正常及滑膜病变者膝关节MR间接造影检查

目的：探讨正常及滑膜病变者膝关节间接MR造影表现,评估MR间接膝关节造影的价值。方法：25例成年人共25个膝关节,正常组20例,临床拟诊膝关节滑膜病变者5例。所纳入的MR扫描序列为矢状位、轴位3D-SPGRT1WI及矢状位SET1WI脂肪抑制序列。对比剂钆喷替酸葡甲胺（Gd-DTPA）,注射剂量0.2mmol/kg。扫描时间窗为：平扫、经肘静脉注入对比剂后立即、2h及4h。选择矢状位髌上滑膜囊为感兴趣区,测量其内关节液信号强度,计算其与腘窝后方空气本底的信号强度比。统计分析正常及滑膜病变者关节液各时段强化差异。结果：正常组经肘静脉注入对比剂后2h,髌上滑膜囊内关节液显著强化,4h后其信号强度比与平扫无显著差异。滑膜病变组中,经手术证实3例为滑膜结核,2例为慢性非特异性滑膜炎,注入对比剂后4h关节液强化程度高于2h,平扫及增强后立即扫描无显著差异。结论：滑膜正常者膝关节腔内对比剂吸收较快,而滑膜病变者关节液强化延迟。MR间接膝关节造影在滑膜强化期能很好显示病变滑膜的形态改变并提供血供变化信息,在关节液强化期可显示关节内结构的改变。

Indirect MR arthrography of knee jojnt with normal and abnormal synovinm

Objective： To investigate the characteristics of indirect MR arthrography in knee joint with normal and abnormal synovium and to evaluate its feasibility. Materials and Methods： Twenty-five aduhs（25 knee joints）, twenty of them were asymptomatic volunteers, the other 5 were diagnosed as synovial disease clinically. All subjects underwent transverse T1WI 3D-SPGR, sagittal T1WI 3D-SPGR and sagittal SE T1WI MR images of the knee joint before, immediately after, 2 hours after and 4 hours after intravenous administration of contrast medium respectively. The suprapatellar bursa was selected as the ROIs of the joint cavity. Its signal intensity was measured by using oval ROIs and their ratio to the background IS of the air adjacent to the popliteal fossa was calculated. The differences of the enhancement characteristic between the normal and abnormal synovial fluid in different time window were analysed statistically with SPSS 13.0. Results： In 20 normal knee joints, the fluid within the suprapatellar synovial cavity appeared markedly enhanced 2 hours after I.V. There was no difference between the 4 hours after injection and plain scan. Among the 5 knee joints with diseased synovium, 3 were confirmed as synovial tuberculosis, 2 were confirmed as the nonspecific synovitis. They appeared as more remarkable enchancement 4 hours injection of contract agent than 2 hours after injection, however, there was no significant difference between the immediate scan after I.V and the plain scan. Conclusion： The washout of contrast medium in the normal synovial cavity is faster than the diseased synovial cavity. The fluid in the diseased synovial cavity appeared as delayed enhancement. The indirect MR arthrography has the advantage to demonstrate the abnormality of the synovium during the synovial enhancement and can provide some information about its blood supply.