A dynamic cardiac SPECT computer simulation

A computer simulation was developed to investigate the effects that cardiac motion, time-varying tracer activity, and differences in relative attenuation between the blood and extravascular (tissue) activity regions have on kinetic modeling using dynamic SPECT (single photon emission computed tomography) imaging. The projection/reconstruction process did not introduce significant errors in the fitted parameters. The blood and tissue activity curves showed little difference for various heart rates >5 BPM for 10 s scans. If the blood region of interest was contaminated by tissue, then both the forward (k₂₁) and back (k₁₂) exchange increased depending on the amount of contamination. Spillover of tissue activity into the blood region due to cardiac motion increased f_v but had little effect on k₂₁ and k₁₂. Nonuniform attenuation changed k₂₁ and f_v significantly (>32% change). Only the parameters f_v and k₂₁ were dependent on the relative attenuation difference between the blood and tissue activity regions