Characterization of fluid flow using low-spatial-resolution velocity spectra from NMR images

Flow velocity distributions or spectra may be obtained by NMR imaging using an anisotropic three-dimensional Fourier transform pulse sequence in which the low-resolution direction encodes perpendicular velocity. Velocity spectra from regions of interest covering the entire lumens of pipes in a flow phantom containing straight sections, a jet, and a constriction suggest that velocity spectra provide useful information even when the vessels are not spatially well-resolved. The flow in the phantom was characterized and limited measurements were made.