色素沉着绒毛结节性滑膜炎的MRI表现

目的 探讨色素沉着绒毛结节性滑膜炎(pigmented villonodular synovitis，PVNS)的MRI表现。方法 23例PVNS中膝关节9例，髋关节9例，踝关节3例，肘关节1例，腕关节1例，均经手术和病理证实。23例PVNS均行X线和MR检查，其中4例行CT检查。分析PVNS的影像学表现，着重总结PVNS的MR影像学特点。结果 X线表现：23例均可见关节及软组织肿胀，7例关节内外可出现较致密结节状或分叶状软组织肿块影，19例可见邻近关节骨质侵蚀性小缺损。CT表现：4例中3例可见关节内外结节状或分叶状软组织肿块，增强扫描可见结节样强化，1例CT仅显示关节囊增厚，关节内积液。MRI表现：23例病变部位增生肥厚的滑膜在T1WI上呈中等或中等稍低信号，在T2WI上呈中等稍高信号，其内可见多发散在结节，呈T1WI、T2WI低信号灶；增生肥厚的滑膜在快速梯度回波(FFE)T2WI序列上呈明显结节样低信号。23例病变关节均可见不同程度的关节积液。19例有骨质破坏，表现为凹陷性类圆形骨质缺损，骨缺损区T1、T2WI呈中等信号灶，周围有硬化边，呈T1WI、T2WI低信号。相邻骨髓腔内可见弥漫性反应性水肿灶，呈片状高T2信号。结论 MRI能准确显示PVNS的病变范围和程度，对PVNS有定性诊断价值。

The value of MRI in diagnosing pigmented villonodular synovitis

Objective To evaluate the value of MRI in diagnosing pigmented villonodular synovitis (PVNS). Methods MRI appearance of 23 pathologically proven cases of PVNS was analyzed. Results In 23 patients with PVNS, 9 cases occurred in knee joint, 9 cases in hip, 3 cases in ankle, 1 in elbow, and 1 in wrist. X ray of the 23 patients could only show the joint effusion, and bony erosion was found in 19 cases. CT scan showed joint effusion and bony erosion more clearly than X ray in 4 cases. The typical MRI appearance included intra articular joint effusion and extensive synovial proliferation which led to progressive destruction of cartilage and bone. The pigmented villonodules showed nodular low signal on both T 1WI and T 2WI, especially in FFE/T 2WI. Conclusion MRI is the most effective modality in the diagnosis of PVNS.