Method of localized NMR spectroscopy for the measurment of overlapping signal from coupled spin systems

摘要

A method for localized NMR spectroscopy having a sequence of radio frequency (RF) pulses for excitation and refocussing of spins in metabolites under investigation in an investigation volume, wherein the excitation is effected through an RF pulse of narrow bandwidth in the presence of a slice selection gradient, as well as, if required, an additional limitation of the investigation volume through utilization of refocussing pulses of narrow bandwidth in the presence of mutually orthogonal slice selection gradients, is characterized in that a read- out time te desired for signal production comprises an n-fold repetition of a partial sequence of RF pulses and, if required, gradient switchings at a time separation tcp2 with respect to each other, wherein a refocussing of the spins is effected within each of these refocussing time intervals using a refocussing pulse. In this fashion, loss of useful signal due to background is largely avoided so that the full intensity of multiplet signals can be observed with echo times of 20-30 ms in proton spectra with the wide signals of rapidly decaying substances having died off.