膝关节色素沉着绒毛结节性滑膜炎的MR诊断价值

目的：分析膝关节色素沉着绒毛结节性滑膜炎（ pigmented villonodular synovitis ，PVNS）的MRI影像表现，以提高对该病的认识和诊断水平。方法回顾性分析14例经病理证实的膝关节PVNS的MRI影像表现，并与病理结果进行对照。结果14例中2例为局限型，12例为弥漫型。局限型主要表现为单发结节影，边缘光整；弥漫型表现为滑膜弥漫增生呈“海绵垫状”、“菜花状”，T1 WI呈中等或稍低信号影，T2 WI呈等或稍高信号影为主，其内见单发或多发大小不等结节影，T1 WI、T2 WI呈低信号影。3例增强后病灶呈不均匀强化。7例伴有软骨及软骨下侵蚀，周围见低信号硬化缘。6例见骨髓水肿，呈长T1长T2改变。关节腔积液11例，其中2例出现液-液平面。结论膝关节PVNS的MR表现具有一定特征性，对该病的诊断及鉴别诊断具有重要价值。

The value of MRI in diagnosing pigmented villonodular synovitis of knee joint

Objective Analyzing MRI manifestations of pigmented villonodular synovitis （PVNS） to improve the diagnosis ability and understading of the disease .Methods Imaging features of 14 cases of patients with pigmented villonodular synovitis confirmed by surgi-cal pathology were analyzed retrospectively and compared with pathological findings .Results 2 of 14 cases were localized form and 12 cases were diffuse form.The localized form of PVNS in MRI appeared solitary nodule and mass with a well-defined margin.The diffuse form showed extensive synovial proliferation like foam-rubber cushion or cauliflower .In MRI,the proliferative synovial membrane displayed isointensity or hypointensity on T1WI,mainly isointensity or hyperintensity on T2WI,villar nodular with hypointensity T1 and T2 signal were observed in the synovial membrane ,which obviously enchanced after contrast administration in 3 patients.Erosion of cartilage and bone in 7 cases,and the low signal hardened edges were showed .Bone marrow edema was found in 6 cases,which manifested long T1 long T2.Different degrees of joint ef-fusion were revealed in 11 patients,among which 2 cases appeared liquid-liquid delamination.Conclusion The MRI findings of PVNS of the knee joint have certain characteristic ,which are correlated with histopathology closely ,therefore can contribute to the differentiation with other disease.