What are the necessary corrections for dynamic cardiac SPECT?
Myocardial blood flow (MBF) and myocardial flow reserve (MFR) are important physiologic parameters for the detection of hemodynamically significant coronary artery disease (CAD) and have been shown to improve diagnostic accuracy and risk stratification of myocardial perfusion imaging (MPI), beyond that provided by relative perfusion abnormalities alone. Quantitative assessment of MBF can be obtained from cardiac PET, however, it is infrequently used in clinical practice due to the limited availability of PET scanners, suitable radiotracers, and dedicated software as compared to the widely used SPECT. MPI SPECT with conventional Anger technology has been traditionally limited to visual analysis or semiquantitative perfusion analysis. SPECT quantification of MBF requires fast acquisition of dynamic data in 5-10 seconds, as well as corrections, mainly for attenuation and scatter, which enable absolute measurement.