A Comparative Assessment of Dynamic and Conventional Thallium-201 SPECT Myocardial Perfusion Imaging: Monte Carlo Simulations and Case Studies

Clinical myocardial perfusion SPECT is commonly performed using static imaging. Dynamic SPECT enables extraction of quantitative as well as relative perfusion information. We aimed to evaluate the ability of dynamic SPECT for regular perfusion assessment in comparison to conventional SPECT in the context of thallium-201. Simulations were performed utilizing a 4D-NCAT phantom for a dual-head gamma camera via the SIMIND Monte-Carlo simulator. 64s acquisition time-frames were used to track these dynamic changes. Different summations of time-frames were performed to create each dataset, which were compared to a standard static dataset. In addition, the effect of different delay-times post-injection was assessed. Twenty-segment analysis of perfusion was performed via the QPS analyser. Dynamic data were subsequently acquired in clinical studies using simulation-optimized protocols. For different summations of time-frames, perfusion scores in the basal and mid regions revealed 14.4% and 7.3% increases in dynamic SPECT compared to conventional imaging, with maximum changes in the basal anterior, while the distal and apical segments did not show noticeable changes. Specifically, dynamic imaging including 4 to 6 time-frames yielded enhanced correlation (R=0.957) with conventional imaging, in comparison to the usage of less time frames. Greatest correlation with conventional imaging was obtained for post-injection delays of 320 to 448s (R=0.982 to R=0.988). While dynamic SPECT opens up an important opportunity for quantitative assessment (e.g. via generation of kinetic parameters), it was shown to generate highly consistent perfusion information compared to established conventional imaging. Future work focuses on merging these two important capabilities.