Fully 3D Bayesian image reconstruction for the ECAT EXACT HR+

Jinvi Qi, Richard M. Leahy, Chinghan Hsu, Thomas H. Farquhar, Simon R Cherry

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

5 Scopus citations


A Fully 3D Bayesian method is described for high resolution reconstruction of images from the Siemens/CTI ECAT EXACT HR+ whole-body PET scanner. To maximize resolution recovery from the system we model depth dependent geometric efficiency, intrinsic detector efficiency, photon pair non-colinearity, crystal penetration and inter-crystal scatter. We also explicitly model the effects of axial rebinning and mashing on the detection probability or system matrix. By fully exploiting sinogram symmetries and using a factored system matrix and automated indexing schemes, we are able to achieve substantial savings in both the storage size and time required to compute forward and backward projections. Bayesian reconstructions are computed using a Huber prior and a shifted-Poisson likelihood model that accounts for the effects of randoms subtraction and scatter. Reconstructions of phantom data show that the 3D Bayesian method can achieve improved FWHM resolution and contrast recovery ratios at matched background noise levels compared to both the 3D reprojection method and an OSEM method based on the shifted-Poisson model.

Original languageEnglish (US)
Title of host publicationIEEE Nuclear Science Symposium & Medical Imaging Conference
EditorsO. Nalcioglu
Place of PublicationPiscataway, NJ, United States
Number of pages5
StatePublished - 1997
Externally publishedYes
EventProceedings of the 1997 IEEE Nuclear Science Symposium - Albuquerque, NM, USA
Duration: Nov 9 1997Nov 15 1997


OtherProceedings of the 1997 IEEE Nuclear Science Symposium
CityAlbuquerque, NM, USA

ASJC Scopus subject areas

  • Engineering(all)


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