Moon Kyu Pill, Suh Kuen Tak, Lee Jung Sub
Department of Orthopedic Surgery, Busan National University School of Medicine, Busan, Korea.
Asian Spine J. 2009 Jun;3(1):16-20. doi: 10.4184/asj.2009.3.1.16. Epub 2009 Jun 30.
A retrospective study
This study examined the reliability of the MRI findings in detecting symptomatic extraforaminal disc herniation in the lumbar spine.
There are no reports of the characteristics and reliable MRI findings of extraforaminal disc herniation.
Thirty age-and gender-matched asymptomatic volunteers and 30 patients with symptomatic extraforaminal disc herniation, who underwent surgery between March 2006 and Dec 2008, were enrolled in this study. All subjects underwent spinal MRI. The following parameters were evaluated: the presence or absence of focal eccentricity of the disc, change in the diameter of the nerve root, and displacement of the nerve root at the extraforaminal zones. Radiologic studies were reviewed blindly and independently by 3 spine surgeons.
The overall agreement in determining the presence or absence of a symptomatic extraforaminal disc herniation between the three reviewers was 89.4% (161/180). The consensus showed focal eccentricity of the disc in 33 cases (55%), a change in diameter in the nerve root in 31 cases (51.7%), and a displacement of the nerve root in 23 cases (38.3%). An assessment of the paired intraobserver and interobserver reliability revealed mean Kappa statistics of 0.833 and 0.667 for focal eccentricity of the disc, 0.656 and 0.556 for a change in the diameter of the nerve root, and 0.669 and 0.020 for a displacement of the nerve root, respectively.
There are three possible MRI findings that can be used to determine the presence or absence of symptomatic extraforaminal disc herniation. Among these MRI findings, focal eccentricity of the disc was found to be the most reliable.
一项回顾性研究
本研究旨在探讨磁共振成像（MRI）检查结果在检测腰椎椎间孔外椎间盘突出症中的可靠性。
目前尚无关于椎间孔外椎间盘突出症特征及可靠MRI表现的报道。
选取2006年3月至2008年12月间接受手术治疗的30例年龄和性别匹配的无症状志愿者以及30例有症状的椎间孔外椎间盘突出症患者纳入本研究。所有受试者均接受脊柱MRI检查。评估以下参数：椎间盘是否存在局灶性偏心、神经根直径变化以及椎间孔区神经根移位情况。由3位脊柱外科医生对影像学研究进行盲法独立评估。
三位评估者在判断是否存在有症状的椎间孔外椎间盘突出症方面的总体一致性为89.4%（161/180）。共识显示，33例（55%）存在椎间盘局灶性偏心，31例（51.7%）神经根直径有变化，23例（38.3%）神经根有移位。对观察者内和观察者间可靠性的配对评估显示，椎间盘局灶性偏心的平均Kappa统计值分别为0.833和0.667，神经根直径变化的平均Kappa统计值分别为0.656和0.556，神经根移位的平均Kappa统计值分别为0.669和0.020。
有三种可能的MRI表现可用于判断是否存在有症状的椎间孔外椎间盘突出症。在这些MRI表现中，椎间盘局灶性偏心被认为是最可靠的。
