  Single Photon Emission Computed Tomography (SPECT) is one of the nuclear
medicine imaging modalities used for functional analysis of animal and human
organs. Gamma rays emitted from the scanned body are filtered with collimators
and detected by the SPECT head that is composed of an array of gamma detectors.
The conventional reconstruction algorithms do not deem the uncertainty level
that is associated with the field of view of SPECT collimators. In this paper,
we incorporate the probabilistic programming approach for SPECT image
reconstruction. No-U-Turn Sampler (NUTS) is used to estimate the scanned object
system by considering uncertainty. The obtained results indicate that the
presented work in 3D SPECT image reconstruction surpassed over the conventional
reconstruction methods in terms of generating uncertainty information. However,
the reconstruction time needs to be improved further for phantom sizes of
128x128x128 voxels and higher.
