Henkelman R M, Hardy P A, Bishop J E, Poon C S, Plewes D B
Department of Medical Biophysics, University of Toronto, Ont., Canada.
J Magn Reson Imaging. 1992 Sep-Oct;2(5):533-40. doi: 10.1002/jmri.1880020511.
Fast spin-echo (FSE) sequences are becoming popular for T2-weighted clinical imaging because they result in a severalfold reduction in imaging time and because they provide conventional spin-echo contrast for most tissues. Fat, however, has been observed to have anomalously high signal intensity on FSE images. The present study shows that the brighter fat results from the multiple 180 degrees refocusing pulses, which eliminate diffusion-mediated susceptibility dephasing and suppress J-coupling modulation of the echo train.
快速自旋回波（FSE）序列在T2加权临床成像中越来越受欢迎，因为它们可将成像时间缩短数倍，并且能为大多数组织提供传统自旋回波对比度。然而，人们观察到脂肪在FSE图像上具有异常高的信号强度。本研究表明，脂肪信号增强是由多个180度重聚焦脉冲导致的，这些脉冲消除了扩散介导的磁化率去相位，并抑制了回波链的J耦合调制。
