Development of Rapid SPECT Acquisition Protocol for Myocardial Perfusion Imaging

Advances in reconstruction techniques and instrumentation improve image quality. Improved image quality could either improve confidence and diagnostic ability, or increase throughput, and lower injected dose. Current imaging guidelines give insufficient consideration to advances in iterative reconstruction methods that include collimator modeling, attenuation, and scatter correction, and best matched acquisitions. Thus advanced reconstruction is often sub-optimally used in a clinical setting. In this work, we first characterize the effects of various acquisition and reconstruction protocols with the explicit aim to reduce scan time without adverse affects as compared to FBP driven protocols. For this we characterize image features, such as nonuniformity and wall thickness of the cardiac insert inside the large anthropomorphic torso phantom (Data Spectrum) and correlate them with human observer ROC results. When reconstructing the data with OSEM with 3D collimator and detector response compensation ("Flash3D") we found that the detection ability is not impacted when using 6deg angular steps, and thus reducing the acquisition time by 50%, as compared to the current method. A further reduction can be achieved if the rest study is scanned in the continuous instead of the step-and-shoot mode (10%). Dwell time can also be reduced slightly; however the myocardial count density should not be below at least 1 cnt/mm² for rest and summed stress. Clinical trials need to confirm the findings.