Magnetic Resonance Imaging in Rheumatoid Arthritis and Related Disorders: Assessment of Disease Activity Using Dynamic Magnetic Resonance Imaging

目的：我们试图通过分析手腕动态对比增强MR成像来评估类风湿性关节炎（RA）和相关疾病的疾病活动性。材料与方法：38例患者根据临床资料分为活动性ra组（n=29）、非活动性ra组（n=5）和非活动性ra组（n=4）。选择A2 cm厚冠状面覆盖整个手，注射造影剂后立即每3-4秒快速spgr图像。在阳性增强区域得到动态曲线。计算0-60秒之间的正增强积分（动态曲线与连接动态曲线两点的直线之间的面积）（PEI-60），并以此参数生成功能图像。结果：ra活动组早期增强率明显高于无活动组，两组间PEI-60值差异有统计学意义（活动组34.6±18.6，无活动组14.3±12.8,p<0.01）。PEI-60与CRP呈显著相关，相关系数为0.45 （p<0.01）。基于此参数的功能图像可用于局部疾病活动的视觉评估。结论：动态磁共振成像研究可用于评估RA的疾病活动性。然而，该方法的一个主要问题是难以对多个关节进行评估。我们正计划开展进一步的研究，使用动态磁共振成像来评估早期RA的治疗结果。

Objectives: We attempted to evaluate disease activity in rheumatoid arthritis (RA) and related disorders by analyzing the dynamic contrast-enhanced MR imaging of the wrist.Materials and Methods: 38 patients were classified into active-RA group (n=29), inactive-RA group (n=5), and non-RA group (n=4) based on the clinical data. A2 cm-thick coronal section was selected to cover the entire hand, and fast-SPGR images were obtained every 3-4 seconds immediately after contrast injection. Dynamic curves were obtained in the regions of positive enhancement. Positive enhancement integral (area between the dynamic curve and straight line connecting two points of the dynamic curve) between 0-60 seconds was calculated (PEI-60) and a functional image was made based on this parameter.Results: Rate of early enhancement of active-RA group was greater than that of inactive group, and there was significant difference in PEI-60 between these two groups (active group 34.6±18.6, inactive group 14.3±12.8, p<0.01). PEI-60 and CRP were significantly correlated with correlation coefficient of 0.45 (p<0.01 ). A functional image based this parameter can be used for visual assessment of the local disease activity.Conclusion: Dynamic MR imaging study can be used to assess disease activity in RA. However, a major problem of this method is the difficulty in evaluation of the multiple joints. We are planning to conduct further studies using dynamic MR imaging for the assessment of treatment outcome in early stage of RA..