膝关节骨性关节炎MR分级可重复性研究

Preliminary study of reproducibility of MR grading for knee osteoarthritis

目的:探讨MR对膝关节骨性关节炎(OA)分级的可重复性。方法:回顾性分析68例(89个膝)膝关节骨性关节炎患者的X线及MR资料,由两名医师独立按照K/L分级及MR分级标准,对膝关节OA进行评级,并按严重程度分为0~4级,对结果进行一致性检验及相关分析。结果:K/L分级0~4级膝关节数8~25个;不同医师MR分级0~4级膝关节数7~31个;两名医师MR分级与K/L分级一致的膝关节数74~76个(83.1%~85.4%)。不同医师间MR分级一致的关节数82个(92.1%);同一医师前后MR分级一致的关节数81~82个(91%~92.1%)。K/L分级与MR分级一致性Kappa值分别为0.812、0.783。两名医师MR分级组间一致性Kappa值为0.897,组内一致性Kappa值分别为0.882、0.897。两名医师的MR分级与K/L分级比较差异无统计学意义(P=0.081和0.117)。结论:膝关节骨性关节炎MR分级具有良好的可重复性,对膝关节OA严重度的评估和研究有指导意义。MR分级有望替代K/L分级作为膝关节OA影像学分级方法之一。

Objective:To investigate the reproducibility of MR grading for osteoarthritis(OA)of knee joints.Methods:The X-ray and MR data of 68 patients(89 knees)with knee OA were analyzed retrospectively.According to the K/L scale and MR grading criteria,knee OA was independently assessed by two attending physicians.The results were divided into 0~4 grades according to knee OA severity,and were then analyzed by the consistency test and correlation analysis.Results:8~25 knee joints were considered to be K/L grade 0~4.7~31 knee joints were considered to be MR grade 0~4 by two different attending physicians.74~76(83.1%~85.4%)knee joints were consistent with MR grading system and K/L scores for two readers.The number of joints with consistent MR grade between the two readers was 82(92.1%).The number of OA joints with intra-observer consistent MR grade for two physicians was 81~82(91%~92.1%).Kappa value of K/L scores and MR grading consistency equaled 0.812 and 0.783.Inter-and intra-observer consistency for MR grading were excellent.Kappa values were 0.882 and 0.897.There was no significant difference between the MR grading and K/L scores(P=0.081,0.117).Conclusions:The MR grading for knee OA has substantial or excellent reproducibility,which is meaningful for the evaluation and research on knee OA severity.It is expected that MR grading will replace K/L scale as one of the radiological evaluation modalities for knee OA.