MRI上不同角度斜断面对踝关节外侧韧带显示效果的研究

MR imaging study of the lateral ankle ligaments through anatomic analysis

目的:寻找踝关节外侧韧带于自然体位下MRI显示最佳的斜断面,为临床更好地评价外侧韧带提供依据。方法:解剖15例自然体位的正常踝关节标本,分离出外侧韧带,测出它们的长轴走行角度,据此制定MRI扫描方案;35例自愿者行踝关节MRI扫描,扫描方位包括常规横断面,冠状面及不同角度斜断面,比较不同扫描方位上各韧带的显示效果。结果:ATFL的显示以20°斜断面效果最佳,其次是横断面和30°斜断面,两者显示效果相当,45°斜断面次之。CFL的显示以-15°斜断面效果最佳,其次是-25°斜断面,横断面和-35°斜断面次之,但两者显示效果相当。CFL的整体显示率较ATFL低。冠状面对ATFL和CFL的显示不满意,但可满意显示PTFL。结论:MRI评价踝关节外侧韧带时,选择适当的扫描方位可以达到最佳的显示效果。

Objective： To look for optimal oblique planes according to the courses of the lateral ankle ligaments with the foot positioned naturally for better evaluating them clinically.Methods： Fifteen eadaverie ankles were dissected and the lateral ankle ligaments were exposed. The orientations of each ligament were determined. We performed MR scans in thirty-five volunteers with routine coronal, axial and various oblique planes which were determined as mentioned above. Then comparisons were made among different scans as to their display effects.Results：Regarding ATFL display, the 20°oblique plane provided the best view, followed by routine axial and 30°oblique planes which shared the statistically same display effect, tben 45°oblique plane. Among various scans the - 15°oblique plane offered the optimal images of CFL, followed by - 25°oblique plane, then the routine axial and - 35°oblique planes with the statistically same result. The overall intact display rate of CFL was lower than that of ATFL. Coronal plane was not satisfying in imaging ATFL and CFL, but was suitable for visualizing PTFL. Conclusion： When evaluating the lateral ankle ligaments with MRI, choice of appropriate scan plane will obtain the best images.