【摘要】 目的　建立正常成人CT轴位扫描眼外肌的直径标准、眼外肌群直径总和与颧骨间距比值及眼球的正常位置。方法　从10 0例正常成人共 2 0 0个眼球结构中 ,在轴位CT上分别测量眼外肌的直径、颧骨间距、从颧骨间平面到眼球后缘的距离、球后至眶尖的距离及视神经鞘的宽度 ,同时分析眼外肌群直径总和与颧骨间距的比值。结果　眼外肌正常直径范围 :内直肌 2 .7～ 5 .2mm ,平均 4.0mm。外直肌 1.8～ 4.9mm ,平均 3.4mm。下直肌 5 .4～ 9.1mm ,平均 7.8mm。上直肌群 6 .7～ 10 .2mm ,平均 8.5mm。视神经鞘为 3.1～ 5 .6mm ,平均 4.4mm。眼球后缘正常位置为颧骨间线后 8.7mm(范围 5 .4～ 11.9mm) ,球后至眶尖 33mm(范围 2 4～ 42mm) ,眼外肌总和与眶骨间距比值为 0 .2 3(范围 0 .19～ 0 .2 6 )。结论　CT测量眼眶结构简便易行 ,并检出测量的参考层面标准更多还原

【Abstract】 Objective To establish the normal criteria for the diameter of each extraocular muscle,to calculate the ratio of the diameter of all extraocular muscles to the length of the interzygomatic line and to determine the normal position of the globe of adults as revealed by axial CT.Methods Diameters of extraocular muscles,the length of interzygomatic line,distance from the interzygomatic line to the posterior margin of the globe,width of the optic nerve-sheath and distance from the posterior margin of the globe to the tip of orbita were measured for 200 normal orbits of 100 adults on axial CT images,and calculated the ratio of the sum of the diameters of all extraocular muscles to the length of interzygomatic line.Results Normal range for the diameters of extraocular muscles were medial rectus 2.7～5.2 mm(mean 4.0 mm),lateral rectus 1.8～4.9 mm(mean 3.4 mm),inferior rectus 5.4～9.1 mm(mean 7.8 mm)and superior groups 6.7～10.2 mm(mean 8.5 mm).The width of the optic nerve-sheath was 3.1～5.6 mm(mean 4.4 mm),the normal position of the postenior margin of the globe was 8.7 mm behind the interzygomatic line(range 5.4～11.9 mm),the distance of posterior margin of the globe to the tip of orbita was 33 mm(range 24～42 mm),the ratio of the sum of the diameters of all extraocular muscles to the length of interzygomatic line was 0.23(range 0.19～0.26).Conclusion The normal criteria of orbital structures is important,especially in finding early changes of globe,extracular muscles and optic nerve.更多还原