平山病的MRI诊断——附2例报告及文献复习

目的研究平山病的临床及磁共振成像特征。方法2例经临床确诊的平山病患者，临床特征为隐匿起病的单侧上肢远端肌无力、肌萎缩，其中1例近期伴胸大肌萎缩。2例患者均行颈椎自然体位及屈颈位MRI检查，颈椎X线平片，血生化检查，脑脊液及肌电图检查。复习相关文献。结果自然体位MRI见低位颈髓萎缩变扁，屈颈位MRI显示见颈髓前移、变扁，脊膜后可见月牙形略长T1长T2异常信号及其内的流空信号，增强扫描强化明显。肌电图提示神经源性损害。结论平山病的自然位、屈颈位MRI所见的动态改变具有特征性，对诊断及了解平山病的发病机制有重要价值。

Magnetic resonance imaging diagnosis in hyrayama disease:a report of two cases and articles review

Objective To research the clinical and magnetic resonance imaging features in Hyrayama disease. Methods 2 patients were consistent with the diagnostic criteria of Hirayama disease who had insidious muscular atrophy and weakness of the hand and forearm, one of which was accompanied pectoralis major amyotrophy. Spinal MRI of the cervical region in neutral neck position and a Iully flexed neck position were performed. Cervical plain film, routine blood test, cerebrospinal fluid examination and electromyography （EMG） were also performed. And Articles were reviewed. Results In netrual position MRI images showed atrophy of the lower cervical cord. In fully neck flexed MRI images showed forward displacement and flattening of the lower cervical cord, and a crescent-shaped slightly hypointense TI and hyperintense T2 signal area with signal void behind the cord. The crescent shaped area enhanced significantly in enhanced MRI. EMG revealed neurogenie damage. Conclusion The dynamic changes of the cervical cord during neck flexion in Hirayama disease by MRI examination are characteristic, which can help doctors to make diagnosis and contribute to the pathogenesis.