  The Lightfield Single Photon Emission Computed Tomography (L-SPECT) system is
developed to overcome some of the drawbacks in conventional SPECT by applying
the idea of plenoptic imaging. This system displayed improved performance in
terms of reduced information loss and scanning time when compared to the SPECT
system which has a conventional collimator. The SPECT system is transformed
into L-SPECT system by replacing the conventional collimators with micro-range
multi-pinhole arrays. The field of view (FOV) of the L-SPECT system is enhanced
by reshaping the detector head into ring-type by tiling small detector modules.
The L-SPECT system with modular partial ring detectors (MPRD L-SPECT) exhibits
cylindrical artefacts during volumetric reconstruction. Hence, here the work is
focused to remove the cylindrical artefacts in the reconstruction of the
examined objects by changing the scanning orbit. The enhancement is done such
that the center of scanning of the L-SPECT system with MPRD L-SPECT is shifted
at different values. The reconstruction quality of MPRD L-SPECT with and
without center shifting is evaluated in terms of the Full Width at Half Maximum
(FWHM) and Modulation Transfer Function (MTF). Moreover, the visual comparison
is also examined. The results indicate that center shifting of MPRD L-SPECT
overcomes the problem of the central artefact with improved FWHM. By increasing
MPRD's scanning center shift gap, the spatial resolution can be further
improved.
