(A) study on RF coils for high-field NMR imaging system

Abstract

Since the advent of superconducting magnets for NMR imaging, there has been a trend towards higher magnetic field strength for higher sensitivity or better signal-to-noise ratio. As NMR imaging moves towards higher field strength, RF coils associated with the NMR system require new design principles and fabracation techniques. This study deals with frequency limits of conventional low frequency RF coils and operation principles of various types of high frequency coils as well. Performance comparison of the slotted cylinder resonator (STR) coil with ringresonator is presented. We have improved the SCR to achieve a large size whole body coil suitable for 2.0 Tesla (85.14 MHz) NMR imaging system. An accurate design method on parallel type distributed phase multiwire coil by using coupled transmission line theory is suggested.