前交叉韧带损伤:MRI多征象分析

目的明确MRI对各种前交叉韧带(ACL)损伤征象的诊断价值.方法回顾分析139个经关节镜证实的膝关节MR图像,包括52个损伤的ACL和87个完好的ACL.在不告知关节镜结果的条件下,2名放射医生共同对5个ACL损伤直接征象和13个间接征象进行评价.结果在评价的5个直接征象中,ACL不连续和ACL走行异常均具有相对高的诊断敏感性、特异性以及阳性试验似然比(LR );在评价的13个间接征象中,大多数具有相对高的特异性和低的敏感性,其中"对吻性"骨挫伤、Notch征、胫骨前移位、以及外侧半月板后角裸露等4个征象具有相对高的LR .结论 ACL损伤的直接征象为诊断主要依据,以ACL不连续和ACL走行异常最具诊断价值;ACL损伤的间接征象具有辅助诊断意义,其中"对吻性"骨挫伤、Notch征、胫骨前移位、以及外侧半月板后角裸露等4个征象最有价值.

MR imaging of anterior cruciate ligament injury: evaluation with multiple signs

Objective To assess the diagnostic value of various signs of magnetic resonance imaging (MRI) for anterior cruciate ligament (ACL) injury. Methods MRI of 139 knee joints followed by arthroscopy were retrospectively evaluated. There were 52 knees with ACL injuries and 87 with intact ACL. Unknowing the results of arthroscopy, two radiologists evaluated all images for the presence of 5 primary signs and 13 secondary signs by consensus. Results Among the 5 primary signs, discontinuity of ACL and abnormal contour of ACL had relative higher sensitivity, specificity, and likelihood ratio of a positive test (LR+) value. Most of the secondary signs, however, had relative high specificity but low sensitivity. The following 4 secondary signs, "Kissing" bone bruise, Notch sign, anterior tibial translation, and uncovered posterior horn of lateral meniscus, had higher LR+ value. Conclusion Primary signs were the main clues for diagnosing ACL injuries, and the two most valuable signs were discontinuity and abnormal contour of ACL. Secondary signs were only for assistant diagnosis and "kissing" bone bruise, Notch sign, anterior tibial translation, and uncovered posterior horn of lateral meniscus were most helpful.