舌下神经断层解剖与MRI

目的：研究舌下神经在不同断面上的位置、毗邻、走行及识别标志，为舌下神经病变的影像学诊断和外科手术提供形态学依据。方法：取用国人成年尸体头部标本69例，以冷冻切片法切制成连续横断层标本36例、矢状断层标本18例和冠状断层标本15例；招募成年志愿者10名，利用3．0TMRI扫描仪，以3D—CISS序列扫描，获取横、矢状、冠状断层图像；在上述断层标本对照下，于MR图像上观察舌下神经在断面上的形态、位置、毗邻和识别标志等。结果：在横断面上，可见枕骨基底部两侧呈倒“八”字形的舌下神经管，管内走行着舌下神经；在矢状断面上，舌下神经管呈椭圆形，位于小脑前下方，岩下窦与寰枕关节之间；在经舌下神经管外口的冠状断面上，舌下神经管外口位于寰枕关节外上方、颈内静脉内侧，其间容纳舌下神经；在经舌下神经管内口的冠状断面上，呈“鸟喙”状的舌下神经管内口居枕骨侧部内，其内侧为延髓，外侧为颈内静脉，上方为颈静脉孔，下方为寰枕关节。结论：在横、矢状和冠状断面上，均可清晰显示舌下神经的位置及毗邻结构，但以横断面和冠状面为佳。

Sectional Anatomy and MRI of the Hypoglossal Nerve

Objective：To provide practical anatomic data for the imaging diagnosis and surgical opera tion by observing the location, adjacent structures and recognition landmark of the hypoglossal nerve. Meth ods：36 sets of serial transverse sections, 18 sets of serial sagittal sections and 15 sets of serial coronal sections on the heads of Chinese adult cadavers were made by frozen section method; the transverse, sagittal and coronal imaging were obtained from 10 adult volunteers examined with 3D CISS sequences. Compared with the sec tional specimens, we observed the location, adjacent structures and recognition landmark of the hypoglossal nerve in the MR images. Results：The hypoglossal nerves run in the hypoglossal canals which are in the lateral basilar part of occipital bone on the transvers. In the sagittal section, the hypoglossal canal had a slightly ellip tical shape, which was located infra anterior to the cerebellum and between the petrosal sinus and atlanto oc cipital joint. To the medial of internal jugular vein, the external opening, which contained the hypoglossal nerve was in the superior lateral side of atlanto occipital joint in the coronary section through the external opening of hypoglossal canal. The recognition landmark of coronary section through the internal opening of hypoglossal ca nal was the birdg beak foramen in the lateral part of occipital bone. The medial side of the internal opening of hypoglossal canal was medulla oblongata and the lateral side was internal jugular vein, its superior side was jug ular foramen and its inferior side was atlanto occipital joint. Conclusions：The location and the adjacent struc tures of the hypoglossal nerve can clearly display in the transverse, sagittal and coronary sections. However, the transverse and coronary section is much better for showing the hypoglossal nerve.