摘要:目的:探讨平山病的MRI影像特点及其临床应用价值。方法:5例临床确诊平山病病例组和10例正常对照组进行颈椎自然位及屈颈位MRI检查,矢状位T1WI、T2WI及轴位T2WI,观察颈髓、蛛网膜下腔及硬膜外腔变化情况。结果:病例组的5例平山病均系16~20岁男性。自然位:5例下位颈髓均萎缩变扁,硬膜外间隙未显示增宽。屈颈位:5例C5~7颈髓前移变扁中,将变扁颈髓又分为上中下三段,以中段最窄,上下段渐移行至正常;C5~7蛛网膜下腔亦变窄,硬脊膜伴随前移;而C4~7硬脊膜后间隙则增宽,呈新月形影,增宽程度分为轻、中、重三度,最重者位于C6椎体平面,T2加权像及T1WI增强呈高信号,其中1例内见血管流空信号影。对照组为10例志愿者,自然位: 4例C3~7颈髓形态、大小基本一致,6例颈髓自颈3逐渐移行与胸1脊髓其大小一致;屈颈位:颈髓和蛛网膜下腔大小与自然位比较无明显变化,硬膜后间隙自C3平面向下延至T1平面,T2WI上呈均匀线样高信号影。结论:下位颈髓萎缩变扁,屈颈位颈髓及硬脊膜前移、硬脊膜后间隙增宽呈新月形影等,是临床诊断平山病较特征性的MRI表现。Abstract: Objective: To evaluate clinical value and MRI features of Hirayama disease. Methods: Five cases of hirayama disease, which had been clinically confirmed using siemens sonata 1.5T MRI scan, physiological condition and flexional condition, Sagittal view T1WI, T2WI and Axial View T2WI, and GdDTPA enhanced examination, for MRI changes of spinal cord, subarachnoid cavity, duramater of spinal membrae and extra dural space, etc were studied. Results: In case group of 5 cases of hirayama disease, age was mainly in 16–20 years old, All of 5 cases were men. Which were pressed and become thinner of spinal cord, strictic changes of subarachnoid cavity, new moony shape and enlargement changes and pushed forward of extra duramater space, and higher intensity signal of GdDTPA enhancement, and vascular flow effect (one case ) in C5–C7. but also, for contrast group 10 cases of normal volunteer, physiological condition:4 cases in cervical spinal cord with shape and structure were uniformity, and duramater, subarachnoid cavity, extra duramater space etc in C3–C7 were abnormal. Six cases in cervical spinal cord with shape and structure gradully changed from C3 to T1; flexional condition: 10 cases of MRI changes of spinal cord, subarachnoid cavity were as same as it in physiological condition,all of T2 WI, higher intensity signal were homogeneous of extraduramater space in C3–T1. Conclusion: The feature findings of cervical spinal cord became thinner, and cervical cord, durameter pussed forward, new moony shape and enlargment of extradurameter space, vascular flow effusion, etc in MRI were useful value for clinical diagnosis.