NMR velocity-selective excitation composites for flow and motion imaging and suppression of static tissue signal.

We propose a technique aimed at increasing the sensitivity of magnetic resonance imaging (MRI) measurements to the signal from moving material. The technique is formulated within the framework of a velocity phase-encoding strategy. The salient new feature of the protocol is the application of an excitation pulse, following the conventional 90 degrees excitation and bipolar phase gradient modulation pulses, which rotates the magnetization through -90 degrees . The whole comprises a velocity-selective excitation composite which leaves only magnetization of moving material in the transverse plane.