NMR MICROSCOPY USING LARGE, PULSED MAGNETIC-FIELD GRADIENTS

The use of imaging schemes which employ large pulsed magnetic-field gr adients to avoid susceptibility and diffusion artifacts in NMR microsc opy is considered. The theory relating to these artifacts is briefly r eviewed in the context of two specific pulse sequences, namely two-dim ensional (i.e., slice-selective) phase-phase encoding and two-dimensio nal phase-frequency encoding in which the magnetization is recycled in a CPMG multi-pulse train. Experiments have been carried out using a s pecially constructed coil set which achieves gradient strengths of up to 6 T m(-1) and a number of images are shown, both from a susceptibil ity phantom and from a geranium petiole. Some of the inherent advantag es and disadvantages of the respective imaging schemes are demonstrate d. (C) 1995 Academic Press, Inc.