Ahn Y, Jeong T S, Lim T, Jeon J Y
Department of Neurosurgery, Gachon University Gil Medical Center, 21, Namdong-daero 774 beon-gil, Namdong-gu, Incheon, 21565, Republic of Korea (South Korea).
Department of Radiology, Gachon University Gil Medical Center, Incheon, South Korea.
Neuroradiology. 2018 Jan;60(1):101-107. doi: 10.1007/s00234-017-1943-7. Epub 2017 Oct 31.
Migrated lumbar disc herniations (LDHs) in the sagittal plane are common. Disc migration grading can be applied as a useful measurement tool in the diagnosis, treatment, and outcome evaluation of migrated LDH. No study has evaluated the reliability of migrated LDH grading. We evaluated the reliability and functionality of the current magnetic resonance imaging (MRI) grading system for migrated LDH.
We assessed a six-level grading system developed based on sagittal MRI and graded according to the direction (rostral and caudal) and degree (low, high, and very high) of disc migration. One-hundred and one migrated LDHs treated with minimally invasive endoscopic discectomy were analyzed independently by two experienced radiologists. Intraobserver and interobserver agreements were assessed by kappa statistics.
The most common migrated LDH grade was grade 4 (30.94%; caudal, low-grade migration). Rostral and caudal migrations were more common in the upper and lower lumbar levels, respectively. Interobserver agreement in the grading of migrated LDH was good at both the first (kappa = 0.737) and second assessment (kappa = 0.657). The intraobserver agreement for reader 1 was very good (kappa = 0.827) and for reader 2 was good (kappa = 0.620).
The current grading system for migrated LDH was found to be reliable and functional with good interobserver and intraobserver agreement. It may be useful in the interpretation of disc migration patterns and outcomes of various minimally invasive surgical procedures.
矢状面移位型腰椎间盘突出症（LDH）很常见。椎间盘移位分级可作为移位型LDH诊断、治疗及疗效评估的有用测量工具。尚无研究评估移位型LDH分级的可靠性。我们评估了当前用于移位型LDH的磁共振成像（MRI）分级系统的可靠性和实用性。
我们评估了一种基于矢状面MRI制定的六级分级系统，并根据椎间盘移位的方向（头侧和尾侧）及程度（低、高和极高）进行分级。由两名经验丰富的放射科医生独立分析101例行微创内镜下椎间盘切除术治疗的移位型LDH。通过kappa统计量评估观察者内和观察者间的一致性。
最常见的移位型LDH分级为4级（30.94%；尾侧，低度移位）。头侧和尾侧移位分别在上腰椎和下腰椎节段更常见。观察者间对移位型LDH分级的一致性在首次评估时良好（kappa = 0.737），第二次评估时也良好（kappa = 0.657）。观察者1的观察者内一致性非常好（kappa = 0.827），观察者2的观察者内一致性良好（kappa = 0.620）。
目前用于移位型LDH的分级系统被发现具有可靠性和实用性，观察者间和观察者内一致性良好。它可能有助于解释椎间盘移位模式及各种微创手术的疗效。
