MRI运动扫描分析脊髓型颈椎病的脊髓致压因素

目的 探讨动态运动MR扫描揭示椎管内退变结构对脊髓的动力性致压作用，提高脊髓型颈椎病的早期诊断作用。方法 在开放式MR机上，通过颈椎的多角度分次扫描、关节运动扫描和MR透视扫描3种方法检查60例颈椎病患者，分别观察退变结构在常规自然位、前屈位和后伸位时对脊髓的致压作用。结果 (1)椎管内退变结构在颈椎伸屈活动时常形成较自然位更加严重的脊髓压迫征象，而且它们间还有“动态叠加作用”。(2)椎间盘突出(29例)、椎体骨赘增生、椎体错位滑脱(7例)、后纵韧带增厚(36例)等在前屈位时常较自然位形成更明显的混合性致压物。(3)34例患者的退变黄韧带在后伸位时皱折凸入椎管，凸入黄韧带又可与脊髓前方致压物形成“钳夹效应”而严重压迫脊髓(9例)。(4)14例患者在伸屈活动时加重椎体的错位滑脱。(5)硬膜囊前间隙在前屈位(41例)和后伸位(16例)时较自然位变小；囊后间隙后伸位变小见于43例，前屈位对其影响较小(4例)。结论 颈椎病患者动态MR扫描不仅从形态上而且能从致病作用上显示出早期的、潜在性的、动态性的脊髓致压因素，从而起到较静态扫描更早期地对脊髓型颈椎病的诊断作用。

Imaging analysis of cord compression factors in CSM by using MRI motion scan tecHnique

Objective To study the dynamic etiological effects of degeneration structure in cervical spine with motion MRI image, and to obtain the early diagnosis of CSM. Methods By flexing the patient forward and backward with the joint motion device, a total of 60 cases received MRI study in open MR feature. The motion MRI technique included the multi-angle scan, the joint motion scan, and the MR Fluoroscopy. Results (1) The spinal cord compression due to degeneration structure in flexion-extension was more significant than that in static position, it even had pile up effect. (2) The disc herniation (in 29 cases), the vertebral osteophyte, the segmental instability (in 7 cases), and the thickening of posterior longitudinal ligament (in 36 cases) could cause more serious mixture compression to the cord in anteflexion than in natural position. (3) In extension, the degenerative yellow ligaments (in 34 cases) often folded and encroached upon the spinal canal, which usually formed pincers effect with anterior compression (in 9 cases). (4) The flexion-extension movement could cause lower cervical instability founded in 14 cases. (5) The anterior space of dural sac could be decreased in flexion (in 41 cases) as well as in extension(in 16 cases), and in 43 cases, the posterior space could also be narrowed in extension, but not evident in flexion(in only 4 cases). Conclusion By using the motion MRI scan, the early, potential and dynamic compression factors of cervical spinal cord could be demonstrated not only in shape but also in pathogenesis. So the motion scan can make the diagnosis of CMS earlier than static scan does.