膝关节腱鞘巨细胞瘤与色素沉着绒毛结节性滑膜炎的MRI分析

目的 分析膝关节腱鞘巨细胞瘤与色素沉着绒毛结节性滑膜炎的MRI表现特点.方法 回顾性分析经手术病理证实的膝关节腱鞘巨细胞瘤11例、色素沉着绒毛结节性滑膜炎25例,均接受MR检查,其中2例色素沉着绒毛结节性滑膜炎患者接受增强扫描.结果 11例膝关节腱鞘巨细胞瘤中,局限型8例、弥漫型3例；9例位于髌韧带附近,1例位于前交叉韧带,1例位于胭窝；与骨骼肌信号相比,病变T1WI呈等低信号,T2WI以混杂高信号为主；关节软骨破坏2例；关节腔积液9例.25例色素沉着绒毛结节性滑膜炎中,局限型4例,弥漫型21例,4例为手术后复发；增生滑膜在T1WI上呈等或稍低信号,T2WI以等或稍高信号为主,其内可见多发结节或肿块样T1WI、T2WI低信号,2例增强扫描明显强化,信号欠均匀；7例增生滑膜突破关节囊进入胭窝,出现胭窝囊肿5例；肌腱、韧带侵犯19例；骨质破坏20例；关节腔积液19例,其中血性积液12例.结论 MR检查对膝关节腱鞘巨细胞瘤与色素沉着绒毛结节性滑膜炎的诊断及鉴别诊断具有重要价值.

MRI diagnosis of giant cell tumor of tendon sheath and pigmented villonodular synovitis of the knee joint

Objective: To observe MRI manifestations of the giant cell tumors of tendon sheath (GCTTS) and pigmented villonodular synovitis (PVNS) of knee joint. Methods: Eleven patients with GCTTS and 25 with PVNS of knee joint confirmed by operation and pathology were retrospectively analyzed. All patients were examined with MR, and 2 of them received contrast enhanced MR scanning. Results: Among 11 cases of GCTTS, 8 were localized lesions,and 3 were diffuse lesions. Lesions located nearby the patellar ligament in 9 patients, anterior cruciate ligament in 1, and popliteal fossa in 1. Compared with the signal of skeletal muscle, the lesions appeared as isointensity or hypointensity on T1WI, and mainly heterogeneous hyperintensity on T2WI. Erosion of the articular cartilage was shown in 2 patients. The joint effusion was detected in 9 patients. Of 25 PVNS, 4 were localized lesions and 21 were diffuse lesions, including 4 recurrent lesions. The proliferative synovial membrane appeared isointensity or hypointensity on T1WI, mainly isointensity or hyperintensity on T2WI, nodular hypointensity T1 and T2 signal were seen within the synovial membrane, which obviously enhanced after contrast administration in 2 patients. The invasion into popliteal fossa invasion of proliferative synovial membrane was seen in 7 patients, and popliteal cyst in 5 patients. The tendon and joint ligments were involved in 19 patients. Erosion of articular cartilage and bony was shown in 20 patients. The joint effusion was detected in 19 patients, including hemorrhagic effusion in 12 patients. Conclusion: MRI findings are of great value for diagnosis and differential diagnosis of GCTTS and PVNS of the knee joint.