Measurement of blood flow and perfusion in the cardiovascular system.

Complete evaluation of cardiovascular disease by a single imaging technique requires measurement of bulk flow in blood vessels and estimation of relative or ideally absolute perfusion at the tissue level. Magnetic resonance (MR) measurement of blood flow in arteries and veins has been done using the velocity-encoded phase cine gradient echo technique. This technique has been applied with cine MR to measure normal and pathologically high velocities. Measurement of relative perfusion in the myocardium has used the intravenous injection of T1 relaxation enhancing and magnetic susceptibility MR contrast media with rapid image acquisition using echoplanar imaging. MR images (MRIs) acquired during steady-state distribution or during the first passage of these contrast media have depicted ischemic myocardial regions.