A study of the influence of local variations in myocardial thickness on SPECT perfusion imaging

The objective of this project was to study the impact of local variations in myocardial thickness on single photon emission computed tomography (SPECT) perfusion imaging using segmented high-resolution gated-computer tomography (CT) data of the heart to define source distributions. High-resolution breath-hold gated CT data of 16 patients were obtained using a GE Lightspeed multislice CT system. Transverse slices (512/spl times/512) with x-y pixel size of 0.039 cm and a slice thickness of either 0.25 cm or 0.125 cm were segmented to obtain left-ventricular (LV) and right-ventricular (RV) myocardial walls for all time frames of the cardiac cycle. Polar maps of myocardial thickness were generated using radial and short-axis slices of the LV Absolute quantitation was performed on the myocardium thickness polar maps. The segmented LV and RV were also incorporated in the gated MCAT phantom, and analytical SPECT projections generated using typical acquisition parameters.