不同屈曲位颈椎MRI检查对平山病特异性征象的影响

Different cervical flexion positions of MRI in Hirayama disease

目的比较颈椎屈曲不同角度平山病患者的MRI表现,探讨颈椎屈曲角度的调节对平山病的MRI诊断价值。材料与方法 19例临床确诊为平山病的患者,使用自行研发的辅助诊断设备行不同屈曲位颈椎MRI检查,屈曲角度包括:0°(中立位)、25°、30°、35°、40°,观察不同屈曲位MRI三个典型征象显示情况:脊髓萎缩、背侧硬脊膜前移、硬膜外间隙增宽。测量不同屈曲角度硬膜外间隙最大矢状径(d)及同层面椎管矢状径(D),并计算d/D。结果平山病患者MRI特异性征象在屈曲角度25°及以上与屈曲0°存在差异(P=0.00),d/D平均值随屈曲角度增加在一定范围内增加,35°时最大。结论屈曲位MRI检查可以影响颈椎背侧硬脊膜前移、脊髓萎缩、硬膜外间隙增宽等征象。

Objective： To investigate different cervical flexion positions in Hirayama disease （HD） for the effects on these MRI features by cervical flexion angle. Materials and Methods： The cervical MR scans were carried out by a self-made equipment with a superconducting 1.5 T system. MRI examinations in different flexion positions （0° 25°, 30°, 35°, 40°） of 19 patients, who were clinical diagnosed as HD. To summarize three MRI features including asymmetric cord flattening, anterior shifting of the posterior wall of the cervical dural canal （ASD）, widening of cervical epidural space. The maximum sagittal diameters （d） of widened cervical epidural space and the cervical canal sagittal diameters （D） at the same level were measured. The d/D values at different angles were calculated and compared. Results： The appearance of MR1 features were different between 0° group and other 4 larger angles groups （P=-0.00）. The mean d/D value was changing following different angles, reached max value in 35°. Conclusions： Neck flexion angles have effects on ASD, widening of cervical epidural space.