An NMR method for volume-selective determination of velocities by frequency encoding

Abstract

An NMR frequency encoding method is described permitting the non-invasive and volume-selective measurement of velocities in a range of typically 0.5 mm s^-1. All three components of the velocity vector can be determined in one shot by the aid of an extended version of the pulse sequence. Test experiments with a rotating phantom sample led to results in perfect agreement with expectations. The method is discussed in comparison with further proposals based on 'fresh spin inflow', 'phase encoding' and the use of the 'modified stimulated echo'.