MRI多征象分析诊断半月板桶柄状撕裂

目的探讨MRI多征象分析诊断半月板桶柄状撕裂（BHT）的价值。方法回顾性分析84个经关节镜证实为半月板损伤的膝关节的MR图像,其中42个膝关节为半月板BHT,另42个膝关节为非BHT。观察以下8种征象：双后交叉韧带（PCL）征、半月板翻转征、空领结征、领结残破征、后角残破征、厚饼征、碎块内移征及外周残半月板征,分别计算每种征象诊断半月板BHT的敏感度、特异度、阳性预测值、阴性预测值和准确率。结果双PCL征、半月板翻转征、厚饼征、碎块内移征及外周残半月板征具有相对高的特异度,但除碎块内移征及外周残半月板征的敏感度相对高外,其余6种MRI征象的敏感度均较小。结论半月板BHT可有多种MRI表现,碎块内移征与外周残半月板征最具诊断价值,而双PCL征、半月板翻转征及厚饼征特异度较高,这些征象的出现强烈提示半月板BHT。

Multiple MRI signs in diagnosis of bucket-handle tears of the knee menisci

Objective To assess the diagnostic value of multiple MRI signs in diagnosis of bucket-handle tears (BHT) of the knee menisci. Methods MRI images of 84 knee joints with menisci injury were retrospectively analyzed. There were 42 knees with BHT of menisci and 42 knees without BHT of menisci according to arthroscopy. Double posterior cruciate ligament sign, flipped meniscus sign, absent bow tie sign, bow tie broken sign, posterior angle broken sign, thick pastry sign, internal displaced fragment sign and abnormal circumferential meniscus sign were observed. The sensitivity, specificity, positive and negative predictive values and accuracy for diagnosing BHT of menisci were calculated for the presence of each individual sign. Results Among these eight signs, double posterior cruciate ligament sign, flipped meniscus sign, thick pastry sign, internal displaced fragment sign and abnormal circumferential meniscus sign had relative high specificities. Most of the signs except internal displaced fragment sign and abnormal circumferential meniscus sign, however, had relative low sensitivities. Conclusion BHT of menisci have many signs on MRI. The internal displaced fragment sign and abnormal circumferential meniscus sign are the two most valuable signs in diagnosing BHT of the knee menisci. The presence of double posterior cruciate ligament sign, flipped meniscus sign and thick pastry sign are the best predictors of the BHT.