薄层CT容积重建技术对乙状窦后入路切入点与标志点的形态学测量及其意义

目的:利用影像学方法测量乙状窦后入路切入点与特定标志点的距离和特定标志面夹角，为听神经瘤手术乙状窦后入路提供指导。方法：对100名志愿者的乙状窦、颈静脉孔和听耳道进行CT扫描，利用三维重建技术，以过手术入路平行于眼耳平面的平面和鼻中隔所在平面作为测量平面，分别测量横窦乙状窦转折处（A）、颈静脉孔上缘（B）、内听道下缘（C）三者之间的距离(记为AB、AC和BC)以及颈静脉孔到AC边的最短距离。测量AC和AB与矢状轴所成夹角（α和β）。结果：AC的长度为（45.20±3.97）　mm，AB的长度为（44.27±4.68） mm，BC的长度为（6.18 ±2.02）　mm，颈静脉孔到AC的最短距离为（5.27±2.03） mm，角α测量值为（39.07±4.86）°；角β测量值为（45.99±5.62）°。结论：得到乙状窦后入路中手术切入点与标志点的距离和夹角及手术入路距颈静脉孔的安全距离。

Morphologic measurement of entry points and landmarks of retrosigmoid approach using volume rendering with thin-section computed tomography and its significance

Objective To research the jugular foramen,internal auditory pore(IAP)and the turning point between its components by imageological methods and to provide theoretical basis for retrosigmoid approach in the operation of acoustic neurinoma.Methods The skulls of 100 volunteers were scanned to get the final result with thin-section computed tomographic image.High-resolution spiral CT multiplane reformation was used to reform images that were parallel to the Frankfort horizontal plane to measure the distance between the turning point of retrosigmoid(A),the edge of jugular foramen(B)and the lower edge of the internal auditory canal(C)(denoted AC,AB,BC)and the shortest distance from the jugular foramen to AC.The angles between AC,AB and sagittal axis(α,β)were measured.Results The distance of AC was(44.94±3.84)mm,the distance of AB was(43.68±4.56)mm.The distance of BC was(6.15±2.04)mm,and the shortest distance between jugular foramen and AC was(5.21±0.23)mm.The angleαwas measured as(39.50±4.74)°,and the angleβwas measured as(46.35±5.51)°.Conclusion The research measure the distance and angle between entry points and landmarks of retrosigmoid approach and the safe distance.