基于磁共振分级的膝关节骨关节炎关节软骨T2图

摘要

目的 探讨T2图在膝关节骨关节炎关节软骨成像的表现与运用.方法 对38例健康组和53例膝关节骨关节炎(OA)患者进行西安大略和麦克马斯特大学骨关节炎指数(WOMAC)评分和胫股关节软骨矢状位T2图成像,测量软骨10个亚区的T2值.OA 组另行矢状位脂肪抑制三维快速扰相梯度回波成像和修订的全器官磁共振成像评分(WORMS),按修订的磁共振Recht分级分成轻度(OA1)和重度(OA2)两组,比较各亚区T2值在健康组、OA1和OA2组间的差异、T2值与WORMS及WOMAC评分的相关性和T2值测量的观察者内和观察者间信度.结果 健康组、OA1组和OA2组胫股关节软骨各亚区的T2值分别为43.9-53.6、41.1-55.0和45.6-56.1 ms.OA2组T2值在股骨内侧中区、胫骨内及外侧中区高于健康组,在股骨内侧中区、胫骨内侧前及中区高于OA1组(P<0.05).除股骨外侧后区外,OA组的T2值与WORMS评分呈正相关(R=0.307-0.811,P<0.01),与WOMAC总分及亚领域评分无相关性.除OA组的胫骨外侧前区观察者间外,T2值测量在观察者内和观察者间具有可信度(R>0.740,P<0.05).结论 T2地图能区分基于磁共振分级的OA严重程度,是膝关节OA病情监测的敏感手段.%Objective To evaluate T2 mapping of articular cartilage in knee osteoarthritis (OA). Methods Totally 38 healthy subjects ( group H) and 53 OA patients received scoring with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and underwent T2 mapping of tibiofemoral articular cartilages. The T2 values in 10 subregions of the cartilages were measured. Patients in the OA group were further divided into OA1 group and OA2 group using the modified Magnetic Resonance Recht Grading System. In OA group, the fat-suppressed three-dimensional fast spoiled gradient echo MRI was performed to obtain the modified Whole-Organ Magnetic Resonance Imaging Score (WORMS). The differences of T2 values among group H, group OA1, and group OA2 were compared. The correlation between T2 value and WORMS/WOMAC scores was analyzed. The intra- and inter-observer reproducibility of measurement was calculated. Results The T2 values in all the subregions ranged 43.9-53.6ms in group H, 41.1-55.0 ms in group OA1, and 45.6-56. 1 ms in group OA2. T2 values in group OA2 were significantly higher in central medial femoral subregion, central medial, and lateral tibial subregions compared with group H, also significantly higher in central medial femoral subregion, anterior and central medial tibial subregions compared with group OA1 ( P ＜ 0.05 ). T2 values were significantly correlated with WORMS scores (R= 0. 307-0. 811, P ＜ 0.01 ) except in posterior lateral femoral subregion, but not with WOMAC scores. The correlation coefficients for intra- and inter-observer measurement showed good reproducibility (R ＞ 0. 740, P ＜ 0. 05 ) except in anterior lateral tibial subregion for inter-observer of measurement. Conclusion T2 mapping can differentiate the OA severity of knee cartilage using a magnetic resonance staging, and therefore can be a sensitive technique for monitoring the severity of OA.