Gillams A R, Silver M S, Carter A P
Boston University Medical School, MA 02118, USA.
J Magn Reson Imaging. 1995 Sep-Oct;5(5):545-50. doi: 10.1002/jmri.1880050512.
Two magnetization transfer (MT) contrast effects, a T2-like effect and the improved contrast observed when gadolinium is used with MT, are combined in a single sequence. Forty patients (22 males:18 females; mean age, 45 years (23-87)) with suspected intracranial pathology underwent MRI on a 1.5 Tesla system. Of 46 lesions; seven were ischemic, five infective, seven neoplastic, four hemorrhagic, four multiple sclerosis, seven human immunodeficiency virus (HIV) leukoencephalopathy, nine normal/miscellaneous, and three gliosis. A conventional spin-echo sequence (TR 900 TE 15) was used with on-resonance binomial MT pulses. The sequence was performed postgadolinium +/- MT. The signal intensity ratios +/- MT were: white matter, 0.62 +/- 0.03; gray matter, 0.75 +/- 0.04; ischemia, edema, and demyelination, 0.75 (0.57-0.86); and gadolinium/methemoglobin, 0.85 (0.81-0.98). Areas which exhibited MT had T2-like contrast and those that did not maintained expected contrast for the given parameters. The result was a combination of T2-like contrast, gadolinium enhancement, and dark cerebrospinal fluid (CSF) providing both increased sensitivity to lesions which exhibited both contrast features and improved delineation of periventricular lesions. Furthermore, the differential signal between T2-like contrast of edema and gadolinium enhancement in neoplastic or infective lesions was maintained.
两种磁化传递(MT)对比效应,即类似T2的效应以及使用钆与MT联合时观察到的对比度改善,被整合在一个单一序列中。40例(22例男性:18例女性;平均年龄45岁(23 - 87岁))怀疑有颅内病变的患者在1.5特斯拉系统上接受了MRI检查。在46个病变中,7个为缺血性病变,5个为感染性病变,7个为肿瘤性病变,4个为出血性病变,4个为多发性硬化,7个为人免疫缺陷病毒(HIV)白质脑病,9个正常/其他病变,3个为胶质增生。使用常规自旋回波序列(TR 900 TE 15)并施加共振二项式MT脉冲。该序列在注射钆剂后进行,可选择是否加用MT。加用/未加用MT时的信号强度比分别为:白质,0.62±0.03;灰质,0.75±0.04;缺血、水肿和脱髓鞘病变,0.75(0.57 - 0.86);钆剂/高铁血红蛋白,0.85(0.81 - 0.98)。表现出MT的区域具有类似T2的对比度,而未表现出MT的区域则保持给定参数下的预期对比度。结果是类似T2的对比度、钆剂增强和暗脑脊液(CSF)相结合,既提高了对具有两种对比特征病变的敏感性,又改善了脑室周围病变的轮廓。此外,肿瘤性或感染性病变中水肿的类似T2对比度与钆剂增强之间的差异信号得以保留。