【摘要】 目的用MRI 研究正常人原在位4条直肌在眼眶中的静态位置及舒缩运动时的变化。方法应用眼球动态MRI 技术,获取20名正常人在原在位及眼球水平和垂直方向转动时的冠状位磁共振图像,应用计算机图像处理软件测量原在位时4条直肌横截面中心相对眼眶中心的坐标值及4条直肌收缩和松弛时横截面积的变化。在MRI 冠状位图像眼球-视神经连接平面上,规定直肌位于眼眶中心内侧及上方为正值。结果(1)原在位时, 相对于眼眶中心的坐标值分别为内直肌12.47mm,-2.24mm;外直肌-14.37mm,-2.87mm;上直肌1.87mm, 11.73mm;下直肌4.83mm,-11.31mm;(2)原在位及4条直肌收缩和松弛时,在MRI 图像上直肌最大横截面积所在层面位于眼球一视神经连接平面后约6mm 处;(3)直肌收缩和松弛时,MRI 图像上其横截面积变化幅度由大到小依次为上直肌、下直肌、内直肌、外直肌。结论正常人原在位MRI 图像4条直肌横截面中心在眼眶内坐标值及4条直肌收缩和松弛时横截面积变化的正常比值的建立,为眼外肌病的MRI 诊断及手术治疗提供了参考依据。更多还原

【Abstract】 Objective To study the rectus muscle coordination in primary position on the orbital MRI and the rectus muscle cross-section changement when they contract and relax on the ocular dynamic MRI in normal cases. Methods Images of ocular dynamic MRI scan were obtained in primary、left、right、up、down gaze in 20 normal cases.The coordination and the rectus cross-section changement were measured with computer software on the images of the coronal MRI.Results(1)In the primary position,on the plane of eye-optic nerve cross,the coordination of the medial rectus,lateral rectus,superior rectus and inferior rectus muscle relative to the orbital center are(12.47mm, -2.24mm)、(-14.37mm,-2.87mm)、(1.87mm,11.73mm)、(4.83mm,-11.31mm);(2)In the primary、left、right、 up、down gaze,the largest cross-section of the rectus muscles is on the plane of 6mm posterior to the plane of eye- optic nerve cross on the images of coronal MRI scan;(3)When the rectus contract and relax,the most obvious changement of cross-section is the superior rectus muscle,next the inferior rectus,the medial rectus and the lateral rectus muscle respectively.Conclusions We established the rectus muscle coordination of the normal Chinese on the image of coronal orbit MRI and the rate of the cross-section changement when the rectus contract and relax in this study,which may help us to diagnose and treat the strabismus.更多还原