MR Imaging of Venous and Arterial Flow by a Selective Saturation-Recovery Spin Echo (SSRSE) Method

摘要: Flow velocity imaging studies have been conducted by means of a selective saturation-recovery spin echo technique, and the dependence signal amplitude on interpulse interval, delay, slice-selection gradient, flow was evaluated experimentally. The simple theory predicting steady increase intensity with increasing interval until this latter equals transit time could be verified in phantoms shown to permit measurement blood venous structures such as femoral vein. phantom experiments further showed that final intensity, attained when inversion (TI) = time, decreases velocity, an effect cannot explained influx spins between 90 degree detection pulse 180 refocusing pulse. This reduction is due gradient-induced phase shifts across pixel, caused intralumenal leading destructive interference isochromats. distribution can mapped plotting function for pixels different radial positions. To highlight arterial flow, gating required acquisition delay selected period TI falls zone slow within cardiac cycle. By subtracting images recorded delays, showing enhancement only obtained, illustrated artery thigh.