摘要
目的探讨膝板股韧带（MFL）附着区半月板真、假性撕裂的MRI表现及鉴别诊断要点。方法回顾性分析经关节镜检查证实为MFL附着区外侧半月板后角（PHLM）撕裂患者32例作为真性撕裂组，32例患膝均伴发前交叉韧带（ACL）损伤；搜集同期行关节镜检查证实ACL损伤且PHLM完整的30例患者作为ACL损伤对照组；招募健康志愿者20名作为无症状对照组。所有受试者均行膝关节MRI检查。在MRI矢状面图像上测量纵行线状高信号显示的层数，在横断面图像上测量线状高信号的长度。采用单因素方差分析比较3组患者膝关节线状高信号层数和长度的差异，采用ROC曲线分析纵行线状高信号显示的层数、线状高信号的长度鉴别诊断真、假性撕裂的效能，采用x2检验比较各组间MRI征象发生率差异。结果无症状对照组20例中的16例、ACL损伤对照组30例中的25例正常板股韧带附着区出现纵行线状高信号（82．0％，41／50），为假性撕裂。真性撕裂组、ACL损伤对照组、无症状对照组的矢状面连续显示层数分别为（5．8±1．2）、（2．6±1．1）、（2．7±1．4）层，横断面长度分别为（16．4±4．9）、（8．1±3．2）、（6．0±3．1）mm，3组间差异均有统计学意义（F值分别为60．9、17．0，P均〈0．01）。采用矢状面连续显示层数鉴别真、假性撕裂的ROC曲线下面积为0．96，以≥5层为“连续线征”阳性的标准，其诊断的敏感度、特异度和准确度分别为90．6％（29／32）、90．2％（37／41）及90．4％（66／73）。采用横断面长度鉴别真、假性撕裂的ROC曲线下面积为0．92，以长度t〉10mm为“拉链征”阳性的标准，其诊断的敏感度、特异度和准确度分别为84．4％（27／32）、90．2％（37／41）及87．7％（64／73）。真性撕裂组、ACL损伤对照组、无症状对照组3组冠状面MFL起始部信号增高的发生率分别为71．9％（23／32）、60．0％（15／25）和10／16，差异无统计学意义（X2=0．98，P=0．61）。结论“连续线征”、“拉链征”是MFL附着区半月板撕裂的特征性MRI表现，有助于与假性撕裂鉴别。
Objective To analyze MRI features of real tears and pseudotears of posterior horn of the lateral meniscus （PHLM） at the insertion site of meniscofemoral ligament（MFL）, and to discuss main points of differential diagnosis. Methods MR images of 32 patients with PHLM tears and 30 patients with anterior cruciate ligament tears but without PHLM tears confirmed by arthroscopy were analyzed retrospectively. Another 20 asymptomatic volunteers as controls underwent MR examination and analyzed. The number of consecutive slices displaying longitudinal increased signal in sagittal images and the length in axial images were evaluated. The one- way analysis of variance, X2 test and ROC curve were used to analyze diagnostic value of different MRI findings. Results Longitudinal line with abnormal increased signal （pseudotear） was found in 82.0% （41/50） normal insertion site of MFLs. The typical MRI finding of real tears was peripheral longitudinal linear high signal in PHLM which reached the margin of articular surface. In sagittal images, longitudinal linear high signal was shown in （5.8± 1.2） slices in knees of real tears, which was more than （2.6±1.1） slices and （2.7±1.4） slices in pseudo-tear groups （F=60.9, P〈0.01）. The area under ROC curve was 0.96 for differentiating real tear from pseudo-tear using the number of consecutive slices displaying longitudinal increased signal in sagittal images. With a threshold of five or more consecutive images with abnormal longitudinal increased signal as the positive standard of continuousline sign, the overall sensitivity, specificity and accuracy for diagnosing real tear were 90.6% （29/32）, 90.2% （37/41） and 90.4% （66/73）, respectively. The axial images showed that the length of increased signal line in the outer of PHLM was （16.4±4.9） mm in patients with real tears, which was longer than pseudo-tear groups with length of （8.1±3.2） mm and （6.0±3.1） mm （F=17.0, P〈0.01）. The area under ROC curve was 0.92 for differentiating real tear from pseudo-tear using the length in axial images. The zip sign was defined when its length was not less than 10 ram. The sensitivity, specificity and accuracy of the zip sign was 84.4% （27/32）, 90.2% （37/41） and 87.7% （64/73） respectively. In coronal images, high signal of MFL attachment insertion was shown in 71.9% （23/32）, 60.0% （15/25） and 10/16 cases, there was no significant difference （X2=0.98, P=0.61）. Conclusion The continuous-line sign arid zip sign are characteristic findings of PHLM tears at the insertion site of MFL attachment, which are valuable for differential diagnosis with pseudotears at the insertion site of MFL.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2016年第4期269-273,共5页
Chinese Journal of Radiology
关键词
半月板
胫骨
韧带
创伤和损伤
磁共振成像
Menisci, tibial
Ligaments
Wounds and injuries
Magnetic resonance imaging
