正常人内耳前庭、半规管及耳蜗的MRI测量

MRI measurement for inner ear structures

目的 利用高级快速自旋回波 (FASE)重T2 WI三维重建技术重建正常内耳膜迷路 ,建立内耳系统各主要结构的MRI测量正常值。方法 将 5 3例健康志愿者按年龄分为婴幼儿组、少年组、青年组、中年组和老年组 ,共 10 6只内耳分别行三维 ( 3D)FASE重T2 WI横断扫描。原始图像行最大强度投影 (MIP)重建 ,多角度旋转并测量内耳各主要结构的径线 ( 3个半规管高度和管径 ,耳蜗蜗高、底周直径和管径 ,前庭垂直径 ) ;行透视容积成像 (PVR)重建测量内耳液体容积。各观察指标就侧别、性别和年龄组间进行比较。结果 ( 1) 3DFASE重T2 WI可清晰显示正常膜迷路结构和内听道内的神经 ;( 2 )内耳液体容积无年龄组间、侧别间差异 ,但男性 ( 0 2 42± 0 0 2 3 6)mm3与女性 ( 0 2 2 6±0 0 2 1)mm3间差异有非常显著性意义 (P <0 0 0 1)。 3个半规管高度、前庭垂直径无年龄组间、侧别间差异 ,但上半规管高度男性 ( 5 5 11± 0 62 6)mm与女性 ( 5 167± 0 3 5 7)mm间差异有非常显著性意义(P <0 0 0 1) ;水平半规管高度男性 ( 3 763± 0 495 )mm与女性 ( 3 44 6± 0 40 5 )mm间差异有非常显著性意义 (P <0 0 0 1) ;后半规管高度男性 ( 5 2 2 7± 0 5 47)mm与女性 ( 4 786± 0 5 0 0 )mm间差异有非常显著性意义 (

Objective To reconstruct the image of inner ear by using 3D-FASE heavily T 2WI, and to establish MRI measurement criterion of inner ear structures. Methods One hundred and six inner ears of 53 healthy volunteers underwent MRI heavily T2-weighted axial scanning by using 3D fast advanced spin echo sequence. All the original images were transferred to an online workstation. Analyze AVW software was used for image post-processing. All the structures of inner ear were reconstructed, rotated from various angles and measured by using maximum intensity projection (MIP). Results (1) All the structures of inner ear and internal auditory cannel (IAC) could be visualized clearly by using 3D-FASE heavily T 2WI. (2) Using analysis of variance, there was no age, side or race-related difference in inner ear volume, but it was bigger in male than in female [(0.242±0.023 6) mm 3(male) versus (0.226±0.021) mm 3(female)]. There was no age, side-related differences in three semicircular canal height and vestibule vertical diameter, but, again, they were bigger in male than in female. The height of upper, lateral and posterior semicircular canal were (5.511±0.626) mm(male) versus (5.167±0.357) mm(female); (3.763±0.495) mm(male) versus (3.446±0.405) mm(female); (5.227±0.547) mm(male) versus (4.786±0.500) mm(female). There was no age, sex or side-related differences in three semicircular canal diameter and cochlea. The diameter of upper, lateral and posterior semicircular canal were (1.06±0.119) mm, (1.14±0.181) mm,and (1.22±0.196) mm;the external diameter of cochlea basal turn was (6.520±0.475) mm,the diameter of cochlea basal turn was (1.413±0.144) mm, and cochlea height was (4.100±0.405) mm. Conclusion (1) For the first time, the MRI measurement criterion of inner ear structures is established. (2) Vestibule and three semicircular canal of inner ear are bigger in male than in female.