Performance evaluation of block-iterative algorithms for SPECT reconstruction

Chi Liu, Lana Volokh, Xide Zhao, Jingyan Xu, Taek Soo Lee, Benjamin M.W. Tsui

Research output: Chapter in Book/Report/Conference proceedingConference contribution


The purpose of this study is to evaluate the performance of four block-iterative algorithms, ordered-subsets expectation-maximization (OS-EM), reseated block-iterative EM (RBI-EM), modified row-action maximum likelihood algorithm (RAMLA) and reseated block-iterative maximum a posteriori EM (RBI-MAP-EM), for In-111 ProstaScint® SPECT image reconstruction. The 3D NCAT phantom with realistic In-111 ProstaScint® activity distribution was used in the study. Noise-free and noisy projections of the phantom obtained using a medium-energy general-purpose (MEGP) collimator were generated using Monte Carlo simulation methods. For each algorithm, the projection data were reconstructed with the compensations for attenuation, collimator-detector response and scatter. Image quality was evaluated in terms of FWHM of a profile through a small blood vessel, normalized mean square error (NMSE), ensemble normalized standard deviation (NSDE) of a uniform region of interest (ROI) in the reconstructed image measured from 30 noise realizations, and regional NSD (NSDR) of an ROI measure from 1 noise realization. The results indicated that, RBI-EM has superior performance than that of OS-EM when less than 4 views per subset were used and similar performance when 4 or more views per subset were used. Modified RAMLA provides similar image quality with a slower convergence rate than that of OS-EM. Using well-chosen parameters, RBI-MAP-EM provides increased noise smoothing with less loss in resolution and error. We conclude that when compared with OS-EM, the RBI-EM and modified RAMLA have the same performance at a slower convergence rate, while the RBI-MAP-EM has superior performance and can potentially improve image quality.

Original languageEnglish (US)
Title of host publication2005 IEEE Nuclear Science Symposium Conference Record -Nuclear Science Symposium and Medical Imaging Conference
Number of pages5
StatePublished - 2005
EventNuclear Science Symposium Conference Record, 2005 IEEE - , Puerto Rico
Duration: Oct 23 2005Oct 29 2005

Publication series

NameIEEE Nuclear Science Symposium Conference Record
ISSN (Print)1095-7863


OtherNuclear Science Symposium Conference Record, 2005 IEEE
Country/TerritoryPuerto Rico

ASJC Scopus subject areas

  • Radiation
  • Nuclear and High Energy Physics
  • Radiology Nuclear Medicine and imaging


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