The<unk>  (also called as Resistance<unk> , abbreviated as RI), developed by Léandre Pourcelot , is a measure of pulsatile blood flow that reflects the resistance to blood flow caused by microvascular bed distal to the site of measurement.
Arterial resistivity index
Arterial input function
Coronary flow reserve
Pressure reactivity index
Vascular resistance
PAH clearance
Arteriovenous oxygen difference
Coronary perfusion pressure