颈椎中立位核磁共振检查对突出颈椎间盘体积及颈椎曲度的影响

Effect of neutral position magnetic resonance imaging on cervical discs herniation volume and cervical curvature

背景:颈椎中立位MRI被广泛应用于脊髓型颈椎病的诊断和治疗,但患者在重复进行颈椎MRI检查时,头颈部不可能保持完全相同的姿势,患者颈椎被床面限制于某一个特定位置,颈椎可能有矢状面内的微小伸屈运动,头部也可能发生一定的仰屈度变化。颈椎中立位状态下颈椎和头部的这种变化是否会影响突出颈椎间盘的体积和颈椎曲度目前尚不清楚。目的:采用人工智能辅助测量,分析脊髓型颈椎病患者短期内2次颈椎中立位状态下MRI检查突出颈椎间盘体积、颈椎曲度测量的精准性与可靠性。方法:回顾性分析2012年6月至2023年6月接受保守治疗并在3个月内2次行颈椎MRI检查的脊髓型颈椎病患者。作者首次提出使用枕胸间距和枕胸角来评估颈椎中立位时头部仰屈度的变化,并参照首诊枕胸角的角度,将复诊患者分为枕胸角增大组和减小组。通过人工智能测量软件辅助或人工测量突出颈椎间盘的体积、C2-6 Cobb角及颈椎(C3-C7)曲率。正态分布数据用x-±s表示,非正态分布数据用中位数(四分位数间距)表示。采用Spearman秩相关系数分析Cobb角、颈椎(C3-C7)曲率变化与突出颈椎间盘体积变化的相关性。结果与结论:①共有104例脊髓型颈椎病患者,326个突出颈椎间盘,枕胸角增大组及枕胸角减小组分别有47例和57例患者;②头部仰屈指标:首诊和复诊时,枕胸间距、枕胸角均无显著差异;枕胸间距的变化量为0.035(3.23)mm,枕胸角变化量为-0.31(3.28)°,枕胸间距与枕胸角的变化量偏移范围较小,且无显著相关性;③颈椎曲度指标:首诊和复诊时,C2-6 Cobb角、C3-C7曲率无显著差异;枕胸角增大组和减小组C2-6 Cobb角、C3-C7曲率均无显著差异;④首诊和复诊时,突出颈椎间盘体积无显著差异;枕胸角增大组及减小组突出颈椎间盘体积均无显著差异;突出颈椎间盘体积的变化量与C2-6 Cobb角、C3-C7曲率的变化量无显著相关性;⑤结果说明,颈椎中立位状态下,颈椎被(床板)限制于某一个特定位置有可以忽略不计的矢状面内微小伸屈运动,头部虽存在一定范围的仰屈度变化,颈椎中立位状态下颈椎与头部这些变化不影响突出颈椎间盘体积、C2-6 Cobb角及颈椎(C3-C7)曲率等参数测量的精准度与可靠性。

BACKGROUND:Cervical neutral position magnetic resonance imaging is widely used for the diagnosis and treatment of cervical spondylotic myelopathy.However,it is not possible for patients to maintain the exact same position of the head and neck during repeated cervical magnetic resonance imaging examinations.The cervical spine undergoes minor flexion and extension movements in the sagittal plane,and the head may have a certain degree of variation in flexion and extension.Whether these changes in the neutral position of the cervical spine affect the volume of cervical discs herniation and cervical curvature is unclear.OBJECTIVE:Using artificial intelligence-assisted measurement,this study aimed to analyze the accuracy and reliability of magnetic resonance imaging examinations for measuring the volume of cervical discs herniation and cervical curvature in patients with cervical spondylotic myelopathy undergoing two consecutive cervical neutral positions in the short term.METHODS:A retrospective study was conducted on patients with cervical spondylotic myelopathy who underwent conservative treatment and underwent two consecutive cervical magnetic resonance imaging examinations within three months between June 2012 and June 2023.We proposed the use of occipitalthoracic distance and occipital-thoracic angle to evaluate the variation in flexion and extension of the head in the neutral position of the cervical spine.Based on the changes in occipital-thoracic angle,patients were divided into occipital-thoracic angle increase group and occipital-thoracic angle decrease group.Cervical discs herniation volume,C2-6 Cobb angle,and cervical(C3-C7)curvature were measured using artificial intelligence-assisted measurement software.Normal distribution data were represented by mean±SD,while non-normal distribution data were represented by the median(interquartile range).Spearman’s rank correlation coefficient was used to analyze the correlation between changes in Cobb angle,cervical(C3-C7)curvature,and cervical discs herniation volume.RESULTS AND CONCLUSION:(1)A total of 104 patients and 326 cervical discs herniation were included in the study.There were 47 patients in the occipitalthoracic angle increase group and 57 patients in the occipital-thoracic angle decrease group.(2)Extension and flexion index of the head:There were no significant differences in occipital-thoracic distance and occipital-thoracic angle during the initial diagnosis and follow-up examination.The variation of occipitalthoracic distance was 0.035(3.23)mm,and the variation of occipital-thoracic angle was-0.31(3.28)°.The deviation range of occipital-thoracic distance and occipital-thoracic angle was small,and there was no significant correlation.(3)Cervical curvature index:There were no significant differences in C2-6 Cobb angle and C3-C7 curvature during the initial diagnosis and follow-up examination.There were no significant differences in C2-6 Cobb angle and C3-C7 curvature between the occipital-thoracic angle increase group and occipital-thoracic angle decrease group.(4)There was no significant difference in volume of cervical discs herniation during the initial diagnosis and follow-up examination.There was no significant difference in volume of cervical discs herniation between the occipital-thoracic angle increase group and occipital-thoracic angle decrease group.There was no significant correlation between the change of cervical discs herniation volume and the change of C2-6 Cobb angle and the cervical(C3-C7)curvature.(5)These results indicate that in the neutral position of the cervical spine,there were negligible minor flexion and extension movements in the sagittal plane,and the head was limited to a specific position.Although the head has a certain range of flexion and extension variation,it does not affect the accuracy and reliability of parameters including cervical discs herniation volume,C2-6 Cobb angle,and cervical(C3-C7)curvature.