The QPET algorithm for absolute blood flow quantification utilizes a previously-validated model for left ventricular segmentation and contouring developed by our center and applies it to dynamic data to quantify regional myocardial perfusion and absolute regional myocardial blood flow (MBF).

To obtain MBF, this algorithm uses LV myocardial regions of interest and automatically-assigned left and right ventricular blood pool regions which are used for the determination of the input bolus and for spillover correction in the myocardial region. Time-activity curves are generated from the acquired data, beginning with initiation of ⁸²Rb infusion. MBF (in mL/min/g) is then calculated by fitting previously validated ⁸²Rb, 2-compartment kinetic models (see references below) and correcting for the nonlinear dependence of the extraction fraction on flow for ⁸²Rb.

Finally, the map of Coronary Flow Reserve (CFR) is derived by dividing the stress and rest flow polar maps. Regional distributions of MBF and CFR of the myocardium can be represented on a per-vessel basis or in a 17-segment AHA model.