眼眶内侧壁生理性凹陷的CT分析

Analysis of physiological pit in medial orbital wall with CT

目的:探讨眼眶内侧壁生理性凹陷在CT中的形态表现并测量相关参数,以加强对内侧壁生理性凹陷的认识。方法:21例单侧内侧壁生理性凹陷的病例根据其在CT横断位上的形态将其分型,并进行相关参数测量。结果:根据凹陷在CT横断位上的形态表现将其分为:弧形凹陷15例、成角凹陷4例、不规则凹陷2例。相关参数:(1)凹陷深度:最小2.1 mm,最大6.4 mm,平均深度(4.0±1.4)mm;(2)凹陷前后径长度:最小5.1 mm,最大19.7 mm,平均长度(13.3±3.7)mm;(3)凹陷顶端所在区间:横断位以筛骨纸板中1/3多见、后1/3次之、前1/3最少,冠状位以纸板上区多见、跨上下区次之、下区最少。结论:正常人群约有2.6%眼眶内侧壁存在生理性凹陷,对其形态及相关参数的了解,有助于加强对内侧壁生理性凹陷的认识,提高与骨折凹陷的鉴别能力。

Objective： To analyze CT findings of physiological pit in medial orbital wall. Methods： Twenty-one cases with physiological pit in medial orbital wall were included and classified according to the features of axial CT images. Related pa-rameters were measured. Results： According to axial CT image features, the cases were divided into 3 categories： arc sunken pit（15 cases）, angle sunken pit（4 cases） and irregular sunken pit（2 cases）. Related parameters：（1）Depth of the sunken pit：minimum depth 2.1 mm, maximum depth 6.4 mm, average depth（4.0 ±1.4） mm.（2）Length of the sunken pit： minimum length5.1 mm, maximum length 19.7 mm, average length（13.3±3.7） mm.（3）Position of the apex of a sunken pit, on axial CT image：middle 1/3 of lamina was the most common, back 1/3 was the second, front 1/3 was the least; on coronal CT image： the up-per half of lamina orbital was the most common, the lower half was the least. Conclusion： 2.6% of the people have physiological pit in the medial orbital wall. The understanding of this phenomenon can improve the identification ability of physio-logical sunken pit and fracture.