板股韧带的MRI研究及临床意义

目的　明确板股韧带正常MRI表现 ,建立由它所致假撕裂与外侧半月板后角真撕裂的鉴别方法。资料与方法　采用 6 0侧正常膝进行矢状和冠状位MR扫描 ,观察板股韧带的MRI表现。结果　板股韧带显示率为88.3% (5 3侧 ) ,其中板股前韧带为 2 6 .7% (16侧 )、板股后韧带为 86 .7% (5 2侧 )和两条韧带同时存在为 2 3.3% (14侧 )。板股韧带在矢状像上表现为位于后交叉韧带前或后方的类圆形或短棒状低信号结构 ,而在冠状像上表现为自外侧半月板后角至股骨内侧髁外侧面的条带样低信号结构。在矢状像上 ,5 2 .8% (2 8/5 3)板股韧带与外侧半月板后角之间显示出一线样高信号 ,被称为假撕裂 ,易与外侧半月板后角撕裂混淆。但假撕裂仅有两种走行方向即后下斜行 (2 1/2 8)或垂直方向 (7/2 8)。结论　根据假撕裂位置、方向以及冠状像和连续矢状面的观察 ,可正确区分外侧半月板后角真假撕裂

MRI Study of the Meniscofemoral Ligament and Its Clinical Significance

Objective To determine the MR appearance of the meniscofemoral ligament (MFL), and to establish a method to differentiate pseudotears of the posterior horn of the lateral meniscus caused by the MFL from true tear of that.Materials and Methods MR examinations of 60 normal knees were performed in the sagittal and coronal plane, and then the MR appearance of the MFL was carefully observed.Results The MFL was present in 88.3%(53 cases), which included the anterior MFL (16 cases,26.7%), the posterior MFL (52 cases, 86.7%) and the two ligaments coexisted (14 cases, 23.3%). In sagittal plane, the MFL was identified as a circle-like or short stick-like area of low signal intensity anterior or posterior to the posterior cruciate ligament. Nevertheless, a belt-shaped area of low signal intensity from the posterior horn of the lateral meniscus to lateral facet of the medial femoral condyle was identified in the coronal plane. A linear area of high signal intensity between the MFL and the lateral meniscus was seen in 52.8%(28/53 cases)in sagittal plane, we briefly called it pseudotears that may be confused with tear of the posterior horn of the lateral meniscus. But all pseudotears we observed had either in posteroinferiorly oblique direction (21/28 cases) or in vertical direction (7/28 cases).Conclusion Based on the location and direction of pseudotears and observation in the continous sagittal plane and the coronal plane, we can easily differentiate pseudotears from the true tear of posterior horn of the lateral meniscus.