耳部正常结构多层螺旋CT容积重建技术(VR)评估

目的探讨容积重建技术(VR)对耳正常结构的应用价值,并与其他几种后处理技术做比较.资料与方法采用多层螺旋CT(MSCT)机,对20例(40耳)健康志愿者行准直0.5 mm,螺距0.5～0.875 D的螺旋超高分辨率扫描,在此基础上进行VR和MPR、SSD、VE、Ray Sum、MIP/MinIP重建,比较各种重建技术对耳部听小骨及内耳等结构的显示能力.结果 VR对耳部各骨性和膜性精细结构和神经组织均可清晰显示,从显示清晰度来看,依次为VR、MPR、SSD、MIP/MinIP.Ray Sum和VE分别仅对内耳和听小骨显示佳.结论采用MSCT机薄层耳部扫描,VR能从平面和立体直观地显示耳部听小骨及内耳各细微结构,且可全面清晰立体观察膜迷路、前庭及与内听道内面、听神经的关系.

The Evaluation of the Normal Ear Structures Using MSCT Volume Rendering

Objective To discuss the value of MSCT VR in showing the normal ear anatomic structures, and compare VR with other reconstruction methods.Materials and Methods 20 volunteers(40 ears) were underwent with MSCT spiral ultra high resolution scan using collimation 0.5, pitch 0.5-0.875. The various reconstructions including VR and MPR, SSD, VE, Ray Sum, MIP/MinIP were made for the comparison of their ability in showing the normal structures of the ear in each case.Results VR was the most optimal method to show every fine structure including bone, membrane and nerve clearly, successionally in descending order VR, MPR, SSD, MIP/MinIP according to clarity. Ray Sum was only fit to inner ear, meanwhile VE was suitable to showing the auditory ossicle. Conclusion MSCT ultra-thin section scan (0.5mm) using volume rendering can display the fine structures of ears from the view of plane and three-dimension, as well as the relationship between membrane labyrinth, vestibule and facial/auditory nerve in the inner auditory canal entirely.