膝关节盘状半月板及其损伤的MRI诊断

Diagnostic value of magnetic resonance imaging on discoid meniscus of knee joint

目的探讨盘状半月板及损伤的MRI表现及诊断标准。方法回顾性分析经手术或关节镜证实的50例盘状半月板的MRI图像表现。结果本组50例均为外侧盘状半月板,39例为厚板型,11例为楔型,44例合并不同程度损伤,损伤率达88%。冠状位MR I上外侧半月板体部宽度与同层面外侧胫骨平台的比率超过50%,矢状位连续3层或3层以上盘状半月板前后角相连形成“蝴蝶结”样改变,为盘状半月板诊断的可靠依据。结论MR I是检查盘状半月板的首选方法,冠、矢状位可准确诊断盘状半月板。

Objective To investigate the MRI manifestation of discoid meniscus and the diagnosis criteria of MRI. Methods 50 cases of discoid meniscus proved by arthroscopy and operation were analyzed retrospectively. Results All discoid menisci were lateral menisci. Besides ,39 cases were classified as slab type, 11 cases were wedge type, and 44 cases were combination different injury, the ratio of injury is 88%. On the coronal plane, through the tibial intercondylar emience, the ratio of the width of meniscus to that of tibial plateau were over 50%. On the sagital plane, there were consecutive 3 layers or more showed ＂butterfly＂ change, which is the reliable witness to diagnose the dicoid meniscus. Conclusion Sagital and coronal MRI can be used for the accurate diagnosis of discoid meniscus and MRI is the first choice to diagnose the discoid meniscus.