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

目的：通过对腕部动态增强磁共振成像的分析，探讨类风湿关节炎(RA)及其相关疾病的疾病活动性。材料与方法：根据临床资料，将38例RA患者分为活动期RA组29例，非活动期RA组5例，非活动期RA组4例。选择A2 cm厚的冠状面覆盖整个手部，注射对比剂后每隔3~4s扫描一次快速SPGR图像。在阳性强化区域可获得动态曲线。结果：活动期RA组早期增强率高于非活动期组，两组PEI-60比较差异有统计学意义(P<0.01)。PEI-60与CRP呈显著正相关，相关系数为0.45(p&lt；0.01)。基于该参数的功能图像可用于对局部疾病活动度的直观评估。结论：动态磁共振成像可用于评估RA的疾病活动度。然而，这种方法的一个主要问题是难以对多个节理进行评价。我们计划利用动态磁共振成像进行进一步的研究，以评估早期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..