比较磁共振成像和病理对大鼠Ⅱ型胶原诱导性关节炎早期关节病变的诊断价值

目的 建立Ⅱ型胶原诱导性大鼠关节炎模型(CIA),结合病理改变研究磁共振成像(MRI)检测对早期类风湿关节炎的诊断价值.方法 用牛Ⅱ型胶原和不完全弗氏佐剂联合皮内注射免疫Wistsr大鼠,制作关节炎模型;免疫后不同时期分别采用普通X线摄片、1.5T磁共振仪进行双踝关节平扫加增强扫描以及病理组织学等方法 进行大鼠踝关节病理学特征分析.结果 CIA实验组大鼠免疫14 d后,其关节指数(AI)显著增加,28 d AI增加达到最高(3.6±1.0),抗Ⅱ型胶原抗体水平较对照组明显高(P<0.001).根据病理学分析CIA成模率为93.3%.MRI平扫加增强显示有12只出现异常征象,敏感性85.7%,特异性100%,与病理诊断呈正相关(r=0.5345,P<0.05).X线有4只出现关节软组织肿胀,MRI较X线检出率高(P=0.008).结论 MRI对早期关节滑膜炎、滑膜增生、血管翳等病理学的诊断生成方面有明显优势.

Study of the diagnostic value of magnetic resonance imaging for early arthropathy of collagen-induced arthritis model

Objective To establish the rat model of collagen-induced arthritis and study the diagnostic value of MRI for early RA by comparing to pathological changes. Methods Thirty Wistar rats were randomly divided into normal groups and experimental groups.Fifteen rats of the experimental groups were immunized with type Ⅱ collagen and Freund's Adjuvant Incomplete. At the scheduled days, the selected rats of both experimental and normal groups underwent X-ray, 1.5T MR scan plus enhancement and histological analysis. Results Arthritis Index increased on the 14th day after immunization and reached the peak on the 28th day in the experimental group, the positivity of Anti-CⅡ antibody was significantly different from the normal group.The experiemental model was established in 93.33% of all rats. The enhanced MRI showed that 12 (12/15) rats presented with abnormal signs . The sensitivity of MRI was 85.71% and the specificity was 100%. There was no significant correlation could be found between MRI and histological changes X-ray revealed soft tissue swollen in 4 (4/15) rats, which showed that MRI had higher sensitivity in detecting abnormal signs of arthritis than X-ray. Conclusion MRI may be used in the early diagnosis of early RA.