动态增强MRI对早期类风湿性关节炎的诊断价值

The Value of Dynamic Enhanced MRI in Early Stage Rheumatoid Arthritis

目的探讨动态增强MRI对早期类风湿性关节炎(RA)的诊断价值。方法随访临床明确诊断为早期RA患者30例纳入研究,另选20例志愿者作对照。所有病例均进行MRI平扫、动态增强及增强扫描检查,观察分析MRI异常征象及时间-信号强度曲线(TIC),测量滑膜最大强化率(ERmax)、最大上升斜率(Slopemax)和滑膜厚度。采用秩和检验及t检验分析比较两组间量化参数的差异,用ROC曲线下面积评价各参数的诊断价值。结果早期RA动态增强扫描后关节囊增厚滑膜、血管翳及腱鞘增厚滑膜组织明显强化,不同部位滑膜、血管翳显示不同程度和范围的增厚,其TIC曲线25例呈上升平台型,5例呈延迟上升型;对照组TIC曲线均呈缓慢略上升平台表现。早期RA与正常对照组ERmax值分别为(269.07±112.81)%、(39.24±34.42)%,Slopemax值分别为399.57±392.95、57.30±24.53,滑膜厚度分别为(3.29±0.78)mm、(1.37±0.62)mm。两组间ERmax、Slopemax和滑膜厚度的差异均有统计学意义(Z值分别为-5.32、-5.18,t值为8.960)。ERmax、Slopemax和滑膜厚度受试者工作特征(ROC)曲线下面积分别为0.991、0.978、0.966,以最大约登指数为最佳诊断切入值,ERmax、Slopemax和滑膜厚度诊断早期RA的敏感性分别为100%、90.0%和83.3%,特异性分别为53.3%、100%和86.7%。结论动态增强MRI扫描的TIC曲线及ERmax、Slopemax和滑膜厚度等量化指标,结合MRI早期征象可全面反映早期RA的病理改变,在早期RA诊断中有重要意义。

Objective To investigate the value of dynamic contrast enhanced MRI （DCE MRI） in early stage rheumatoid arthritis （RA） in wrist. Methods 30 clinical diagnosed as early stage RA after 3 to 6 months follow up and 20 volunteers were selected to undergo plain MRI, enhanced MRI, dynamic contrast enhanced MRI examination. The time intensity curve （TIC） and MRI findings were analyzed. The maximum enhancement ratio （ER,max）, maximum rise slope （Slopema,） and thickening of synovial membrane were measured on DCE MRI. The ROC curve analysis was used to test the diagnostic power of all DCE MRI parameters （ER Slope max） and thickening of synovial membrane. Results Synovial membrane in the early stage RA was observed enhanced to varying degree after the administration of gadolinium. 25 cases of TIC in DCE MRI were I1 type curve （platform type） and 5 cases were Ⅲ type curve （delay up） in the early stage RA. The ERmax of synovial membrane in RA and control group was （269.07±112.81 ） % and （39.24±34.42 ） % respectively. The Slopemax of synovial membrane in RA and control group was 399.57±392.95 and 57.30±24.53 respectively. The synovial membrane thickening of RA and control group was （ 3.29±0.78 ） mm and （ 1.37±0.62） mm respectively. The biggest area under the ROC curve of the ERmax, Slopemax and synovial membrane thickening was 0. 991,0. 978 and 0.966 respectively. The ERmax, Slopmax and synovial membrane thickening in diagnosing the early stage RA yielded sensitivity respectively of 100%, 90.0% and 83.3%. specificity respectively of 53.3%, 100% and 86.7%. Conclusion The TIC and quantitative parameters of DCE MRI （ including ER Slopemax ） and MRI abnormal findings can reflect the all pathologic process in the early stage RA and are valuable in diagnosing the early stage RA.