急性前交叉韧带损伤MRI多征象与关节镜对照研究

Comparative study on the MRI multi-imaging with arthroscopy in acute anterior cruciate ligament injury

目的:探讨急性前交叉韧带(ACL)损伤的MRI多种征象的诊断价值。方法:选择ACL损伤病人23例,在不告知关节镜诊断结果前提下,由2名MRI诊断医师共同对MRI多种征象进行分析,统计各种征象诊断的敏感度、特异度以及阳性预测值,明确多种MRI征象出现率。结果:采用MRI检查在ACL连续中断、ACL走行异常、ACL消失、ACL吊桥征、胫骨前移、外侧半月板后角后移、"对吻性"骨挫伤及Notch征、空髁间窝征多种征象上具有较大的诊断价值(P<0.05～P<0.01)。ACL损伤的MRI直接征象中ACL消失敏感性最低(13.04%),而ACL局限或弥漫性信号增高或增粗特异性相对较低;其中韧带走行异常诊断价值最大,其诊断敏感度、特异度及阳性预测值分别为73.91%、100.00%及100.00%。ACL损伤的MRI间接征象中胫骨前移位、外侧半月板后角后移、"对吻性"骨挫伤及Notch征、空髁间窝征4种间接征象具有较高的特异度,但敏感度均较低,其中"对吻性"骨挫伤及Notch征诊断价值最大。结论:MRI直接征象是急性ACL损伤诊断的主要依据,综合分析特异性较强的间接征象,可减少MRI假阴性诊断率,同时对诊断ACL完全撕裂较部分撕裂的可靠性大,尤其是直接征象表现不典型的急性ACL损伤者。

Objective:To explore the diagnostic value of MRI multi-imaging in acute anterior cruciate ligament(ACL) injury. Methods:The multiple signs of MRI of ACL injury in 23 patients were analyzed by two MRI diagnostic physicians without knowledge of arthroscopic diagnosis. The sensitivity,specificity and positive predictive value of magnetic resonance imaging(MRI) multi-imaging were analyzed,and the likelihood ratio of MRI multi-imaging was identified. Results:The values of MRI in the diagnosis of multi-imaging, which included ACL continuous interruption,abnormality of ligament shape,disappearance of ACL,ACL suspension bridge sign,anterior tibia,posterior angle of lateral meniscus,contusion of "proboscis" bone,Notch sign and empty intercondylar fossa sign,were great(P < 0. 05 to P < 0. 01). In MRI direct signs of ACL injury,the sensitivity of ACL disappearance was the lowest(13. 04%),while the specificity of ACL limited or diffuse signal enhancement or thickening was relatively low. The diagnostic value of abnormality of ligament shape was the greatest,and the diagnostic sensitivity,specificity and positive predictive value were 73. 91%,100. 00% and 100. 00%, respectively. Among the MRI indirect signs of ACL injury,the specificities and sensitivities of anterior displacement of tibia,posterior angle of lateral meniscus,contusion of "kiss" bone,Notch sign and empty intercondylar fossa sign were higher and lower,respectively. The diagnostic values of contusion of "kiss" bone and Notch sign were the greatest. Conclusions:The MRI direct sign is the main basis in the diagnosis of acute ACL injury. The comprehensive analysis of high specificity indirect signs can reduce the false negative diagnostic rate of MRI,and it is more reliable to diagnose complete ACL tear compared with partial tear,especially for acute ACL injury with atypical direct signs.