Aboelmagd S M, Low S B, Cahir J G, Loveday D, Marshall A T, Teh J, Vaughan P, Grainger A, MacGregor A, Toms A P
Department of Radiology, Royal Devon and Exeter NHS Trust, UK.
Department of Radiology, Norfolk & Norwich University Hospital, UK.
Clin Radiol. 2022 Jun;77(6):e449-e457. doi: 10.1016/j.crad.2022.02.009. Epub 2022 Mar 30.
To define and test the inter- and intra-rater reliability of a grading system for staging osteoarthritis (OA) of the ankle with magnetic resonance imaging (MRI) (Norwich Osteoarthritis of the Ankle MRI Score, NOAMS).
The MRI features to be included in the score were defined by a multidisciplinary expert panel through a Delphi process. An anonymised randomised dataset of 50 MRI studies was created from patients with concurrent plain radiographs to include 10 ankles of each of the Kellgren-Lawrence grades 0 to 4. Two experienced musculoskeletal radiologists and two trainees scored each ankle MRI twice independently and blinded to the plain radiographs.
The inter-rater kappa coefficient of agreement for cartilage disease was 0.88 (95% confidence interval [CI]: 0.85, 0.91) for experienced raters and 0.71 (95% CI: 0.67, 0.76) for trainees. Inter-rater agreement for subchondral bone marrow oedema and cysts varied from 0.73 to 0.82 for experienced raters and from 0.63 to 0.75 for trainees with lowest 95% CI of 0.48 and 0.63. When bone marrow lesions were combined into a total joint score the level of agreement increased to between 0.88 and 0.97 with lowest 95% CI of 0.86. Combining cartilage zone scores did not increase the reliability coefficients.
An expert panel considered that cartilage degradation and subchondral bone marrow lesions were the most important features for staging the severity of ankle OA on MRI. Experienced observers can grade the severity of ankle OA on MRI with a clinically useful high degree of reproducibility.
定义并测试用于踝关节骨关节炎（OA）分期的磁共振成像（MRI）分级系统（诺维奇踝关节骨关节炎MRI评分，NOAMS）的评分者间及评分者内信度。
通过德尔菲法，由多学科专家小组确定评分中包含的MRI特征。从同时有X线平片的患者中创建了一个包含50项MRI研究的匿名随机数据集，其中Kellgren-Lawrence分级0至4级的踝关节各10个。两名经验丰富的肌肉骨骼放射科医生和两名实习医生对每个踝关节MRI进行两次独立评分，且对X线平片结果不知情。
对于软骨疾病，经验丰富的评分者的评分者间kappa一致性系数为0.88（95%置信区间[CI]：0.85，0.91），实习医生为0.71（95%CI：0.67，0.76）。对于软骨下骨髓水肿和囊肿，经验丰富的评分者的评分者间一致性在0.73至0.82之间，实习医生在0.63至0.75之间，最低95%CI分别为0.48和0.63。当将骨髓病变合并为全关节评分时，一致性水平提高到0.88至0.97之间，最低95%CI为0.86。合并软骨区域评分并未提高信度系数。
专家小组认为，软骨降解和软骨下骨髓病变是在MRI上对踝关节OA严重程度进行分期的最重要特征。经验丰富的观察者能够以临床可用的高再现性对MRI上踝关节OA的严重程度进行分级。
