Zerhouni E A, Parish D M, Rogers W J, Yang A, Shapiro E P
Russell H. Morgan Department of Radiology and Radiolgical Science, Johns Hopkins Medical Institutions, Baltimore, MD 21205.
Radiology. 1988 Oct;169(1):59-63. doi: 10.1148/radiology.169.1.3420283.
Specified regions of the myocardium can be labeled in magnetic resonance (MR) imaging to serve as markers during contraction. The technique is based on locally perturbing the magnetization of the myocardium with selective radio-frequency (RF) saturation of multiple, thin tag planes during diastole followed by conventional, orthogonal-plane imaging during systole. The technique was implemented on a 0.38-T imager and tested on phantoms and volunteers. In humans, tags could be seen 60-450 msec after RF saturation, thus permitting sampling of the entire contractile phase of the cardiac cycle. Tagged regions appear as hypointense stripes, and their patterns of displacement reflect intervening cardiac motion. In addition to simple translation and rotation, complex motions such as cardiac twist can be demonstrated. The effects of RF pulse angle, relaxation times, and heart rate on depiction of the tagged region are discussed.
心肌的特定区域可在磁共振（MR）成像中进行标记，以便在收缩过程中作为标记物。该技术基于在舒张期通过对多个薄标记平面进行选择性射频（RF）饱和来局部扰动心肌的磁化，随后在收缩期进行传统的正交平面成像。该技术在0.38-T成像仪上实现，并在体模和志愿者身上进行了测试。在人体中，RF饱和后60 - 450毫秒可以看到标记，从而允许对心动周期的整个收缩期进行采样。标记区域呈现为低信号条纹，其位移模式反映了其间的心脏运动。除了简单的平移和旋转外，还可以展示诸如心脏扭转等复杂运动。讨论了RF脉冲角度、弛豫时间和心率对标记区域描绘的影响。
