NMR Flow Imaging

Abstract

The present study describes a method for measuring a spatial distribution of flow velocity in fluid. This method employs two selective irradiation pulses; the first pulse is used for selective saturation and the second pulse is used for selective observation. To image flowing fluid correctly, images are reconstructed from a set of second echoes in a pulse sequence similar to Carr-Purcell-Meiboom-Gill sequence. The velocity image is computed using two images; one is that of the nuclear spin density and the other is that with 100 msec delay time between the two selective irradiation pulses. The obtained velocity distribution of water in a circular pipe is parabolic and agrees well with that of Poiseuille flow, which has proved the method developed here of great use in the study of fluid flow.