Advanced search
1 file | 1.36 MB

Accurate Monte Carlo modelling of the back compartments of SPECT cameras

Erwann Rault (UGent) , Steven Staelens (UGent) , Roel Van Holen (UGent) , Jan De Beenhouwer (UGent) and Stefaan Vandenberghe (UGent)
Author
Organization
Project
Ghent researchers on unfolded proteins in inflammatory disease (GROUP-ID)
Abstract
Today, new single photon emission computed tomography (SPECT) reconstruction techniques rely on accurate Monte Carlo (MC) simulations to optimize reconstructed images. However, existing MC scintillation camera models which usually include an accurate description of the collimator and crystal, lack correct implementation of the gamma camera's back compartments. In the case of dual isotope simultaneous acquisition (DISA), where backscattered photons from the highest energy isotope are detected in the imaging energy window of the second isotope, this approximation may induce simulation errors. Here, we investigate the influence of backscatter compartment modelling on the simulation accuracy of high-energy isotopes. Three models of a scintillation camera were simulated: a simple model (SM), composed only of a collimator and a NaI(Tl) crystal; an intermediate model (IM), adding a simplified description of the backscatter compartments to the previous model and a complete model (CM), accurately simulating the materials and geometries of the camera. The camera models were evaluated with point sources (Ga-67, Tc-99m, In-111, I-123, I-131 and F-18) in air without a collimator, in air with a collimator and in water with a collimator. In the latter case, sensitivities and point-spread functions (PSFs) simulated in the photopeak window with the IM and CM are close to the measured values (error below 10.5%). In the backscatter energy window, however, the IM and CM overestimate the FWHM of the detected PSF by 52% and 23%, respectively, while the SM underestimates it by 34%. The backscatter peak fluence is also overestimated by 20% and 10% with the IM and CM, respectively, whereas it is underestimated by 60% with the SM. The results show that an accurate description of the backscatter compartments is required for SPECT simulations of high-energy isotopes (above 300 keV) when the backscatter energy window is of interest.
Keywords
ENERGY, LEFT-VENTRICULAR DYSFUNCTION, GATE, PET, CONTAMINATION, RECONSTRUCTION, DISA SPECT, SIMULATION, SCATTER COMPENSATION, DETECTOR RESPONSE FUNCTIONS

Downloads

  • (...).pdf
    • full text
    • |
    • UGent only
    • |
    • PDF
    • |
    • 1.36 MB

Citation

Please use this url to cite or link to this publication:

Chicago
Rault, Erwann, Steven Staelens, Roel Van Holen, Jan De Beenhouwer, and Stefaan Vandenberghe. 2011. “Accurate Monte Carlo Modelling of the Back Compartments of SPECT Cameras.” Physics in Medicine and Biology 56 (1): 87–104.
APA
Rault, E., Staelens, S., Van Holen, R., De Beenhouwer, J., & Vandenberghe, S. (2011). Accurate Monte Carlo modelling of the back compartments of SPECT cameras. PHYSICS IN MEDICINE AND BIOLOGY, 56(1), 87–104.
Vancouver
1.
Rault E, Staelens S, Van Holen R, De Beenhouwer J, Vandenberghe S. Accurate Monte Carlo modelling of the back compartments of SPECT cameras. PHYSICS IN MEDICINE AND BIOLOGY. 2011;56(1):87–104.
MLA
Rault, Erwann, Steven Staelens, Roel Van Holen, et al. “Accurate Monte Carlo Modelling of the Back Compartments of SPECT Cameras.” PHYSICS IN MEDICINE AND BIOLOGY 56.1 (2011): 87–104. Print.
@article{1265585,
  abstract     = {Today, new single photon emission computed tomography (SPECT) reconstruction techniques rely on accurate Monte Carlo (MC) simulations to optimize reconstructed images. However, existing MC scintillation camera models which usually include an accurate description of the collimator and crystal, lack correct implementation of the gamma camera's back compartments. In the case of dual isotope simultaneous acquisition (DISA), where backscattered photons from the highest energy isotope are detected in the imaging energy window of the second isotope, this approximation may induce simulation errors. Here, we investigate the influence of backscatter compartment modelling on the simulation accuracy of high-energy isotopes. Three models of a scintillation camera were simulated: a simple model (SM), composed only of a collimator and a NaI(Tl) crystal; an intermediate model (IM), adding a simplified description of the backscatter compartments to the previous model and a complete model (CM), accurately simulating the materials and geometries of the camera. The camera models were evaluated with point sources (Ga-67, Tc-99m, In-111, I-123, I-131 and F-18) in air without a collimator, in air with a collimator and in water with a collimator. In the latter case, sensitivities and point-spread functions (PSFs) simulated in the photopeak window with the IM and CM are close to the measured values (error below 10.5%). In the backscatter energy window, however, the IM and CM overestimate the FWHM of the detected PSF by 52% and 23%, respectively, while the SM underestimates it by 34%. The backscatter peak fluence is also overestimated by 20% and 10% with the IM and CM, respectively, whereas it is underestimated by 60% with the SM. The results show that an accurate description of the backscatter compartments is required for SPECT simulations of high-energy isotopes (above 300 keV) when the backscatter energy window is of interest.},
  author       = {Rault, Erwann and Staelens, Steven and Van Holen, Roel and De Beenhouwer, Jan and Vandenberghe, Stefaan},
  issn         = {0031-9155},
  journal      = {PHYSICS IN MEDICINE AND BIOLOGY},
  keywords     = {ENERGY,LEFT-VENTRICULAR DYSFUNCTION,GATE,PET,CONTAMINATION,RECONSTRUCTION,DISA SPECT,SIMULATION,SCATTER COMPENSATION,DETECTOR RESPONSE FUNCTIONS},
  language     = {eng},
  number       = {1},
  pages        = {87--104},
  title        = {Accurate Monte Carlo modelling of the back compartments of SPECT cameras},
  url          = {http://dx.doi.org/10.1088/0031-9155/56/1/006},
  volume       = {56},
  year         = {2011},
}

Altmetric
View in Altmetric
Web of Science
Times cited: