Naganawa S, Yamakawa K, Fukatsu H, Ishigaki T, Nakashima T, Sugimoto H, Aoki I, Miyazaki M, Takai H
Department of Radiology, Nagoya University School of Medicine, Japan.
Eur Radiol. 1996;6(3):369-74. doi: 10.1007/BF00180615.
The purpose of this study was to assess the value of a long echo-train-length 3D fast spin-echo (3D-FSE) sequence in visualizing the inner ear structures. Ten normal ears and 50 patient ears were imaged on a 1.5T MR unit using a head coil. Axial high-resolution T2-weighted images of the inner ear and the internal auditory canal (IAC) were obtained in 15 min. In normal ears the reliability of the visualization for the inner ear structures was evaluated on original images and the targeted maximum intensity projection (MIP) images of the labyrinth. In ten normal ears, 3D surface display (3D) images were also created and compared with MIP images. On the original images the cochlear aqueduct, the vessels in the vicinity of the IAC, and more than three branches of the cranial nerves were visualized in the IAC in all the ears. The visibility of the endolympathic duct was 80%. On the MIP images the visibility of the three semicircular canals, anterior and posterior ampulla, and of more than two turns of the cochlea was 100%. The MIP images and 3D images were almost comparable. The visibility of the endolymphatic duct was 80% in normal ears and 0% in the affected ears of the patients with Meniere's disease (p < 0.01). In one patient ear a small intracanalicular tumor was depicted clearly. In conclusion, the long echo train length T2-weighted 3D-FSE sequence enables the detailed visualization of the tiny structures of the inner ear and the IAC within a clinically acceptable scan time. Furthermore, obtaining a high contrast between the soft/bony tissue and the cerebrospinal/endolymph/ perilymph fluid would be of significant value in the diagnosis of the pathologic conditions around the labyrinth and the IAC.
本研究的目的是评估长回波链长度三维快速自旋回波（3D-FSE）序列在显示内耳结构方面的价值。使用头部线圈在1.5T磁共振成像设备上对10只正常耳和50只患者耳进行成像。在15分钟内获得内耳和内耳道（IAC）的轴向高分辨率T2加权图像。在正常耳中，在内耳原始图像和靶向最大强度投影（MIP）图像上评估内耳结构显示的可靠性。在10只正常耳中，还创建了三维表面显示（3D）图像并与MIP图像进行比较。在原始图像上，所有耳的内耳道内均可显示蜗水管、IAC附近的血管以及三条以上的颅神经分支。内淋巴管的显示率为80%。在MIP图像上，三个半规管、前后壶腹以及耳蜗两圈以上的显示率为100%。MIP图像和3D图像几乎相当。内淋巴管在正常耳中的显示率为80%，在梅尼埃病患者的患耳中为0%（p<0.01）。在一只患者耳中清晰显示了一个小的管内肿瘤。总之，长回波链长度T2加权3D-FSE序列能够在临床可接受的扫描时间内对内耳和IAC的微小结构进行详细显示。此外，在软组织/骨组织与脑脊液/内淋巴/外淋巴液之间获得高对比度对于迷路和IAC周围病理状况的诊断具有重要价值。
