进行性肌营养不良的MRI表现和鉴别诊断

MRI features and differential diagnosis of progressive muscular dystrophy

目的：分析进行性肌营养不良（PMD）的MRI表现，为临床诊断提供参考。方法：搜集经病理证实的11例PMD患者的MRI资料，分析其信号特点及不同部位肌肉的脂肪替代程度。结果：11例PMD在FSE T1WI上均呈等、高混杂信号，在压脂FSET2wI上呈高信号4例，呈等信号7例，11例PMD皮肤信号均无异常改变。11例PMD患者中，大收肌、股二头肌和缝匠肌脂肪替代3～4级者分别为8倒、8例、1例；大收肌、股二头肌和缝匠肌脂肪替代0～1级者分别为1例、1例、7例。结论：脂肪替代是PMD的特征性表现，缝匠肌脂肪替代时的回避现象对诊断PMD有提示性作用。

Objective：To analysis the MRI features of progressive muscular dystrophy and to provide the reference for the clinical diagnosis. Methods. 11 cases diagnosed as progressive muscular dystrophy （PMD） by pathology from March 2011 to June 2013 were analyzed by the signal characteristics and degree of fat replacement. Results： 11 cases of PMDs showed intermediate to high signal on Ti-weighted images （T1WI）. Tz-weighted fat-suppressed sequence showed byperin- tensity in 4 cases and isointensity in 7 cases. The skin signal of 11 cases of PMDs were unremarkable. In adductor magnus muscle, biceps femoris muscle and sartorius, the degrees of fat replacement between Grade 3 -4 and Grade 0h 1 were 8,8, 1 and 1,1,7 cases respectively. Concusion：Fat replacement is the feature of PMD. The fat sparing phenomenon of sartorius muscle has a prediction for PMD.