Each plot depicts the GCNR metric as a function of the blood channel signal-to-noise ratio, for incrementally decreasing fractional blood volume levels. The fractional moving blood volume ranged from 100% (left), indicating full flow, to 1% (right), indicating nearly no flow. The ppCFPD images produced a higher GCNR for blood flow at all levels of flow, indicating greater discrimination capability in comparison to PD and CFPD.