正常人内耳结构的MR测量

MRI measurement for inner ear structrues of nomal people

目的：利用快速三维梯度回波序列采集内耳所在区域内水的信号送Adw4．2工作站进行图像三维重建，建立内耳各主要结构的MRI测量正常值。方法：将60例健康志愿者按年龄分为学龄前组（≤7）、学龄组（8～14岁）、青春期组（15～20岁）、青年组（21～45岁）、中老年组（≥46），共120只内耳分别行3D-Fiesta扫描。原始数据于工作站后处理，行最大强度投影（MIP）重建，多角度旋转并测量内耳各主要结构的径线，剪切去除周围组织测量内耳液体体积。各观察指标就侧别、性别和年龄组间进行比较。结果：①3D-Fiesta序列重建图像可清晰显示正常膜迷路结构；②内耳液体体积、三个半规管高度、管径，耳蜗底周管径、直径，前庭长、短径均无年龄、性别、侧别组间的差异。分别为：上半规管管径1．04±0．21mm，高度6．24±0．58mm；水平半规管管径1．08±0．25mm，高度4．56±0．47mm；后半规管管径1．47±0．35mm，高度6．08±0．62mm；前庭长短径分别为：4．78±0．30mm，3．17±0．25mm；耳蜗底周直径7．12±0．39mm，管径1．87±0．16mm；内耳膜迷路液体体积0．230±0．028cm^3。结论：制定了国人内耳各主要结构MRI测量正常值。正常人内耳各主要结构的大小无性别、年龄、侧别之间的差异。

Objective： To reconstruct the image of inner ear by using 3D-Fiesta MR imaging technique, and to establish MRI measurement criteria of inner ear structures. Methods： The temporal bones of 60 volunteers （120 ears） were imaged using IAC （internal auditory canal） 3D-Fiesta MR imaging sequence, the volunteers were divided into five groups according to age. All the original image data were transferred to a post-processing ADW4.2 workstation, all the structures of inner ear were reconstructed, rotated in various directions and measured by using maximum intensity projection （MIP）, surrounding tissues were cut to obtain the volume of inner ear membrous labyrinth. Results： ① All the structures of inner ear could be visualized dearly in MIP imagings; ② No age-, sex-, or side-related differences in the inner ear structures were found. The height of superior, horizonal and posterior semicircular canal were 6.24±0.58mm, 4.53±0.47mm, 6.08±0.62mm, respectively. The diameter of superior, horizonal and posterior semicircular canal were 1.04±0.21mm, 1.08±0.25mm, 1.47±0.35mm, respectively. The dimensions of irregular cylinder-vestibule were 4.78±0.30mm, 3.17±0.16mm, respectively. The external diameter and diameter of cochlea basal turn were 7.12±0.39mm, 1.87±0.16mm, respectively. The membrous labyrinth was 0.230±0.028cm^3. Conclusion： The MRI measurement criteria of inner ear structures is established. There were no age-, sex-, or side-related differences in the inner ear structures in normal subjects.