膝关节色素性绒毛结节滑膜炎的MRI与病理对照研究

MRI Diagnosis and Pathologic Correlation of Pigmented Villonodular Synovitis of the Knee Joint

目的 :探讨膝关节色素性绒毛结节滑膜炎 (PVNS)的MRI诊断价值及其病理基础。方法 :回顾性分析 10例经病理证实的膝关节PVNS的MRI、X线平片影像资料 ,比较和评价膝关节PVNS的MRI信号特点 ,关节内结构侵犯、关节外侵犯和骨质侵蚀等征象。结果 :10例膝关节PVNS中 ,8例具有典型的含铁血黄素沉着 ,MRI可以准确显示X线平片难以显示的骨质侵蚀、关节内软骨和韧带侵蚀以及关节外侵蚀的范围。PVNS的MRI信号强度可分为 3种类型 :Ⅰ型 ,T1WI高信号 ,T2 WI等信号或高信号 ;Ⅱ型 ,T1WI等信号或低信号 ,T2 WI低信号 ;Ⅲ型 ,T1WI等信号或低信号 ,T2 WI高信号。每种类型分别对应其病理发展过程中的早、中及晚期病理表现。结论 :MRI在膝关节PVNS诊断中具有很高的价值 ,绒毛结节内含铁血黄素沉着所致的T1WI低信号、T2 WI低信号为其特征性改变 ,但并不贯穿PVNS全过程。快速小角度激发扫描优于自旋回波和快速自旋回波扫描。

Objective:To evaluate the diagnostic value of MRI in pigmented villonodular synovitis (PVNS) of the knee joint and the pathologic basis of MRI features.Methods:MRI and radiographic features in 10 patients with pathologically-proved PVNS of the knee joint were retrospectively analyzed.MRI signal features,the involvement of intra-and extra-articular structures and bony erosion were evaluated.Results:Of 10 cases,iso-and low signal on T 1WI and T 2WI,typical hemosiderin deposition was seen in 8.Bony erosion,involvement of intra-articular cartilage and ligament and the invasion of extra-articular structures,which were hardly displayed on plain film were well demonstrated on MRI.MRI features of PVNS was divided into 3 types:Type Ⅰ:high signal on T 1WI,intermediate or high signal on T 2WI.Type Ⅱ:intermediate or low signal on T 1WI,low signal on T 2WI.Type Ⅲ:intermediate signal on T 1WI and high signal on T 2WI.Each type corresponded to its early,middle and late pathologic stage of the disease.Conclusion:MRI is of great value in diagnosing PVNS of the knee joint.The intermediate to low signal on T 1WI and low signal on T 2WI,which are produced by hemosiderin deposition within villonodules,is the characteristic sign on MRI,although it does not always appear through the whole course.Fast low-angle shot technique is superior to spin echo and turbo-spin echo for evaluation pigmented villondular synovitis.