脊髓型颈椎病患者颈脊髓与椎管匹配关系和脊髓致压因素的动态变化分析

Matching relationship between cervical spinal cord and spinal canal and dynamic change analysis on spinal cord compression factors of patients with cervical spondylotic myelopathy

中文关键词:  脊髓型颈椎病  动态MRI  脊髓  硬膜囊  匹配关系

英文关键词:Cervical spondylotic myelopathy  Dynamic MRI  Spinal cord  Dural sac  Matching relationgship

中文摘要:

  【摘要】 目的：观察脊髓型颈椎病（cervical spondylotic myelopathy，CSM）患者颈脊髓与颈椎管匹配关系的动态变化，分析脊髓椎管匹配关系及脊髓致压因素与脊髓受压风险的关系。方法：收集2018年1月~2021年7月在我院行颈椎动态磁共振成像（dynamic magnetic resonance imaging，DMRI）检查的CSM患者的影像学资料，排除图像不清晰、屈伸角度不理想者，共纳入63例患者，其中男37例，女26例；年龄50~67岁（56.6±4.9岁）。在DMRI横断面T2像上测量颈椎前屈、中立、后伸体位下C3~C7椎间盘水平脊髓面积及硬膜囊面积，计算脊髓与硬膜囊面积的比值（即椎管占有率）；横断面T2像上测量椎间盘突出程度，矢状面T2像上测量黄韧带厚度；横断面T2像上观察脊髓的受压程度，采用改良Muhle分级标准进行脊髓受压分级；观察椎间盘的退变程度，应用Pfirrmann分级标准进行评估。将所有观察节段分为椎间盘突出组及椎间盘非突出组进行比较，分析椎间盘突出是否影响脊髓椎管的匹配关系及黄韧带厚度变化。结果：共测量252个颈椎节段，其中C3/4椎间盘非突出节段33个，突出节段30个；C4/5非突出节段21个，突出节段42个；C5/6非突出节段17个，突出节段46个；C6/7非突出节段27个， 突出节段36个。椎间盘非突出组与突出组都满足脊髓横断面积后伸位>中立位>前屈位，硬膜囊面积前屈位>中立位>后伸位，椎管占有率后伸位>中立位>前屈位，差异均有统计学意义（P＜0.05）。椎间盘突出组中立位与非突出组前屈位、中立位C5/6椎管占有率在C3～C7四个节段中最高，差异均有统计学意义（P＜0.05）。椎间盘突出程度后伸位>中立位>前屈位，脊髓受压分级后伸位>中立位>前屈位，黄韧带的厚度后伸位>中立位>前屈位，差异有统计学意义（P＜0.05）；椎间盘突出组的椎间盘退变等级高于非突出组，差异有统计学意义（P＜0.05）。椎间盘突出组黄韧带较厚，与非突出组比较差异有统计学意义（P＜0.05）。结论：DMRI可显示CSM患者颈脊髓与椎管匹配关系的动态变化，颈椎由前屈位向后伸位运动时椎管占有率增高，脊髓受压风险增大，其中C5/6节段所受影响最明显。

英文摘要:

  【Abstract】 Objectives: To observe the dynamic changes of the matching relationship between cervical spinal cord and cervical canal, and investigate the relationship of the risk of spinal cord compression with matching relationship and spinal cord compression factors. Methods: The imaging data of the patients with cervical spondylotic myelopathy(CSM) who underwent dynamic magnetic resonance imaging(DMRI) in our hospital from January 2018 to July 2021 were collected, and those with unclear images and unsatisfactory flexion and extension angles were excluded. A total of 63 patients, 37 males and 26 females, were included. The age ranged from 50 to 67 years old (56.6±4.9 years old). The horizontal spinal cord area and dural sac area of C3 to C7 intervertebral disc in cross section on DMRI T2 images were measured at anteflexion position, neutral position, and rear protraction position. The ratio of spinal cord to dural sac area(spinal cord occupancy ratio) was calculated. The degree of intervertebral disc herniation on the transverse section of T2 image and the thickness of ligamentum flavum on the sagittal plane of T2 image were measured. The degree of spinal cord compression was observed on T2 images in cross section, and the spinal cord compression was graded with the modified Muhle classification standard. The degree of intervertebral disc degeneration was observed and scored by Pfirrmann grading standard. All C3-C7 segments were divided into group with disc herniation and group without disc herniation for comparison, so as to analyze whether the herniated disc would affect the matching relationship of spinal canal and the change of ligamentum flavum thickness. Results: A total of 252 cervical vertebra segments were measured, including 33 non-herniated C3/4 disc segments and 30 herniated disc segments; 21 C4/5 non-protruding segments and 42 protruding segments; 17 C5/6 non-protruding segments and 46 protruding segments; 27 C6/7 non-protruding segments and 36 protruding segments. In groups without and with disc herniation, for the area of spinal cord, it was: rear protraction position>neutral position>anteflexion position; for the area of dural sac, it was: anteflexion position>neutral position>rear protraction position; the spinal canal occupancy was: rear protraction position>neutral position>anteflexion position. The difference was statistically significant(P<0.05). In groups with disc herniation, the spinal cord occupancy ratio of C5/6 in the neutral position was the highest in the four segments of C3-C7. In groups without disc herniation, the spinal cord occupancy ratio of C5/6 in the anterior flexion position and the neutral position was the highest in the four segments of C3-C7. The degree of disc herniation was: rear protraction position>neutral position>anteflexion position, and the grade of spinal cord compression was: rear protraction position>neutral position>anteflexion position, and the difference was statistically significant(P<0.05). The thickness of ligamentum flavum was: rear protraction position>neutral position>anteflexion position. The grade of disc degeneration in the group with disc herniation was higher than that in the group without disc herniation, and the difference was statistically significant(P<0.05). The thickness of ligamentum flavum in the group with disc herniation was statistically significant compared with that in the group without disc herniation(P<0.05). Conclusions: DMRI can show the dynamic changes of the matching relationship between cervical spinal cord and spinal canal. When the cervical spine moves from flexion to extension, the spinal canal occupancy increases and the risk of spinal cord compression increases, especially at the C5/6 segment.