平山病的MRI诊断

目的：探讨平山病（hirayama disease）的MR影像学表现，提高对该病的认识。方法通过查阅相关文献，回顾性分析2例临床已确诊的平山病MR自然位和过屈位影像表现，观察其低位颈髓的动态变化，并与健康自愿者的同条件扫描影像相比较，总结平山病的MR影像学表现。结果①自然位：曲线多有异常，下段颈髓萎缩，髓内可有异常信号，有失连接现象；②过屈位：所有患者均出现颈髓前移、变扁，硬脊膜后有月牙形、集簇状异常信号影；③2例患者强化检查示过屈位脊膜后异常信号影有强化；④志愿者自然位扫描显示颈椎曲度自然，颈髓粗细均匀，不存在失连接现象，过屈位脊膜后无异常信号影。结论MR颈椎检查特别是过屈位扫描能够显示出平山病的特征性影像学改变，对于平山病的早期诊断具有重大价值。

The magnetic resonance imaging diagnosis of the Hirayama disease

Objective To explore MR imaging findings of Hirayama disease and to improve the recognition of the dis-ease .Methods By reviewing the relevant literature ,the MR imaging features of two patients with Hirayama disease con-firmed clinically were retrospectively analyzed in this work .The dynamic changes of the lower cervical spinal cord in MR images together with normal and flexion position were observed and compare with these of healthy volunteers in the same imaging condition .Finally ,the the MR imaging features of Hirayama disease were summarized .Results Compared with MR images of healthy volunteers ,the MR findings of hirayama disease were;① in normal position ,curvature of the cervi-cal spine was mostly abnormal ,lower cervical spinal exhibited atrophy ,and abnormal intensity and loss of attachment ap-peared within the cervical spinal;② in flexion position ,all patients manifested the forward migration and flattening of cer-vical cord ,crescent or fusiform abnormal intensities on T1 and T2 images in epidural space;and ③ significant enhancement in epidural space with flexion position appeared in these two patients .Conclusion MR imaging of the cervical spine can show the characteristic changes of Hirayama disease ,particularly in flexion position ,which has significant value in early diagnosis of Hirayama disease .