Integration of biaxial planar gradient coils and an RF microcoil for NMR flow imaging

Abstract

A package of two planar gradient coils combined with an RF coil was microfabricated for low-field MRI measurements of velocity flow profiles. The package generates orthogonal gradients in the radial and velocity encoding directions for standard flow imaging experiments. A commercial 0.6 T superconductive magnet was used to test coil performance. For comparison flow imaging was also performed using a commercial set of gradient coils. Velocity profiles were obtained for several volumetric flow rates of water in tubes with inner diameters of 1.02 mm and 1.4 mm. Velocity resolution was 0.13 mm s−1, comparable to that achieved with commercial gradient coils. The quality of the velocity profile was sufficient for viscosity calculations, and thus permits future utilization of this coil package in the design of a portable MRI viscometer.