MRI评价膝关节半月板的桶柄状撕裂

目的 明确5种MRI征象对膝关节半月板桶柄状撕裂的诊断价值。方法 回顾135例患者139个经关节镜证实的膝关节MR图像，其中19个存在半月板桶柄状撕裂。在均不告知关节镜结果的条件下，由2名有经验的放射医生对所有图像进行独立读片，差异协商解决。每个膝关节均记录如下5种MRI征象：双后交叉韧带征(双PCL征)、半月板翻转征、空领结征、碎块内移征和外周残半月板征。分别计算每种征象诊断半月板桶柄状撕裂的敏感度、特异度、阳性预测值、阴性预测值和准确度。结果 5种征象的诊断敏感度分布于52．6％和89．5％之间，特异度分布于83．3％和98．3％之间，阳性预测值分布于42．9％和88．2％之间，阴性预测值分布：于92．7％和98．3％之间，准确度分布于82．7％和96．4％之间。“碎块内移征”和“外周残半月板征”的诊断敏感度最高，“双PCL征”的诊断特异度和阳性预测值最高，而“碎块内移征”具有最高的阴性预测值和诊断准确度。结论 半月板桶柄状撕裂在MRI上可以有多种表现，各种征象对诊断的能力有所不同。

MRI evaluation of the bucket handle tears of menisci of the knee

Objective To determine the val ue of five MR imaging signs in diagnosing the bucket handle tears (BHT) of menisci of the knee. Methods MR imaging of 139 knees with subsequent arthroscope exams were retrospectively evaluated. Based on the results of arthroscopy, 19 knees had BHT of menisci. Two radiologists evaluated each MR exam independently, with discrepancies resolved by consensus. Each MR exam was analyzed for five signs: a double posterior cruciate ligament sign, a flipped meniscus sign, an absent bow tie sign, an internal displaced fragment sign, and an abnormal circumferential meniscus sign. Sensitivity, specificity, positive and negative predictive values, and accuracy for diagnosing BHT of menisci were calculated for the presence of each individual sign. Results The sensitivities of these five signs ranged between 52.6% and 89.5%, and specificities ranged between 83.3% and 98.3%, respectively. Positive and negative predictive values ranged between 42.9% and 88.2%, and between 92 7% and 98.3%, respectively. The accuracy of these five signs ranged between 82.7% and 96 4%. Conclusion BHT of menisci may have many signs on MR imaging. The diagnostic sensitivities of the internal displaced fragment sign and the abnormal circumferential meniscus sign are the highest. The double posterior cruciate ligament sign has the highest specificity and positive predictive value, while the internal displaced fragment sign has the highest negative predictive value and accuracy.