神经源性肌萎缩的MRI表现

目的：探讨神经源性肌萎缩的病变肌肉的MRI表现及MRI的应用价值。材料和方法：选择30例经临床证实的神经源性肌萎缩患者，选择舌头、肩胛肌带、大腿及双侧手掌行MRI检查。结果：①肌萎缩侧索硬化症者15例，其中舌肌萎缩4例；手掌蚓状肌及骨间肌萎缩6例，受累肌肉见斑片状长T2等T1异常信号影；双侧大腿肌肉见片状混杂信号影1例；4例表现为双侧手掌肌肉萎缩，信号无异常。余受检部位肌肉形态及信号无明显异常。②脊肌萎缩症1例，腓骨肌萎缩症2例，均表现双下肢肌肉萎缩，肌肉内见短T1长T2异常信号。③平山病8例，表现受累肌肉萎缩，手掌蚓状肌及骨间肌见斑片状长T2等T1异常信号影；④4例为单侧下肢的神经源性肌萎缩，表现为肌肉萎缩，肌肉内可见斑片状长T2及短T1混杂信号影。结论：神经源性肌萎缩主要表现为病变区肌肉的萎缩，部分肌肉为脂肪替代，另有部分病变肌肉可表现为肌纤维的坏死性改变。

MRI features of neurogenic muscular atrophy

Objectives:To investigate the MRI features of the neurogenic muscular atrophy(NMA), and evaluate the clinical value of MRI in the diagnosis of these diseases. Materials and Methods: Thirty cases of NMA confirmed clinically underwent MRI. Spin echo sequence, fast spin echo sequence and short tau inversion recovery(STIR) were utilized. Results: Fifteen cases with amyotrophic lateral sclerosis(ALS), in which glossal muscle atrophy seen in 4 cases, lumbrical and interossei atrophy seen in 6 cases and the hyperintense signal intensity was also showed in the involved muscles on T2WI and STIR, the mixed signal intensity of the bilateral thigh was seen in one case, muscular atrophy of bilateral palms was seen in 4 cases and the signal intensity of the involved muscles was normal. The calf atrophy was demonstrated in one case with spinal muscle atrophy and two cases with Charcot-Marie-Tooth syndrome, and the hyperintense signal intensity of the involved muscles was seen on T2WI and T1WI. Lumbrical and interossei atrophy with hyperintense signal intensity on T2WI and STIR was seen in 8 cases with Hirayama Disease. The mixed signal intensity was seen in 4 cases with neurogenic muscular atrophy of unilateral lower extremity. Conclusions: The neurogenic muscular atrophy possesses two characteristics: muscular atrophy and fat replacement and/or muscular necrosis are demonstrated in the diseased muscles.