. Non-invasive imaging techniques exist, but have limitations, especially in detection and quantification of mild to moderate fatty liver. In this pilot study, we produced attenuation curves from biomedical-quality projection images of liver and fat using the MARS spectroscopic-CT scanner. Difficulties obtaining attenuation spectra after reconstruction demonstrated that standard reconstruction programs do not preserve spectral information.

  10. TU-PIS-Exhibit Hall-01: CT Dose Optimization Technologies II

    SciTech Connect (OSTI)

    Driesser, I; Angel, E

    2014-06-15

    Partners in Solutions is an exciting new program in which AAPM partners with our vendors to present practical “hands-on” information about the equipment and software systems that we use in our clinics. The imaging topic this year is CT scanner dose optimization capabilities. Note that the sessions are being held in a special purpose room built on the Exhibit Hall Floor, to encourage further interaction with the vendors. Siemens‘ Commitment to the Right Dose in Computed Tomography Presentation Time: 11:15 - 11:45 AM Providing sustainable clinical results at highest patient safety: This is the challenge in medical imaging. Especially for Computed Tomography this means applying not simply the lowest, but the right dose for sound diagnostic imaging. Consequently, Siemens is committed to deliver the right dose in CT. In order to reduce radiation to the right dose, the first step is to provide the right dose technology. Through decades of research and development in CT imaging, Siemens CT has constantly introduced new ideas leading to a comprehensive portfolio of unique CARE technologies to deliver the right dose. For example automated kV adjustment based on patient size and the clinical question with CARE kV and three generations of iterative reconstruction. Based on the right dose technology, the next step is to actually scan at the right dose. For this, it is key to know the right dose targets for every examination. Siemens continuously involves CT experts to push developments further and outline how users can best adapt their procedures to the right dose. For users to know whether they met the right dose targets, it is therefore important to understand and monitor the actual absolute dose values. All scanners are delivered with defined default protocols which automatically use the available right dose technologies. Finally, to deliver the right dose not just in singular cases, but ideally to patients everywhere, organizations need then to manage dose across

  11. MO-E-17A-01: BEST IN PHYSICS (IMAGING) - Calculating SSDE From CT Exams Using Size Data Available in the DICOM Header of CT Localizer Radiographs

    SciTech Connect (OSTI)

    McMillan, K; Bostani, M; McNitt-Gray, M; McCollough, C

    2014-06-15

    Purpose: To demonstrate the feasibility of using existing data stored within the DICOM header of certain CT localizer radiographs as a patient size metric for calculating CT size-specific dose estimates (SSDE). Methods: For most Siemens CT scanners, the CT localizer radiograph (topogram) contains a private DICOM field that stores an array of numbers describing AP and LAT attenuation-based measures of patient dimension. The square root of the product of the AP and LAT size data, which provides an estimate of water-equivalent-diameter (WED), was calculated retrospectively from topogram data of 20 patients who received clinically-indicated abdomen/pelvis (n=10) and chest (n=10) scans (WED-topo). In addition, slice-by-slice water-equivalent-diameter (WED-image) and effective diameter (ED-image) values were calculated from the respective image data. Using TG-204 lookup tables, size-dependent conversion factors were determined based upon WED-topo, WED-image and ED-image values. These conversion factors were used with the reported CTDIvol to calculate slice-by-slice SSDE for each method. Averaging over all slices, a single SSDE value was determined for each patient and size metric. Patientspecific SSDE and CTDIvol values were then compared with patientspecific organ doses derived from detailed Monte Carlo simulations of fixed tube current scans. Results: For abdomen/pelvis scans, the average difference between liver dose and CTDIvol, SSDE(WED-topo), SSDE(WED-image), and SSDE(ED-image) was 18.70%, 8.17%, 6.84%, and 7.58%, respectively. For chest scans, the average difference between lung dose and CTDIvol, SSDE(WED-topo), SSDE(WED-image), and SSDE(ED-image) was 25.80%, 3.33%, 4.11%, and 7.66%, respectively. Conclusion: SSDE calculated using WED derived from data in the DICOM header of the topogram was comparable to SSDE calculated using WED and ED derived from axial images; each of these estimated organ dose to within 10% for both abdomen/pelvis and chest CT examinations

  12. SU-E-I-31: Differences Observed in Radiation Doses Across 2 Similar CT Scanners From Adult Brain-Neck CT Angiography

    SciTech Connect (OSTI)

    Fujii, K; McMillan, K; Bostani, M; Cagnon, C; McNitt-Gray, M

    2015-06-15

    Purpose: The aim of this study is to evaluate the difference in radiation doses from adult Brain-Neck CT angiography (CTA) between two CT scanners. Methods: We collected CT dose index data (CTDIvol, DLP) from adult Brain-Neck CTA performed with two CT scanners (Sensation 64 (S64) and Definition AS (AS), Siemens Healthcare) performed at two of our facilities from Jan 1st to Dec 31th, 2014. X-ray dose management software (Radmetrics, Bayer Healthcare) was used to mine these data. All exams were performed with Tube Current Modulation (Care Dose 4D), tube voltage of 120 kVp, quality reference mAs of 300, beam collimation of 64*0.6 mm. The rotation time was set to 0.5 sec for S64 and 1.0 sec for AS. We also scanned an anthropomorphic skull and chest phantom under routine Brain-Neck CTA protocol with the two scanners and extracted the tube current values from the raw projection data. Results: The mean CTDIvol and DLP in Brain-Neck CTA was 72 mGy and 2554 mGy*cm for AS, which was substantially larger than the mean values of 46 mGy and 1699 mGy*cm for S64. The maximum tube current was 583 mA for most cases on the S64 while the maximum was 666 mA for AS even though the rotation time set for AS was 1.0 sec. Measurements obtained with the anthropomorphic phantom showed that the tube current reached 583 mA at the shoulder region for S64 while it reached to 666 mA for AS. Conclusion: The results of this study showed that substantially different CT doses can Result from Brain-Neck CTA protocols even when similar scanners and similar settings are used. Though both scanners have a similar maximum mA rating, differences in mA were observed through the shoulders, resulting in substantially different CTDIvol values.

  13. The feasibility of head motion tracking in helical CT: A step toward motion correction

    SciTech Connect (OSTI)

    Kim, Jung-Ha; Nuyts, Johan; Kuncic, Zdenka; Fulton, Roger

    2013-04-15

    Purpose: To establish a practical and accurate motion tracking method for the development of rigid motion correction methods in helical x-ray computed tomography (CT). Methods: A commercially available optical motion tracking system provided 6 degrees of freedom pose measurements at 60 Hz. A 4 Multiplication-Sign 4 calibration matrix was determined to convert raw pose data acquired in tracker coordinates to a fixed CT coordinate system with origin at the isocenter of the scanner. Two calibration methods, absolute orientation (AO), and a new method based on image registration (IR), were compared by means of landmark analysis and correlation coefficient in phantom images coregistered using the derived motion transformations. Results: Transformations calculated using the IR-derived calibration matrix were found to be more accurate, with positional errors less than 0.5 mm (mean RMS), and highly correlated image voxel intensities. The AO-derived calibration matrix yielded larger mean RMS positional errors ( Asymptotically-Equal-To 1.0 mm), and poorer correlation coefficients. Conclusions: The authors have demonstrated the feasibility of accurate motion tracking for retrospective motion correction in helical CT. Their new IR-based calibration method based on image registration and function minimization was simpler to perform and delivered more accurate calibration matrices. This technique is a useful tool for future work on rigid motion correction in helical CT and potentially also other imaging modalities.

  14. DOE Zero Energy Ready Home Case Study: Brookside Development, Derby, CT

    Broader source: Energy.gov [DOE]

    Case study of a DOE Zero Energy Ready home in Derby, CT, that achieves a HERS score of 45 without PV or HERS 26 with PV. The production home is one of a development of 7 two-story, 4,000+-ft2...

  15. Technical Note: Measurement of bow tie profiles in CT scanners using radiochromic film

    SciTech Connect (OSTI)

    Whiting, Bruce R.; Dohatcu, Andreea C.; Evans, Joshua D.; Williamson, Jeffrey F.; Politte, David G.

    2015-06-15

    Purpose: To provide a noninvasive technique to measure the intensity profile of the fan beam in a computed tomography (CT) scanner that is cost effective and easily implemented without the need to access proprietary scanner information or service modes. Methods: The fabrication of an inexpensive aperture is described, which is used to expose radiochromic film in a rotating CT gantry. A series of exposures is made, each of which is digitized on a personal computer document scanner, and the resulting data set is analyzed to produce a self-consistent calibration of relative radiation exposure. The bow tie profiles were analyzed to determine the precision of the process and were compared to two other measurement techniques, direct measurements from CT gantry detectors and a dynamic dosimeter. Results: The radiochromic film method presented here can measure radiation exposures with a precision of ∼6% root-mean-square relative error. The intensity profiles have a maximum 25% root-mean-square relative error compared with existing techniques. Conclusions: The proposed radiochromic film method for measuring bow tie profiles is an inexpensive (∼$100 USD + film costs), noninvasive method to measure the fan beam intensity profile in CT scanners.

  16. TU-F-18C-07: Hardware Advances for MTF Improvement in Dedicated Breast CT

    SciTech Connect (OSTI)

    Gazi, P; Burkett, G; Yang, K; Boone, J

    2014-06-15

    Purpose: In this study, we have designed and implemented a prototype dedicated breast CT system (bCT) to improve the spatial resolution characteristics, in order to improve detection of micro-calcifications. Methods: A 10.8 kW water-cooled, tungsten anode x-ray tube, running up to 240 mA at 60 kV, coupled with an x-ray generator specifically designed for this application, and 0.3 mm of added copper filter was used to generate x-ray pulses. A CsI CMOS flat panel detector with a pixel pitch of 0.075 mm in native binning mode was used. The system geometry was designed in a way to achieve an FOV on par with similar bCT prototypes, resulting in a magnification factor of 1.39. A 0.013 mm tungsten wire was used to generate point spread functions. Multiple scans were performed with different numbers of projections, different reconstruction kernel sizes and different reconstruction filters to study the effects of each parameter on MTF. The resulting MTFs were then evaluated quantitatively using the generated PFSs. Duplicate scans with the same parameters were performed on two other dedicated breast CT systems to compare the performance of the new prototype. Results: The results of the MTF experiments demonstrate a significant improvement in the spatial resolution characteristics. In the new prototype, using the pulsed x-ray source results in a restoration of the azimuthal MTF degradation, due to motion blurring previously seen in other bCT systems. Moreover, employing the higher resolution x-ray detector considerably improves the MTF. The MTF at 10% of the new system is at 3.5 1/mm, a factor of 4.36 greater than an earlier bCT scanner. Conclusion: The MTF analysis of the new prototype bCT shows that using the new hardware and control results in a significant improvement in visualization of finer detail. This suggests that the visualization of micro-calcifications will be significantly improved.

  17. SU-E-I-58: Detecting Tumors with Extremely Low Contrast in CT Images

    SciTech Connect (OSTI)

    Sheng, K; Gou, S; Kupelian, P; Steiberg, M; Low, D

    2014-06-01

    Purpose: Tumors such as the prostate focal lesions and the brain metastases have extremely low CT contrast and MRI is usually used for target delineation. The target contours are propagated to the CT for treatment planning and patient positioning. We have employed an advanced denoising method eliminating the noise and allow magnification of subtle contrast of these focal lesions on CT. Methods: Five prostate and two brain metastasis patients with MRI T2, diffusion or dynamic contrast enhanced (DCE) images confirmed focal lesions were included. One brain patients had 5 metastases. A block matching 3D (BM3D) algorithm was adapted to reduce the noise of kVCT images used for treatment planning. The gray-level range of the resultant images was narrowed to magnify the tumor-normal tissue contrast. Results: For the prostate patients, denoised kVCT images showed focal regions at 5, 8,11-1, 2, and 8–10 oclock for the 5 patients, this is highly consistent to the radiologist confirmed focal lesions based on MRI at 5, 7, 11-1, 2 and 8–10 oclock in the axial plane. These CT focal regions matched well with the MRI focal lesions in the cranio-caudal position. The average increase in density compared to background prostate glands was 0.86%, which corresponds to ∼50% increase in cellularity and is lower than the average CT noise level of 2.4%. For the brain patients, denoised kVCT showed 5/6 metastases. The high CT-density region of a metastasis is 2-mm off from its corresponding elevated MRI perfusion center. Overall the detecting sensitivity was 91%. Conclusion: It has been preliminarily demonstrated that the higher tumor cellularity can be detected using kVCT. The low contrast-to-noise information requires advanced denoising to reveal. The finding is significant to radiotherapy by providing an additional tool to locate focal lesions for confirming MRI-CT registration and providing a highly accessible outcome assessment tool.

  18. Statistical model based iterative reconstruction (MBIR) in clinical CT systems: Experimental assessment of noise performance

    SciTech Connect (OSTI)

    Li, Ke; Tang, Jie; Chen, Guang-Hong

    2014-04-15

    Purpose: To reduce radiation dose in CT imaging, the statistical model based iterative reconstruction (MBIR) method has been introduced for clinical use. Based on the principle of MBIR and its nonlinear nature, the noise performance of MBIR is expected to be different from that of the well-understood filtered backprojection (FBP) reconstruction method. The purpose of this work is to experimentally assess the unique noise characteristics of MBIR using a state-of-the-art clinical CT system. Methods: Three physical phantoms, including a water cylinder and two pediatric head phantoms, were scanned in axial scanning mode using a 64-slice CT scanner (Discovery CT750 HD, GE Healthcare, Waukesha, WI) at seven different mAs levels (5, 12.5, 25, 50, 100, 200, 300). At each mAs level, each phantom was repeatedly scanned 50 times to generate an image ensemble for noise analysis. Both the FBP method with a standard kernel and the MBIR method (Veo{sup }, GE Healthcare, Waukesha, WI) were used for CT image reconstruction. Three-dimensional (3D) noise power spectrum (NPS), two-dimensional (2D) NPS, and zero-dimensional NPS (noise variance) were assessed both globally and locally. Noise magnitude, noise spatial correlation, noise spatial uniformity and their dose dependence were examined for the two reconstruction methods. Results: (1) At each dose level and at each frequency, the magnitude of the NPS of MBIR was smaller than that of FBP. (2) While the shape of the NPS of FBP was dose-independent, the shape of the NPS of MBIR was strongly dose-dependent; lower dose lead to a redder NPS with a lower mean frequency value. (3) The noise standard deviation (?) of MBIR and dose were found to be related through a power law of ????(dose){sup ??} with the component ? ? 0.25, which violated the classical ????(dose){sup ?0.5} power law in FBP. (4) With MBIR, noise reduction was most prominent for thin image slices. (5) MBIR lead to better noise spatial uniformity when compared with FBP

  19. Clinical evaluation of the iterative metal artifact reduction algorithm for CT simulation in radiotherapy

    SciTech Connect (OSTI)

    Axente, Marian; Von Eyben, Rie; Hristov, Dimitre; Paidi, Ajay; Bani-Hashemi, Ali; Zeng, Chuan; Krauss, Andreas

    2015-03-15

    Purpose: To clinically evaluate an iterative metal artifact reduction (IMAR) algorithm prototype in the radiation oncology clinic setting by testing for accuracy in CT number retrieval, relative dosimetric changes in regions affected by artifacts, and improvements in anatomical and shape conspicuity of corrected images. Methods: A phantom with known material inserts was scanned in the presence/absence of metal with different configurations of placement and sizes. The relative change in CT numbers from the reference data (CT with no metal) was analyzed. The CT studies were also used for dosimetric tests where dose distributions from both photon and proton beams were calculated. Dose differences and gamma analysis were calculated to quantify the relative changes between doses calculated on the different CT studies. Data from eight patients (all different treatment sites) were also used to quantify the differences between dose distributions before and after correction with IMAR, with no reference standard. A ranking experiment was also conducted to analyze the relative confidence of physicians delineating anatomy in the near vicinity of the metal implants. Results: IMAR corrected images proved to accurately retrieve CT numbers in the phantom study, independent of metal insert configuration, size of the metal, and acquisition energy. For plastic water, the mean difference between corrected images and reference images was −1.3 HU across all scenarios (N = 37) with a 90% confidence interval of [−2.4, −0.2] HU. While deviations were relatively higher in images with more metal content, IMAR was able to effectively correct the CT numbers independent of the quantity of metal. Residual errors in the CT numbers as well as some induced by the correction algorithm were found in the IMAR corrected images. However, the dose distributions calculated on IMAR corrected images were closer to the reference data in phantom studies. Relative spatial difference in the dose

  20. Validation of a deformable image registration technique for cone beam CT-based dose verification

    SciTech Connect (OSTI)

    Moteabbed, M. Sharp, G. C.; Wang, Y.; Trofimov, A.; Efstathiou, J. A.; Lu, H.-M.

    2015-01-15

    Purpose: As radiation therapy evolves toward more adaptive techniques, image guidance plays an increasingly important role, not only in patient setup but also in monitoring the delivered dose and adapting the treatment to patient changes. This study aimed to validate a method for evaluation of delivered intensity modulated radiotherapy (IMRT) dose based on multimodal deformable image registration (DIR) for prostate treatments. Methods: A pelvic phantom was scanned with CT and cone-beam computed tomography (CBCT). Both images were digitally deformed using two realistic patient-based deformation fields. The original CT was then registered to the deformed CBCT resulting in a secondary deformed CT. The registration quality was assessed as the ability of the DIR method to recover the artificially induced deformations. The primary and secondary deformed CT images as well as vector fields were compared to evaluate the efficacy of the registration method and it’s suitability to be used for dose calculation. PLASTIMATCH, a free and open source software was used for deformable image registration. A B-spline algorithm with optimized parameters was used to achieve the best registration quality. Geometric image evaluation was performed through voxel-based Hounsfield unit (HU) and vector field comparison. For dosimetric evaluation, IMRT treatment plans were created and optimized on the original CT image and recomputed on the two warped images to be compared. The dose volume histograms were compared for the warped structures that were identical in both warped images. This procedure was repeated for the phantom with full, half full, and empty bladder. Results: The results indicated mean HU differences of up to 120 between registered and ground-truth deformed CT images. However, when the CBCT intensities were calibrated using a region of interest (ROI)-based calibration curve, these differences were reduced by up to 60%. Similarly, the mean differences in average vector field

  1. SU-E-P-11: Comparison of Image Quality and Radiation Dose Between Different Scanner System in Routine Abdomen CT

    SciTech Connect (OSTI)

    Liao, S; Wang, Y; Weng, H

    2015-06-15

    Purpose To evaluate image quality and radiation dose of routine abdomen computed tomography exam with the automatic current modulation technique (ATCM) performed in two different brand 64-slice CT scanners in our site. Materials and Methods A retrospective review of routine abdomen CT exam performed with two scanners; scanner A and scanner B in our site. To calculate standard deviation of the portal hepatic level with a region of interest of 12.5 mm x 12.5mm represented to the image noise. The radiation dose was obtained from CT DICOM image information. Using Computed tomography dose index volume (CTDIv) to represented CT radiation dose. The patient data in this study were with normal weight (about 65–75 Kg). Results The standard deviation of Scanner A was smaller than scanner B, the scanner A might with better image quality than scanner B. On the other hand, the radiation dose of scanner A was higher than scanner B(about higher 50–60%) with ATCM. Both of them, the radiation dose was under diagnostic reference level. Conclusion The ATCM systems in modern CT scanners can contribute a significant reduction in radiation dose to the patient. But the reduction by ATCM systems from different CT scanner manufacturers has slightly variation. Whatever CT scanner we use, it is necessary to find the acceptable threshold of image quality with the minimum possible radiation exposure to the patient in agreement with the ALARA principle.

  2. SU-E-I-21: Dosimetric Characterization and Image Quality Evaluation of the AIRO Mobile CT Scanner

    SciTech Connect (OSTI)

    Weir, V; Zhang, J; Bruner, A

    2015-06-15

    Purpose: The AIRO Mobile CT system was recently introduced which overcomes the limitations from existing CT, CT fluoroscopy, and intraoperative O-arm. With an integrated table and a large diameter bore, the system is suitable for cranial, spine and trauma procedures, making it a highly versatile intraoperative imaging system. This study is to investigate radiation dose and image quality of the AIRO and compared with those from a routine CT scanner. Methods: Radiation dose was measured using a conventional 100mm pencil ionization chamber and CT polymethylmetacrylate (PMMA) body and head phantoms. Image quality was evaluated with a CATPHAN 500 phantom. Spatial resolution, low contrast resolution (CNR), Modulation Transfer Function (MTF), and Normalized Noise Power Spectrum (NNPS) were analyzed. Results: Under identical technique conditions, radiation dose (mGy/mAs) from the AIRO mobile CT system (AIRO) is higher than that from a 64 slice CT scanner. MTFs show that both Soft and Standard filters of the AIRO system lost resolution quickly compared to the Sensation 64 slice CT. With the Standard kernel, the spatial resolutions of the AIRO system are 3lp/cm and 4lp/cm for the body and head FOVs, respectively. NNPSs show low frequency noise due to ring-like artifacts. Due to a higher dose in terms of mGy/mAs at both head and body FOV, CNR of the AIRO system is higher than that of the Siemens scanner. However detectability of the low contrast objects is poorer in the AIRO due to the presence of ring artifacts in the location of the targets. Conclusion: For image guided surgery applications, the AIRO has some advantages over a routine CT scanner due to its versatility, large bore size, and acceptable image quality. Our evaluation of the physical performance helps its future improvements.

  3. Reports

    Office of Legacy Management (LM)

    aehsed herewith ia Coaprehenaive Survey of USBEC mtp, Lewebldinge ad Grn&-owned Bpipment under SC & COntraCtCW'S COntrOl, as requested in AEC BULLETIN No. 48 dated April 26,...

  4. SU-E-I-32: Benchmarking Head CT Doses: A Pooled Vs. Protocol Specific Analysis of Radiation Doses in Adult Head CT Examinations

    SciTech Connect (OSTI)

    Fujii, K; Bostani, M; Cagnon, C; McNitt-Gray, M

    2015-06-15

    Purpose: The aim of this study was to collect CT dose index data from adult head exams to establish benchmarks based on either: (a) values pooled from all head exams or (b) values for specific protocols. One part of this was to investigate differences in scan frequency and CT dose index data for inpatients versus outpatients. Methods: We collected CT dose index data (CTDIvol) from adult head CT examinations performed at our medical facilities from Jan 1st to Dec 31th, 2014. Four of these scanners were used for inpatients, the other five were used for outpatients. All scanners used Tube Current Modulation. We used X-ray dose management software to mine dose index data and evaluate CTDIvol for 15807 inpatients and 4263 outpatients undergoing Routine Brain, Sinus, Facial/Mandible, Temporal Bone, CTA Brain and CTA Brain-Neck protocols, and combined across all protocols. Results: For inpatients, Routine Brain series represented 84% of total scans performed. For outpatients, Sinus scans represented the largest fraction (36%). The CTDIvol (mean ± SD) across all head protocols was 39 ± 30 mGy (min-max: 3.3–540 mGy). The CTDIvol for Routine Brain was 51 ± 6.2 mGy (min-max: 36–84 mGy). The values for Sinus were 24 ± 3.2 mGy (min-max: 13–44 mGy) and for Facial/Mandible were 22 ± 4.3 mGy (min-max: 14–46 mGy). The mean CTDIvol for inpatients and outpatients was similar across protocols with one exception (CTA Brain-Neck). Conclusion: There is substantial dose variation when results from all protocols are pooled together; this is primarily a function of the differences in technical factors of the protocols themselves. When protocols are analyzed separately, there is much less variability. While analyzing pooled data affords some utility, reviewing protocols segregated by clinical indication provides greater opportunity for optimization and establishing useful benchmarks.

  5. Estimation of the weighted CTDI{sub {infinity}} for multislice CT examinations

    SciTech Connect (OSTI)

    Li Xinhua; Zhang Da; Liu, Bob

    2012-02-15

    Purpose: The aim of this study was to examine the variations of CT dose index (CTDI) efficiencies, {epsilon}(CTDI{sub 100})=CTDI{sub 100}/CTDI{sub {infinity}}, with bowtie filters and CT scanner types. Methods: This was an extension of our previous study [Li, Zhang, and Liu, Phys. Med. Biol. 56, 5789-5803 (2011)]. A validated Monte Carlo program was used to calculate {epsilon}(CTDI{sub 100}) on a Siemens Somatom Definition scanner. The {epsilon}(CTDI{sub 100}) dependencies on tube voltages and beam widths were tested in previous studies. The influences of different bowtie filters and CT scanner types were examined in this work. The authors tested the variations of {epsilon}(CTDI{sub 100}) with bowtie filters on the Siemens Definition scanner. The authors also analyzed the published CTDI measurements of four independent studies on five scanners of four models from three manufacturers. Results: On the Siemens Definition scanner, the difference in {epsilon}(CTDI{sub W}) between using the head and body bowtie filters was 2.5% (maximum) in the CT scans of the 32-cm phantom, and 1.7% (maximum) in the CT scans of the 16-cm phantom. Compared with CTDI{sub W}, the weighted CTDI{sub {infinity}} increased by 30.5% (on average) in the 32-cm phantom, and by 20.0% (on average) in the 16-cm phantom. These results were approximately the same for 80-140 kV and 1-40 mm beam widths (4.2% maximum deviation). The differences in {epsilon}(CTDI{sub 100}) between the simulations and the direct measurements of four previous studies were 1.3%-5.0% at the center/periphery of the 16-cm/32-cm phantom (on average). Conclusions: Compared with CTDI{sub vol}, the equilibrium dose for large scan lengths is 30.5% higher in the 32-cm phantom, and is 20.0% higher in the 16-cm phantom. The relative increases are practically independent of tube voltages (80-140 kV), beam widths (up to 4 cm), and the CT scanners covered in this study.

  6. Correlation between human observer performance and model observer performance in differential phase contrast CT

    SciTech Connect (OSTI)

    Li, Ke; Garrett, John; Chen, Guang-Hong

    2013-11-15

    Purpose: With the recently expanding interest and developments in x-ray differential phase contrast CT (DPC-CT), the evaluation of its task-specific detection performance and comparison with the corresponding absorption CT under a given radiation dose constraint become increasingly important. Mathematical model observers are often used to quantify the performance of imaging systems, but their correlations with actual human observers need to be confirmed for each new imaging method. This work is an investigation of the effects of stochastic DPC-CT noise on the correlation of detection performance between model and human observers with signal-known-exactly (SKE) detection tasks.Methods: The detectabilities of different objects (five disks with different diameters and two breast lesion masses) embedded in an experimental DPC-CT noise background were assessed using both model and human observers. The detectability of the disk and lesion signals was then measured using five types of model observers including the prewhitening ideal observer, the nonprewhitening (NPW) observer, the nonprewhitening observer with eye filter and internal noise (NPWEi), the prewhitening observer with eye filter and internal noise (PWEi), and the channelized Hotelling observer (CHO). The same objects were also evaluated by four human observers using the two-alternative forced choice method. The results from the model observer experiment were quantitatively compared to the human observer results to assess the correlation between the two techniques.Results: The contrast-to-detail (CD) curve generated by the human observers for the disk-detection experiments shows that the required contrast to detect a disk is inversely proportional to the square root of the disk size. Based on the CD curves, the ideal and NPW observers tend to systematically overestimate the performance of the human observers. The NPWEi and PWEi observers did not predict human performance well either, as the slopes of their CD

  7. Predicting adenocarcinoma recurrence using computational texture models of nodule components in lung CT

    SciTech Connect (OSTI)

    Depeursinge, Adrien; Yanagawa, Masahiro; Leung, Ann N.; Rubin, Daniel L.

    2015-04-15

    Purpose: To investigate the importance of presurgical computed tomography (CT) intensity and texture information from ground-glass opacities (GGO) and solid nodule components for the prediction of adenocarcinoma recurrence. Methods: For this study, 101 patients with surgically resected stage I adenocarcinoma were selected. During the follow-up period, 17 patients had disease recurrence with six associated cancer-related deaths. GGO and solid tumor components were delineated on presurgical CT scans by a radiologist. Computational texture models of GGO and solid regions were built using linear combinations of steerable Riesz wavelets learned with linear support vector machines (SVMs). Unlike other traditional texture attributes, the proposed texture models are designed to encode local image scales and directions that are specific to GGO and solid tissue. The responses of the locally steered models were used as texture attributes and compared to the responses of unaligned Riesz wavelets. The texture attributes were combined with CT intensities to predict tumor recurrence and patient hazard according to disease-free survival (DFS) time. Two families of predictive models were compared: LASSO and SVMs, and their survival counterparts: Cox-LASSO and survival SVMs. Results: The best-performing predictive model of patient hazard was associated with a concordance index (C-index) of 0.81 ± 0.02 and was based on the combination of the steered models and CT intensities with survival SVMs. The same feature group and the LASSO model yielded the highest area under the receiver operating characteristic curve (AUC) of 0.8 ± 0.01 for predicting tumor recurrence, although no statistically significant difference was found when compared to using intensity features solely. For all models, the performance was found to be significantly higher when image attributes were based on the solid components solely versus using the entire tumors (p < 3.08 × 10{sup −5}). Conclusions: This study

  8. Adaptive nonlocal means filtering based on local noise level for CT denoising

    SciTech Connect (OSTI)

    Li, Zhoubo; Trzasko, Joshua D.; Lake, David S.; Blezek, Daniel J.; Manduca, Armando; Yu, Lifeng; Fletcher, Joel G.; McCollough, Cynthia H.

    2014-01-15

    Purpose: To develop and evaluate an image-domain noise reduction method based on a modified nonlocal means (NLM) algorithm that is adaptive to local noise level of CT images and to implement this method in a time frame consistent with clinical workflow. Methods: A computationally efficient technique for local noise estimation directly from CT images was developed. A forward projection, based on a 2D fan-beam approximation, was used to generate the projection data, with a noise model incorporating the effects of the bowtie filter and automatic exposure control. The noise propagation from projection data to images was analytically derived. The analytical noise map was validated using repeated scans of a phantom. A 3D NLM denoising algorithm was modified to adapt its denoising strength locally based on this noise map. The performance of this adaptive NLM filter was evaluated in phantom studies in terms of in-plane and cross-plane high-contrast spatial resolution, noise power spectrum (NPS), subjective low-contrast spatial resolution using the American College of Radiology (ACR) accreditation phantom, and objective low-contrast spatial resolution using a channelized Hotelling model observer (CHO). Graphical processing units (GPU) implementation of this noise map calculation and the adaptive NLM filtering were developed to meet demands of clinical workflow. Adaptive NLM was piloted on lower dose scans in clinical practice. Results: The local noise level estimation matches the noise distribution determined from multiple repetitive scans of a phantom, demonstrated by small variations in the ratio map between the analytical noise map and the one calculated from repeated scans. The phantom studies demonstrated that the adaptive NLM filter can reduce noise substantially without degrading the high-contrast spatial resolution, as illustrated by modulation transfer function and slice sensitivity profile results. The NPS results show that adaptive NLM denoising preserves the

  9. Novel methods of measuring single scan dose profiles and cumulative dose in CT

    SciTech Connect (OSTI)

    Nakonechny, K.D.; Fallone, B.G.; Rathee, S.

    2005-01-01

    Computed tomography dose index (CTDI) is a conventional indicator of the patient dose in CT studies. It is measured as the integration of the longitudinal single scan dose profile (SSDP) by using a 100-mm-long pencil ionization chamber and a single axial scan. However, the assumption that most of the SSDP is contained within the chamber length may not be valid even for thin slices. We have measured the SSDPs for several slice widths on two CT scanners using a PTW diamond detector placed in a 300 mmx200 mmx300 mm water-equivalent plastic phantom. One SSDP was also measured using lithium fluoride (LiF) TLDs and an IC-10 small volume ion chamber, verifying the general shape of the SSDP measured using the diamond detector. Standard cylindrical PMMA CT phantoms (140 mm length) were also used to qualitatively study the effects of phantom shape, length, and composition on the measured SSDP. The SSDPs measured with the diamond detector in the water-equivalent phantom were numerically integrated to calculate the relative accumulated dose D{sub L}(0){sub calc} at the center of various scan lengths L. D{sub L}(0){sub calc} reached an equilibrium value for L>300 mm, suggesting the need for phantoms longer than standard CT dose phantoms. We have also measured the absolute accumulated dose using an IC-10 small volume ion chamber, D{sub L}(0){sub SV}, at three points in the phantom cross section for several beamwidths and scan lengths. For one CT system, these measurements were made in both axial and helical scanning modes. The absolute CTDI{sub 100}, measured with a 102 mm active length pencil chamber, were within 4% of D{sub L}(0){sub SV} measured with the small volume ion chamber for L{approx_equal}100 mm suggesting that nonpencil chambers can be successfully used for CT dosimetry. For nominal beam widths ranging from 3 to 20 mm and for L{approx_equal}250 mm, D{sub L}(0){sub SV} values at the center of the water-equivalent phantom's elliptic cross section were approximately 25

  10. Cholecystokinin-Assisted Hydrodissection of the Gallbladder Fossa during FDG PET/CT-guided Liver Ablation

    SciTech Connect (OSTI)

    Tewari, Sanjit O.; Petre, Elena N.; Osborne, Joseph; Sofocleous, Constantinos T.

    2013-12-15

    A 68-year-old female with colorectal cancer developed a metachronous isolated fluorodeoxyglucose-avid (FDG-avid) segment 5/6 gallbladder fossa hepatic lesion and was referred for percutaneous ablation. Pre-procedure computed tomography (CT) images demonstrated a distended gallbladder abutting the segment 5/6 hepatic metastasis. In order to perform ablation with clear margins and avoid direct puncture and aspiration of the gallbladder, cholecystokinin was administered intravenously to stimulate gallbladder contraction before hydrodissection. Subsequently, the lesion was ablated successfully with sufficient margins, of greater than 1.0 cm, using microwave with ultrasound and FDG PET/CT guidance. The patient tolerated the procedure very well and was discharged home the next day.

  11. HIA 2015 DOE Zero Energy Ready Home Case Study: Glastonbury Housesmith, Hickory Drive, South Glastonbury, CT

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Glastonbury Housesmith Hickory Drive South Glastonbury, CT DOE ZERO ENERGY READY HOME(tm) The U.S. Department of Energy invites home builders across the country to meet the extraordinary levels of excellence and quality specified in DOE's Zero Energy Ready Home program (formerly known as Challenge Home). Every DOE Zero Energy Ready Home starts with ENERGY STAR Certified Homes Version 3.0 for an energy-efficient home built on a solid foundation of building science research. Advanced technologies

  12. SU-E-P-03: Implementing a Low Dose Lung Screening CT Program Meeting Regulatory Requirements

    SciTech Connect (OSTI)

    LaFrance, M; Marsh, S; O'Donnell, G

    2014-06-01

    Purpose: To provide information pertaining to IROC Houston QA Center's (RPC) credentialing process for institutions participating in NCI-sponsored clinical trials. Purpose: Provide guidance to the Radiology Departments with the intent of implementing a Low Dose CT Screening Program using different CT Scanners with multiple techniques within the framework of the required state regulations. Method: State Requirements for the purpose of implementing a Low Dose CT Lung Protocol required working with the Radiology and Pulmonary Department in setting up a Low Dose Screening Protocol designed to reduce the radiation burden to the patients enrolled. Radiation dose measurements (CTDIvol) for various CT manufacturers (Siemens16, Siemens 64, Philips 64, and Neusoft128) for three different weight based protocols. All scans were reviewed by the Radiologist. Prior to starting a low dose lung screening protocol, information had to be submitted to the state for approval. Performing a Healing Arts protocol requires extensive information. This not only includes name and address of the applicant but a detailed description of the disease, the x-ray examination and the population to be examined. The unit had to be tested by a qualified expert using the technique charts. The credentials of all the operators, the supervisors and the Radiologists had to be submitted to the state. Results: All the appropriate documentation was sent to the state for review. The measured results between the Low Dose Protocol versus the default Adult Chest Protocol showed that there was a dose reduction of 65% for small (100-150 lb.) patient, 75% for the Medium patient (151-250 lbs.), and a 55% reduction for the Large patient ( over 250 lbs.). Conclusion: Measured results indicated that the Low Dose Protocol indeed lowered the screening patient's radiation dose and the institution was able to submit the protocol to the State's regulators.

  13. Recent Progress Validating the HADES Model of LLNL's HEAF MicroCT Measurements

    SciTech Connect (OSTI)

    White, W. T.; Bond, K. C.; Lennox, K. P.; Aufderheide, M. B.; Seetho, I. M.; Roberson, G. P.

    2014-07-17

    This report compares recent HADES calculations of x-ray linear attenuation coefficients to previous MicroCT measurements made at Lawrence Livermore National Laboratory’s High Energy Applications Facility (HEAF). The chief objective is to investigate what impact recent changes in HADES modeling have on validation results. We find that these changes have no obvious effect on the overall accuracy of the model. Detailed comparisons between recent and previous results are presented.

  14. DOE Zero Ready Home Case Study: Brookside Development, Singer Village, Derby, CT

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Brookside Development Singer Village Derby, CT DOE ZERO ENERGY READY HOME(tm) The U.S. Department of Energy invites home builders across the country to meet the extraordinary levels of excellence and quality specified in DOE's Zero Energy Ready Home program (formerly known as Challenge Home). Every DOE Zero Energy Ready Home starts with ENERGY STAR Certified Homes Version 3.0 for an energy-efficient home built on a solid foundation of building science research. Advanced technologies are designed

  15. STATE OF OHIO, IN THE UNITED STATES DISTRICT FOR THE .SOUTHERN DIS~CT OF

    Office of Environmental Management (EM)

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  16. GPU-accelerated regularized iterative reconstruction for few-view cone beam CT

    SciTech Connect (OSTI)

    Matenine, Dmitri; Goussard, Yves

    2015-04-15

    Purpose: The present work proposes an iterative reconstruction technique designed for x-ray transmission computed tomography (CT). The main objective is to provide a model-based solution to the cone-beam CT reconstruction problem, yielding accurate low-dose images via few-views acquisitions in clinically acceptable time frames. Methods: The proposed technique combines a modified ordered subsets convex (OSC) algorithm and the total variation minimization (TV) regularization technique and is called OSC-TV. The number of subsets of each OSC iteration follows a reduction pattern in order to ensure the best performance of the regularization method. Considering the high computational cost of the algorithm, it is implemented on a graphics processing unit, using parallelization to accelerate computations. Results: The reconstructions were performed on computer-simulated as well as human pelvic cone-beam CT projection data and image quality was assessed. In terms of convergence and image quality, OSC-TV performs well in reconstruction of low-dose cone-beam CT data obtained via a few-view acquisition protocol. It compares favorably to the few-view TV-regularized projections onto convex sets (POCS-TV) algorithm. It also appears to be a viable alternative to full-dataset filtered backprojection. Execution times are of 1–2 min and are compatible with the typical clinical workflow for nonreal-time applications. Conclusions: Considering the image quality and execution times, this method may be useful for reconstruction of low-dose clinical acquisitions. It may be of particular benefit to patients who undergo multiple acquisitions by reducing the overall imaging radiation dose and associated risks.

  17. Dose reconstruction for real-time patient-specific dose estimation in CT

    SciTech Connect (OSTI)

    De Man, Bruno Yin, Zhye; Wu, Mingye; FitzGerald, Paul; Kalra, Mannudeep

    2015-05-15

    Purpose: Many recent computed tomography (CT) dose reduction approaches belong to one of three categories: statistical reconstruction algorithms, efficient x-ray detectors, and optimized CT acquisition schemes with precise control over the x-ray distribution. The latter category could greatly benefit from fast and accurate methods for dose estimation, which would enable real-time patient-specific protocol optimization. Methods: The authors present a new method for volumetrically reconstructing absorbed dose on a per-voxel basis, directly from the actual CT images. The authors’ specific implementation combines a distance-driven pencil-beam approach to model the first-order x-ray interactions with a set of Gaussian convolution kernels to model the higher-order x-ray interactions. The authors performed a number of 3D simulation experiments comparing the proposed method to a Monte Carlo based ground truth. Results: The authors’ results indicate that the proposed approach offers a good trade-off between accuracy and computational efficiency. The images show a good qualitative correspondence to Monte Carlo estimates. Preliminary quantitative results show errors below 10%, except in bone regions, where the authors see a bigger model mismatch. The computational complexity is similar to that of a low-resolution filtered-backprojection algorithm. Conclusions: The authors present a method for analytic dose reconstruction in CT, similar to the techniques used in radiation therapy planning with megavoltage energies. Future work will include refinements of the proposed method to improve the accuracy as well as a more extensive validation study. The proposed method is not intended to replace methods that track individual x-ray photons, but the authors expect that it may prove useful in applications where real-time patient-specific dose estimation is required.

  18. SU-D-BRA-05: Toward Understanding the Robustness of Radiomics Features in CT

    SciTech Connect (OSTI)

    Mackin, D; Zhang, L; Yang, J; Jones, A; Court, L; Fave, X; Fried, D; Taylor, B; Rodriguez-Rivera, E; Dodge, C

    2015-06-15

    Purpose: To gauge the impact of inter-scanner variability on radiomics features in computed tomography (CT). Methods: We compared the radiomics features calculated for 17 scans of the specially designed Credence Cartridge Radiomics (CCR) phantom with those calculated for 20 scans of non–small cell lung cancer (NSCLC) tumors. The scans were acquired at four medical centers using General Electric, Philips, Siemens, and Toshiba CT scanners. Each center used its own routine thoracic imaging protocol. To produce a large dynamic range of radiomics feature values, the CCR phantom has 10 cartridges comprising different materials. The features studied were derived from the neighborhood gray-tone difference matrix or image intensity histogram. To quantify the significance of the inter-scanner variability, we introduced the metric “feature noise”, which compares the ratio of inter-scanner variability and inter-patient variability in decibels, positive values indicating substantial noise. We performed hierarchical clustering based to look for dependence of the features on the scan acquisition parameters. Results: For 5 of the 10 features studied, the inter-scanner variability was larger than the inter-patient variability. Of the 10 materials in the phantom, shredded rubber seemed to produce feature values most similar to those of the NSCLC tumors. The feature busyness had the greatest feature noise (14.3 dB), whereas texture strength had the least (−14.6 dB). Hierarchical clustering indicated that the features depended in part on the scanner manufacturer, image slice thickness, and pixel size. Conclusion: The variability in the values of radiomics features calculated for CT images of a radiomics phantom can be substantial relative to the variability in the values of these features calculated for CT images of NSCLC tumors. These inter-scanner differences and their effects should be carefully considered in future radiomics studies.

  19. SU-E-I-43: Pediatric CT Dose and Image Quality Optimization

    SciTech Connect (OSTI)

    Stevens, G; Singh, R

    2014-06-01

    Purpose: To design an approach to optimize radiation dose and image quality for pediatric CT imaging, and to evaluate expected performance. Methods: A methodology was designed to quantify relative image quality as a function of CT image acquisition parameters. Image contrast and image noise were used to indicate expected conspicuity of objects, and a wide-cone system was used to minimize scan time for motion avoidance. A decision framework was designed to select acquisition parameters as a weighted combination of image quality and dose. Phantom tests were used to acquire images at multiple techniques to demonstrate expected contrast, noise and dose. Anthropomorphic phantoms with contrast inserts were imaged on a 160mm CT system with tube voltage capabilities as low as 70kVp. Previously acquired clinical images were used in conjunction with simulation tools to emulate images at different tube voltages and currents to assess human observer preferences. Results: Examination of image contrast, noise, dose and tube/generator capabilities indicates a clinical task and object-size dependent optimization. Phantom experiments confirm that system modeling can be used to achieve the desired image quality and noise performance. Observer studies indicate that clinical utilization of this optimization requires a modified approach to achieve the desired performance. Conclusion: This work indicates the potential to optimize radiation dose and image quality for pediatric CT imaging. In addition, the methodology can be used in an automated parameter selection feature that can suggest techniques given a limited number of user inputs. G Stevens and R Singh are employees of GE Healthcare.

  20. CT Mapping of the Distribution of Saline During Radiofrequency Ablation with Perfusion Electrodes

    SciTech Connect (OSTI)

    Gillams, A.R. Lees, W.R.

    2005-05-15

    Purpose. During radiofrequency (RF) ablation, adjunctive saline increases the size of the ablation zone and therefore electrodes that simultaneously deliver current and saline have been developed, but the addition of saline also results in an irregular ablation zone. Our aim was to study the distribution of saline during RF ablation. Methods. Four patients were treated: 3 with liver metastases and 1 with hepatocellular carcinoma (HCC). Two different perfusion electrodes were used: a high-perfusion-rate, straight electrode (Berchtold, Germany) and a low-perfusion-rate, expandable electrode (RITA Medical Systems, USA). The saline perfusate was doped with non-ionic contrast medium to render it visible on CT and the electrical conductivity was measured. CT scans were obtained of each electrode position prior to ablation and repeated after ablation. Contrast-enhanced CT was performed 18-24 hr later to demonstrate the ablation zone. All treatments were carried out according to the manufacturer's recommended protocol. Results. The addition of a small quantity of non-ionic contrast did not alter the electrical conductivity of the saline. Contrast-doped saline extravasated beyond the tumor in all 3 patients with metastases but was limited in the patient with HCC. In some areas where saline had extravasated there was reduced enhancement on contrast-enhanced CT consistent with tissue ablation. One patient treated with the high-perfusion-rate system sustained a jejunal perforation requiring surgery. Conclusion. Saline can extravasate beyond the tumor and with the high-perfusion-rate system this resulted in an undesirable extension of the ablation zone and a complication.

  1. Prognostic Value and Reproducibility of Pretreatment CT Texture Features in Stage III Non-Small Cell Lung Cancer

    SciTech Connect (OSTI)

    Fried, David V.; Tucker, Susan L.; Zhou, Shouhao; Liao, Zhongxing; Mawlawi, Osama; Ibbott, Geoffrey; Court, Laurence E.

    2014-11-15

    Purpose: To determine whether pretreatment CT texture features can improve patient risk stratification beyond conventional prognostic factors (CPFs) in stage III non-small cell lung cancer (NSCLC). Methods and Materials: We retrospectively reviewed 91 cases with stage III NSCLC treated with definitive chemoradiation therapy. All patients underwent pretreatment diagnostic contrast enhanced computed tomography (CE-CT) followed by 4-dimensional CT (4D-CT) for treatment simulation. We used the average-CT and expiratory (T50-CT) images from the 4D-CT along with the CE-CT for texture extraction. Histogram, gradient, co-occurrence, gray tone difference, and filtration-based techniques were used for texture feature extraction. Penalized Cox regression implementing cross-validation was used for covariate selection and modeling. Models incorporating texture features from the 33 image types and CPFs were compared to those with models incorporating CPFs alone for overall survival (OS), local-regional control (LRC), and freedom from distant metastases (FFDM). Predictive Kaplan-Meier curves were generated using leave-one-out cross-validation. Patients were stratified based on whether their predicted outcome was above or below the median. Reproducibility of texture features was evaluated using test-retest scans from independent patients and quantified using concordance correlation coefficients (CCC). We compared models incorporating the reproducibility seen on test-retest scans to our original models and determined the classification reproducibility. Results: Models incorporating both texture features and CPFs demonstrated a significant improvement in risk stratification compared to models using CPFs alone for OS (P=.046), LRC (P=.01), and FFDM (P=.005). The average CCCs were 0.89, 0.91, and 0.67 for texture features extracted from the average-CT, T50-CT, and CE-CT, respectively. Incorporating reproducibility within our models yielded 80.4% (±3.7% SD), 78.3% (±4.0% SD), and 78

  2. Renal Sympathetic Denervation by CT-scan-Guided Periarterial Ethanol Injection in Sheep

    SciTech Connect (OSTI)

    Firouznia, Kavous Hosseininasab, Sayed jaber; Amanpour, Saeid; Haj-Mirzaian, Arya; Miri, Roza; Muhammadnejad, Ahad; Muhammadnejad, Samad; Jalali, Amir H.; Ahmadi, Farrokhlagha; Rokni-Yazdi, Hadi

    2015-08-15

    BackgroundRenal nerves are a recent target in the treatment of hypertension. Renal sympathetic denervation (RSD) is currently performed using catheter-based radiofrequency ablation (RFA) and because this method has limitations, percutaneous magnetic resonance (MR)-guided periarterial ethanol injection is a suggested alternative. However, few studies have been conducted on the effectiveness of percutaneous ethanol injection for RSD.AimTo evaluate the feasibility, efficacy, and complications of computed tomography (CT)-guided periarterial ethanol injection.MethodsEthanol (10 ml, 99.6 %) was injected around the right renal artery in six sheep under CT guidance with the left kidney serving as a control. Before and after the intervention, the sheep underwent MR imaging studies and the serum creatinine level was measured. One month after the intervention, the sheep were euthanized and norepinephrine (NE) concentration in the renal parenchyma was measured to evaluate the efficacy of the procedure. The treated tissues were also examined histopathologically to evaluate vascular, parenchymal, and neural injury.ResultsThe right kidney parenchymal NE concentration decreased significantly compared with the left kidney after intervention (average reduction: 40 %, P = 0.0016). Histologic examination revealed apparent denervation with no other vascular or parenchymal injuries observed in the histological and imaging studies.ConclusionEffective and feasible RSD was achieved using CT-guided periarterial ethanol injection. This technique may be a potential alternative to catheter-based RFA in the treatment of hypertension.

  3. CT-Guided Interventions Using a Free-Hand, Optical Tracking System: Initial Clinical Experience

    SciTech Connect (OSTI)

    Schubert, Tilman Jacob, Augustinus L.; Pansini, Michele; Liu, David; Gutzeit, Andreas; Kos, Sebastian

    2013-08-01

    PurposeThe present study was designed to evaluate the geometrical accuracy and clinical applicability of a new, free-hand, CT-guided, optical navigation system.MethodsFifteen procedures in 14 consecutive patients were retrospectively analyzed. The navigation system was applied for interventional procedures on small target lesions, in cases with long needle paths, narrow access windows, or when an out-of-plane access was expected. Mean lesion volume was 27.9 ml, and mean distance to target measured was 107.5 mm. Eleven of 15 needle trajectories were planned as out-of-plane approaches regarding the axial CT plane.ResultsNinety-one percent of the biopsies were diagnostic. All therapeutic interventions were technically successful. Targeting precision was high with a mean distance of the needle tip from planned target of 1.98 mm. Mean intervention time was 1:12 h. A statistically significant correlation between angular needle deviation and intervention time (p = 0.007), respiratory movement of the target (p = 0.008), and body mass index (p = 0.02) was detected. None of the evaluated parameters correlated significantly with the distance from the needle tip to the planned target.ConclusionsThe application of a navigation system for complex CT-guided procedures provided safe and effective targeting within a reasonable intervention time in our series.

  4. Design and performance of a respiratory amplitude gating device for PET/CT imaging

    SciTech Connect (OSTI)

    Chang Guoping; Chang Tingting; Clark, John W. Jr.; Mawlawi, Osama R.

    2010-04-15

    Purpose: Recently, the authors proposed a free-breathing amplitude gating (FBAG) technique for PET/CT scanners. The implementation of this technique required specialized hardware and software components that were specifically designed to interface with commercial respiratory gating devices to generate the necessary triggers required for the FBAG technique. The objective of this technical note is to introduce an in-house device that integrates all the necessary hardware and software components as well as tracks the patient's respiratory motion to realize amplitude gating on PET/CT scanners. Methods: The in-house device is composed of a piezoelectric transducer coupled to a data-acquisition system in order to monitor the respiratory waveform. A LABVIEW program was designed to control the data-acquisition device and inject triggers into the PET list stream whenever the detected respiratory amplitude crossed a predetermined amplitude range. A timer was also programmed to stop the scan when the accumulated time within the selected amplitude range reached a user-set interval. This device was tested using a volunteer and a phantom study. Results: The results from the volunteer and phantom studies showed that the in-house device can detect similar respiratory signals as commercially available respiratory gating systems and is able to generate the necessary triggers to suppress respiratory motion artifacts. Conclusions: The proposed in-house device can be used to implement the FBAG technique in current PET/CT scanners.

  5. Material Science Image Analysis using Quant-CT in ImageJ

    SciTech Connect (OSTI)

    Ushizima, Daniela M.; Bianchi, Andrea G. C.; DeBianchi, Christina; Bethel, E. Wes

    2015-01-05

    We introduce a computational analysis workflow to access properties of solid objects using nondestructive imaging techniques that rely on X-ray imaging. The goal is to process and quantify structures from material science sample cross sections. The algorithms can differentiate the porous media (high density material) from the void (background, low density media) using a Boolean classifier, so that we can extract features, such as volume, surface area, granularity spectrum, porosity, among others. Our workflow, Quant-CT, leverages several algorithms from ImageJ, such as statistical region merging and 3D object counter. It also includes schemes for bilateral filtering that use a 3D kernel, for parallel processing of sub-stacks, and for handling over-segmentation using histogram similarities. The Quant-CT supports fast user interaction, providing the ability for the user to train the algorithm via subsamples to feed its core algorithms with automated parameterization. Quant-CT plugin is currently available for testing by personnel at the Advanced Light Source and Earth Sciences Divisions and Energy Frontier Research Center (EFRC), LBNL, as part of their research on porous materials. The goal is to understand the processes in fluid-rock systems for the geologic sequestration of CO2, and to develop technology for the safe storage of CO2 in deep subsurface rock formations. We describe our implementation, and demonstrate our plugin on porous material images. This paper targets end-users, with relevant information for developers to extend its current capabilities.

  6. CT based computerized identification and analysis of human airways: A review

    SciTech Connect (OSTI)

    Pu Jiantao; Gu Suicheng; Liu Shusen; Zhu Shaocheng; Wilson, David; Siegfried, Jill M.; Gur, David

    2012-05-15

    As one of the most prevalent chronic disorders, airway disease is a major cause of morbidity and mortality worldwide. In order to understand its underlying mechanisms and to enable assessment of therapeutic efficacy of a variety of possible interventions, noninvasive investigation of the airways in a large number of subjects is of great research interest. Due to its high resolution in temporal and spatial domains, computed tomography (CT) has been widely used in clinical practices for studying the normal and abnormal manifestations of lung diseases, albeit there is a need to clearly demonstrate the benefits in light of the cost and radiation dose associated with CT examinations performed for the purpose of airway analysis. Whereas a single CT examination consists of a large number of images, manually identifying airway morphological characteristics and computing features to enable thorough investigations of airway and other lung diseases is very time-consuming and susceptible to errors. Hence, automated and semiautomated computerized analysis of human airways is becoming an important research area in medical imaging. A number of computerized techniques have been developed to date for the analysis of lung airways. In this review, we present a summary of the primary methods developed for computerized analysis of human airways, including airway segmentation, airway labeling, and airway morphometry, as well as a number of computer-aided clinical applications, such as virtual bronchoscopy. Both successes and underlying limitations of these approaches are discussed, while highlighting areas that may require additional work.

  7. SU-E-J-222: Evaluation of Deformable Registration of PET/CT Images for Cervical Cancer Brachytherapy

    SciTech Connect (OSTI)

    Liao, Y; Turian, J; Templeton, A; Kiel, K; Chu, J; Kadir, T

    2014-06-01

    Purpose: PET/CT provides important functional information for radiotherapy targeting of cervical cancer. However, repeated PET/CT procedures for external beam and subsequent brachytherapy expose patients to additional radiation and are not cost effective. Our goal is to investigate the possibility of propagating PET-active volumes for brachytherapy procedures through deformable image registration (DIR) of earlier PET/CT and ultimately to minimize the number of PET/CT image sessions required. Methods: Nine cervical cancer patients each received their brachytherapy preplanning PET/CT at the end of EBRT with a Syed template in place. The planning PET/CT was acquired on the day of brachytherapy treatment with the actual applicator (Syed or Tandem and Ring) and rigidly registered. The PET/CT images were then deformably registered creating a third (deformed) image set for target prediction. Regions of interest with standardized uptake values (SUV) greater than 65% of maximum SUV were contoured as target volumes in all three sets of PET images. The predictive value of the registered images was evaluated by comparing the preplanning and deformed PET volumes with the planning PET volume using Dice's coefficient (DC) and center-of-mass (COM) displacement. Results: The average DCs were 0.12±0.14 and 0.19±0.16 for rigid and deformable predicted target volumes, respectively. The average COM displacements were 1.9±0.9 cm and 1.7±0.7 cm for rigid and deformable registration, respectively. The DCs were improved by deformable registration, however, both were lower than published data for DIR in other modalities and clinical sites. Anatomical changes caused by different brachytherapy applicators could have posed a challenge to the DIR algorithm. The physiological change from interstitial needle placement may also contribute to lower DC. Conclusion: The clinical use of DIR in PET/CT for cervical cancer brachytherapy appears to be limited by applicator choice and requires further

  8. TH-E-17A-07: Improved Cine Four-Dimensional Computed Tomography (4D CT) Acquisition and Processing Method

    SciTech Connect (OSTI)

    Castillo, S; Castillo, R; Castillo, E; Pan, T; Ibbott, G; Balter, P; Hobbs, B; Dai, J; Guerrero, T

    2014-06-15

    Purpose: Artifacts arising from the 4D CT acquisition and post-processing methods add systematic uncertainty to the treatment planning process. We propose an alternate cine 4D CT acquisition and post-processing method to consistently reduce artifacts, and explore patient parameters indicative of image quality. Methods: In an IRB-approved protocol, 18 patients with primary thoracic malignancies received a standard cine 4D CT acquisition followed by an oversampling 4D CT that doubled the number of images acquired. A second cohort of 10 patients received the clinical 4D CT plus 3 oversampling scans for intra-fraction reproducibility. The clinical acquisitions were processed by the standard phase sorting method. The oversampling acquisitions were processed using Dijkstras algorithm to optimize an artifact metric over available image data. Image quality was evaluated with a one-way mixed ANOVA model using a correlation-based artifact metric calculated from the final 4D CT image sets. Spearman correlations and a linear mixed model tested the association between breathing parameters, patient characteristics, and image quality. Results: The oversampling 4D CT scans reduced artifact presence significantly by 27% and 28%, for the first cohort and second cohort respectively. From cohort 2, the inter-replicate deviation for the oversampling method was within approximately 13% of the cross scan average at the 0.05 significance level. Artifact presence for both clinical and oversampling methods was significantly correlated with breathing period (ρ=0.407, p-value<0.032 clinical, ρ=0.296, p-value<0.041 oversampling). Artifact presence in the oversampling method was significantly correlated with amount of data acquired, (ρ=-0.335, p-value<0.02) indicating decreased artifact presence with increased breathing cycles per scan location. Conclusion: The 4D CT oversampling acquisition with optimized sorting reduced artifact presence significantly and reproducibly compared to the phase

  9. Effect of CT contrast on volumetric arc therapy planning (RapidArc and helical tomotherapy) for head and neck cancer

    SciTech Connect (OSTI)

    Liu, Alan J.; Vora, Nayana; Suh, Steve; Liu, An; Schultheiss, Timothy E.; Wong, Jeffrey Y.C.

    2015-04-01

    The objectives of the study were to evaluate the effect of intravenous contrast in the dosimetry of helical tomotherapy and RapidArc treatment for head and neck cancer and determine if it is acceptable during the computed tomography (CT) simulation to acquire only CT with contrast for treatment planning of head and neck cancer. Overall, 5 patients with head and neck cancer (4 men and 1 woman) treated on helical tomotherapy were analyzed retrospectively. For each patient, 2 consecutive CT scans were performed. The first CT set was scanned before the contrast injection and secondary study set was scanned 45 seconds after contrast. The 2 CTs were autoregistered using the same Digital Imaging and Communications in Medicine coordinates. Tomotherapy and RapidArc plans were generated on 1 CT data set and subsequently copied to the second CT set. Dose calculation was performed, and dose difference was analyzed to evaluate the influence of intravenous contrast media. The dose matrix used for comparison included mean, minimum and maximum doses of planning target volume (PTV), PTV dose coverage, and V{sub 45} {sub Gy}, V{sub 30} {sub Gy}, and V{sub 20} {sub Gy} organ doses. Treatment planning on contrasted images generally showed a lower dose to both organs and target than plans on noncontrasted images. The doses for the points of interest placed in the organs and target rarely changed more than 2% in any patient. In conclusion, treatment planning using a contrasted image had insignificant effect on the dose to the organs and targets. In our opinion, only CT with contrast needs to be acquired during the CT simulation for head and neck cancer. Dose calculations performed on contrasted images can potentially underestimate the delivery dose slightly. However, the errors of planning on a contrasted image should not affect the result in clinically significant way.

  10. SU-E-I-13: Evaluation of Metal Artifact Reduction (MAR) Software On Computed Tomography (CT) Images

    SciTech Connect (OSTI)

    Huang, V; Kohli, K

    2015-06-15

    Purpose: A new commercially available metal artifact reduction (MAR) software in computed tomography (CT) imaging was evaluated with phantoms in the presence of metals. The goal was to assess the ability of the software to restore the CT number in the vicinity of the metals without impacting the image quality. Methods: A Catphan 504 was scanned with a GE Optima RT 580 CT scanner (GE Healthcare, Milwaukee, WI) and the images were reconstructed with and without the MAR software. Both datasets were analyzed with Image Owl QA software (Image Owl Inc, Greenwich, NY). CT number sensitometry, MTF, low contrast, uniformity, noise and spatial accuracy were compared for scans with and without MAR software. In addition, an in-house made phantom was scanned with and without a stainless steel insert at three different locations. The accuracy of the CT number and metal insert dimension were investigated as well. Results: Comparisons between scans with and without MAR algorithm on the Catphan phantom demonstrate similar results for image quality. However, noise was slightly higher for the MAR algorithm. Evaluation of the CT number at various locations of the in-house made phantom was also performed. The baseline HU, obtained from the scan without metal insert, was compared to scans with the stainless steel insert at 3 different locations. The HU difference between the baseline scan versus metal scan was improved when the MAR algorithm was applied. In addition, the physical diameter of the stainless steel rod was over-estimated by the MAR algorithm by 0.9 mm. Conclusion: This work indicates with the presence of metal in CT scans, the MAR algorithm is capable of providing a more accurate CT number without compromising the overall image quality. Future work will include the dosimetric impact on the MAR algorithm.