膝关节半月板MRI与病理学对照研究

A comparative study of the meniscus of the knee joint using MRI correlated with pathology

目的探讨膝关节半月板ＭＲＩ信号改变的病理组织学基础。方法搜集因各种原因作膝关节以上离断的１２个肢体，以及完整摘除的１个半月板，共计２５个半月板。对这些半月板作ＭＲ成像与病理组织切片对照。结果２５个半月板中，ＭＲＩ呈均匀低信号１３个，有不达关节面的球形、片状、条状高信号１０个，有２个半月板呈现达关节面的高信号。病理组织学见ＭＲ呈均匀低信号的１３个半月板中有１０个为正常纤维软骨组织，２个可见钙化，１个有纤维脂肪变性；１０个不达关节面的高信号的半月板中，病理组织学上有７个可见程度不同的脂肪细胞浸润、纤维素样变性、厚壁血管增生及脂肪细胞融合成团等退行性改变，１个为正常，２个有软骨基质水肿；２个ＭＲＩ信号显示撕裂的半月板除大体标本可见裂口外，病理组织学上可见纤维脂肪组织取代了纤维软骨，并有玻璃样变和瘢痕形成。结论半月板内ＭＲＩ信号改变与病理组织学改变基本一致。但ＭＲ信号正常时也可以存在半月板钙化。不达关节面的半月板高信号形成原因很多，软骨基质水肿也可能是其形成原因之一。

Purpose To study the relationship between MR imaging features of meniscus and its pathology. Methods MR imaging and tissue section were performed in 25 specimen of meniscus including 12 legs amputated above knee joint and one surgical specimen. Results 13/25 showed low signal intensity of MR, 10/25 images with linear or globular high signal intensity without reaching the surface of meniscus, 2/25 with high signal intensity reaching surface of meniscus. Histologic findings of 10/13 with low signal intensity were normal, 2/13 had calcification, 1/13 had degeneration. 7/10 with high signal intensity revealed fibroid degeneration and fatty infiltration, 2/10 showed swelling of cartilage matrix , 1/10 was normal. Two cases with high signal intensity had tears, hyaline degeneration and scar formation. Conclusion Pathologic findings and MR imaging have a good positive relevance in most cases. However, even with normal signal intensity of MR in some cases calcification of meniscus was demonstrated. Cartilage matrix swelling may be one of the causes contributing to high signal intensity that does not reach the joint surface.