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Title: Dual collimation acquisition for high resolution, low noise SPECT

Abstract

This paper presents Dual Collimation (DC) imaging for SPECT as a technique to improve effective sensitivity with little loss of resolution. For some imaging tasks, DC can overcome the inherent tradeoff between resolution and sensitivity of gamma camera collimators. Simulations were used to investigate the system performance without the expense of collimator fabrication. The author implemented DC for SPECT using simulations of SPECT acquisition using two collimated gamma cameras. Projection data are acquired using two collimators simultaneously: a high sensitivity (HiSen) collimator and a high resolution (HiRes) collimator. Both projection data sets are used to reconstruct a single image using an Inverse Monte Carlo (IMOC) technique with Maximum Likelihood Expectation Maximization (MLEM). Accurate modeling of each collimator is included in the IMOC technique and the reconstructed image is constrained to be consistent with both projection sets. Monte Carlo modeling simulated projection acquisition from two phantoms: a resolution-noise and a cold defect contrast phantom. Projections were simulated for acquisitions of 200K counts with a dual gamma camera HiRes system, yielding 1.9M for an equal time scan using DC (1.8 million counts in the HiSen; 100K in the HiRes). After 300 iterations (10 min), %rms noise decreased for DC (compared to HiResmore » with equal scan time) by a factor of 7 with an increase in reconstructed line-source width from 9 to 10 mm FWHM. For a 2 cm radius defect, contrast decreased 4% (from 0.90 to 0.86) while contrast-to-noise (CNR) increased 210%. For a1 cm defect, contrast decreased 40% while CNR increased 200%. Thus for a select class of imaging tasks, Dual Collimation for SPECT can provide significant improvements in signal-to-noise with only a modest sacrifice of system resolution and contrast.« less

Authors:
; ; ;  [1]
  1. Duke Univ., Durham, NC (United States). Dept. of Radiology
Publication Date:
OSTI Identifier:
5012860
Resource Type:
Journal Article
Journal Name:
IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers); (United States)
Additional Journal Information:
Journal Volume: 38:2; Journal ID: ISSN 0018-9499
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY; PERFORMANCE; SIMULATION; COLLIMATORS; GAMMA CAMERAS; IMAGE PROCESSING; MONTE CARLO METHOD; RESOLUTION; SENSITIVITY; CAMERAS; COMPUTERIZED TOMOGRAPHY; DIAGNOSTIC TECHNIQUES; EMISSION COMPUTED TOMOGRAPHY; PROCESSING; TOMOGRAPHY; 550602* - Medicine- External Radiation in Diagnostics- (1980-)

Citation Formats

Floyd, Jr, C E, Munley, M T, Tourassi, G D, and Bowsher, J E. Dual collimation acquisition for high resolution, low noise SPECT. United States: N. p., 1991. Web. doi:10.1109/23.289391.
Floyd, Jr, C E, Munley, M T, Tourassi, G D, & Bowsher, J E. Dual collimation acquisition for high resolution, low noise SPECT. United States. doi:10.1109/23.289391.
Floyd, Jr, C E, Munley, M T, Tourassi, G D, and Bowsher, J E. Mon . "Dual collimation acquisition for high resolution, low noise SPECT". United States. doi:10.1109/23.289391.
@article{osti_5012860,
title = {Dual collimation acquisition for high resolution, low noise SPECT},
author = {Floyd, Jr, C E and Munley, M T and Tourassi, G D and Bowsher, J E},
abstractNote = {This paper presents Dual Collimation (DC) imaging for SPECT as a technique to improve effective sensitivity with little loss of resolution. For some imaging tasks, DC can overcome the inherent tradeoff between resolution and sensitivity of gamma camera collimators. Simulations were used to investigate the system performance without the expense of collimator fabrication. The author implemented DC for SPECT using simulations of SPECT acquisition using two collimated gamma cameras. Projection data are acquired using two collimators simultaneously: a high sensitivity (HiSen) collimator and a high resolution (HiRes) collimator. Both projection data sets are used to reconstruct a single image using an Inverse Monte Carlo (IMOC) technique with Maximum Likelihood Expectation Maximization (MLEM). Accurate modeling of each collimator is included in the IMOC technique and the reconstructed image is constrained to be consistent with both projection sets. Monte Carlo modeling simulated projection acquisition from two phantoms: a resolution-noise and a cold defect contrast phantom. Projections were simulated for acquisitions of 200K counts with a dual gamma camera HiRes system, yielding 1.9M for an equal time scan using DC (1.8 million counts in the HiSen; 100K in the HiRes). After 300 iterations (10 min), %rms noise decreased for DC (compared to HiRes with equal scan time) by a factor of 7 with an increase in reconstructed line-source width from 9 to 10 mm FWHM. For a 2 cm radius defect, contrast decreased 4% (from 0.90 to 0.86) while contrast-to-noise (CNR) increased 210%. For a1 cm defect, contrast decreased 40% while CNR increased 200%. Thus for a select class of imaging tasks, Dual Collimation for SPECT can provide significant improvements in signal-to-noise with only a modest sacrifice of system resolution and contrast.},
doi = {10.1109/23.289391},
journal = {IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers); (United States)},
issn = {0018-9499},
number = ,
volume = 38:2,
place = {United States},
year = {1991},
month = {4}
}