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Title: Pediatric organ dose measurements in axial and helical multislice CT

Abstract

An anthropomorphic pediatric phantom (5-yr-old equivalent) was used to determine organ doses at specific surface and internal locations resulting from computed tomography (CT) scans. This phantom contains four different tissue-equivalent materials: Soft tissue, bone, brain, and lung. It was imaged on a 64-channel CT scanner with three head protocols (one contiguous axial scan and two helical scans [pitch=0.516 and 0.984]) and four chest protocols (one contiguous axial scan and three helical scans [pitch=0.516, 0.984, and 1.375]). Effective mA s [=(tube currentxrotation time)/pitch] was kept nearly constant at 200 effective mA s for head and 290 effective mA s for chest protocols. Dose measurements were acquired using thermoluminescent dosimeter powder in capsules placed at locations internal to the phantom and on the phantom surface. The organs of interest were the brain, both eyes, thyroid, sternum, both breasts, and both lungs. The organ dose measurements from helical scans were lower than for contiguous axial scans by 0% to 25% even after adjusting for equivalent effective mA s. There was no significant difference (p>0.05) in organ dose values between the 0.516 and 0.984 pitch values for both head and chest scans. The chest organ dose measurements obtained at a pitch of 1.375 weremore » significantly higher than the dose values obtained at the other helical pitches used for chest scans (p<0.05). This difference was attributed to the automatic selection of the large focal spot due to a higher tube current value. These findings suggest that there may be a previously unsuspected radiation dose benefit associated with the use of helical scan mode during computed tomography scanning.« less

Authors:
; ; ; ;  [1];  [2];  [2];  [2];  [2]
  1. 230 N. Kenwood Street, Apartment 211, Burbank, California 91505 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22100493
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 36; Journal Issue: 5; Other Information: (c) 2009 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; 61 RADIATION PROTECTION AND DOSIMETRY; BRAIN; CAT SCANNING; CHEST; DOSIMETRY; EYES; LUNGS; MAMMARY GLANDS; PEDIATRICS; PHANTOMS; RADIATION DOSES; SKELETON; THERMOLUMINESCENT DOSEMETERS; THYROID; TISSUE-EQUIVALENT MATERIALS

Citation Formats

McDermott, Alanna, White, R. Allen, Mc-Nitt-Gray, Mike, Angel, Erin, Cody, Dianna, Department of Bioinformatics and Computational Biology, UT MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 237, Houston, Texas 77030, Thoracic Imaging Research Group, David Geffen School of Medicine at UCLA, 924 Westwood Boulevard, Suite 650, Los Angeles, California 90095-1721, Thoracic Imaging Research Group, David Geffen School of Medicine at UCLA, 924 Westwood Boulevard, Suite 650, Los Angeles, California 90095-1721, and Department of Imaging Physics, UT MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 56, Houston, Texas 77030. Pediatric organ dose measurements in axial and helical multislice CT. United States: N. p., 2009. Web. doi:10.1118/1.3101817.
McDermott, Alanna, White, R. Allen, Mc-Nitt-Gray, Mike, Angel, Erin, Cody, Dianna, Department of Bioinformatics and Computational Biology, UT MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 237, Houston, Texas 77030, Thoracic Imaging Research Group, David Geffen School of Medicine at UCLA, 924 Westwood Boulevard, Suite 650, Los Angeles, California 90095-1721, Thoracic Imaging Research Group, David Geffen School of Medicine at UCLA, 924 Westwood Boulevard, Suite 650, Los Angeles, California 90095-1721, & Department of Imaging Physics, UT MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 56, Houston, Texas 77030. Pediatric organ dose measurements in axial and helical multislice CT. United States. doi:10.1118/1.3101817.
McDermott, Alanna, White, R. Allen, Mc-Nitt-Gray, Mike, Angel, Erin, Cody, Dianna, Department of Bioinformatics and Computational Biology, UT MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 237, Houston, Texas 77030, Thoracic Imaging Research Group, David Geffen School of Medicine at UCLA, 924 Westwood Boulevard, Suite 650, Los Angeles, California 90095-1721, Thoracic Imaging Research Group, David Geffen School of Medicine at UCLA, 924 Westwood Boulevard, Suite 650, Los Angeles, California 90095-1721, and Department of Imaging Physics, UT MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 56, Houston, Texas 77030. Fri . "Pediatric organ dose measurements in axial and helical multislice CT". United States. doi:10.1118/1.3101817.
@article{osti_22100493,
title = {Pediatric organ dose measurements in axial and helical multislice CT},
author = {McDermott, Alanna and White, R. Allen and Mc-Nitt-Gray, Mike and Angel, Erin and Cody, Dianna and Department of Bioinformatics and Computational Biology, UT MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 237, Houston, Texas 77030 and Thoracic Imaging Research Group, David Geffen School of Medicine at UCLA, 924 Westwood Boulevard, Suite 650, Los Angeles, California 90095-1721 and Thoracic Imaging Research Group, David Geffen School of Medicine at UCLA, 924 Westwood Boulevard, Suite 650, Los Angeles, California 90095-1721 and Department of Imaging Physics, UT MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 56, Houston, Texas 77030},
abstractNote = {An anthropomorphic pediatric phantom (5-yr-old equivalent) was used to determine organ doses at specific surface and internal locations resulting from computed tomography (CT) scans. This phantom contains four different tissue-equivalent materials: Soft tissue, bone, brain, and lung. It was imaged on a 64-channel CT scanner with three head protocols (one contiguous axial scan and two helical scans [pitch=0.516 and 0.984]) and four chest protocols (one contiguous axial scan and three helical scans [pitch=0.516, 0.984, and 1.375]). Effective mA s [=(tube currentxrotation time)/pitch] was kept nearly constant at 200 effective mA s for head and 290 effective mA s for chest protocols. Dose measurements were acquired using thermoluminescent dosimeter powder in capsules placed at locations internal to the phantom and on the phantom surface. The organs of interest were the brain, both eyes, thyroid, sternum, both breasts, and both lungs. The organ dose measurements from helical scans were lower than for contiguous axial scans by 0% to 25% even after adjusting for equivalent effective mA s. There was no significant difference (p>0.05) in organ dose values between the 0.516 and 0.984 pitch values for both head and chest scans. The chest organ dose measurements obtained at a pitch of 1.375 were significantly higher than the dose values obtained at the other helical pitches used for chest scans (p<0.05). This difference was attributed to the automatic selection of the large focal spot due to a higher tube current value. These findings suggest that there may be a previously unsuspected radiation dose benefit associated with the use of helical scan mode during computed tomography scanning.},
doi = {10.1118/1.3101817},
journal = {Medical Physics},
number = 5,
volume = 36,
place = {United States},
year = {Fri May 15 00:00:00 EDT 2009},
month = {Fri May 15 00:00:00 EDT 2009}
}