色素沉着绒毛结节性滑膜炎的MRI与病理对照分析

MRI-pathologic correlation of pigmented villonodular synovitis

目的 研究色素沉着绒毛结节性滑膜炎 (PVNS)MRI表现的病理基础及其在扩散加权像 (DWI)上异常信号改变的机制。方法 分析 7例PVNS的MRI表现 ,计算DWI上异常信号灶的表观扩散系数 (ADC) ,并与手术病理结果进行对照分析。结果 7例PVNS中弥漫型 5例 (膝关节4例 ,肩关节 1例 )。MRI主要表现为关节滑膜广泛增生 ,呈长T1 、长T2 信号 ,其内见含铁血黄素沉着 ,呈长T1 、短T2 信号 ;4例见膝关节腔积液 ,呈长T1 、长T2 信号 ;半月板破坏 3例 ,前、后交叉韧带破坏 2例 ,呈结节状长T1 、长T2 信号 ;4例见关节内软骨和邻近骨质明显破坏 (膝关节 3例 ,肩关节 1例 ) ,1例股骨骨质呈小囊状破坏。局限型 2例 (膝关节、髋关节各 1例 ) ,主要表现为滑膜结节状增生 ,其内亦可见含铁血黄素沉着 ,呈长T1 、短T2 信号。 1例见关节腔内少许积液 ,邻近股骨骨质小囊状破坏。DWI上关节积液、滑膜增生及邻近骨质破坏表现为异常高信号 ,其平均ADC值分别为 2 .750× 1 0 - 3mm2 /s,0 .52 2× 1 0 - 3mm2 /s,0 .559× 1 0 - 3mm2 /s。结论 滑膜绒毛结节状增生及其内点状或结节状含铁血黄素沉着是PVNS的典型表现 ,在MRI上具有一定的特征性 ;DWI有助于区分PVNS病变的不同组织成分 ;病变组织的ADC值下降 ,其对鉴别诊断的意义有待进一?

Objective To study MRI features and the pathologic basis of pigmented villonodular synovitis (PVNS) and the corresponding biophysics mechanism of the abnormal signal on diffusion weighted imaging (DWI) Methods MRI findings in 7 cases with PVNS and the ADC value of the lesions on DWI were analyzed, and a comparison with surgical and pathological results was made Results Of the 7 cases, 5 were the diffuse form (4 cases in the knee joint, 1 case in the shoulder joint) The main MRI signs were as follows: the diffused synovial proliferation demonstrated as low signal on T 1WI and high signal on T 2WI; hemosiderin deposition in the thickened synovium was revealed as low signal on both T 1WI and T 2WI; hydrarthrosis of the knee joint was present in 4 cases as low signal on T 1WI and high signal on T 2WI; the involvement of meniscus occurred in 3 cases and cruciate ligament in 2 cases as nodulated low signal on T 1WI and high signal on T 2WI; intra articular cartilage and bony erosion were showed in 4 cases (knee joint in 3 cases, shoulder joint in 1 case); small cystic destruction of the femur occurred in 1 case Two cases were the localized form (1 in the knee joint, the other in the hip joint) It mainly demonstrated as the nodulated proliferation of the synovium and hemosiderin deposition in the thickened synovium, which showed low signal on both T 1WI and T 2WI One case showed hydrarthrosis of the knee joint and small cystic destruction of the femur The hydrarthrosis, synovial proliferation, and bony erosion were demonstrated as high signal lesions on DWI The average ADC values of the three lesions were 2 750×10 -3 mm 2/s, 0 522× 10 -3 mm 2/s, and 0 559×10 -3 mm 2/s, respectively Conclusion The nodulated and villose proliferation of the synovium and hemosiderin deposition within villonodules are the typical MRI signs of PVNS, which is of specific value in the diagnosis DWI can reflect the histologic composition of the tissues comprising the PVNS lesions The ADC values of the lesions usually decrease, and the value of which in differential diagnosis needs further study