MRI VISUALIZATION OF SMALL STRUCTURES USING IMPROVED SURFACE COILS

In this paper we present the spatial resolution enhancement and noise reduction level achieved with an optimized inductively coupled surface coil specifically designed for our experiments, The technique of desi gning and implementing customized coils for magnetic resonance imaging of very small structures is described, We have designed a low cost pr ototype of an inductively coupled circular surface coil, tuned for H-1 magnetic resonance imaging at 200 MHz, The coil is mounted on a custo mized teflon support, The inductive coupling used in this coil improve s the signal-to-noise ratio by reducing various loss mechanisms (speci ally the dielectric losses), Test images have been acquired to determi ne the evolution of induced articular lesions in a rabbit animal model , as well as brain tumors in rats, The images show high spatial resolu tion, excellent B-1 field homogeneity and no ''hot spots'', Comparing these images with those acquired with conventional coils, one finds be tter spatial resolution and signal-to-noise ratio, as well as larger f ield of view with less intense illumination artifact. The methodology can be used in any application that requires high quality imaging of s mall structures. (C) 1998 Elsevier Science Inc.