滑车神经断层解剖与MRI

Sectional Anatomy and MRI of Human Trochlear Nerve

目的：探讨滑车神经在MRI图像上的识别，为滑车神经相关疾病的影像学诊断和临床治疗提供形态学依据。方法：选取国人成年尸体头部标本51例，以冷冻切片法分别制成连续横断层标本36例和连续冠状断层标本15例；采用3D—CISS序列，结合3D—TOF序列，对20名正常体检者及23例眼运动神经麻痹患者行1．5T磁共振扫描；应用3．0TMRI扫描仪，获取10例志愿者头部的SE序列T2WI图像；在上述连续断层标本和MRI图像上，观察分析滑车神经的位置、走行、毗邻及识别标志等。结果：在横断面上，滑车神经起始段走行在上髓帆后部的四叠体池内，其外侧为小脑幕切迹，后方为小脑上动脉；其环池段绕中脑大脑脚两侧的环池走行，由背侧转至腹侧。在冠状断面上，滑车神经环池段位于小脑幕下方，其外上方有大脑后动脉；其海绵窦段走行在蝶骨体两侧的海绵窦外侧壁，动眼神经的外下方。结论：横断面能较好地显示滑车神经的起始段和环池段，而冠状断面则能清晰地显示其海绵窦段。

Objective ： To explore the identification of trochlear nerve on MRI images in order to provide practical anatomic data for the imaging diagnosis and clinical treatment of the trochlear nerve related diseases. Methods：36 sets of serial transverse sections and 15 sets of serial coronal sections on the heads of Chinese a- dult cadavers were made by frozen section method;20 subjects and 23 patients with ocular motor nerve palsy were examined with 3D - CISS and 3D - TOF sequences; MR T2 weighted images were obtained froml0 vol- unteers examined with SE sequences; The serial sectional specimens and MRI images were used to investigate the location, course, adjacency and representative structures. Results：According to the transverse sections, the initial segment of the trochlear nerve ran in the cistern of corpus quardrigemina after passing through the sides of superior medullary velum. There were tentorial incisure on its lateral side and superior cerebellar fossa on its posterior side; however, the cisterna ambiens segment of the trochlear nerve ran in the cistema ambiens which located around the cerebral peduncle and turn to ventral side. According to the coronal sections, the cisterna ambiens segment was located under the tentorial incisure. There was posterior cerebral artery on the superior lateral side; In the cavernous sinus segment, the trochlear nerve was found on the lateral wall of cavernous si- nus which located on the both sides of body of sphenoid bone and in the inferolateral side of oculomotor nerve. Conclusions：The initial segment and the cisterna ambiens segment are well displayed on the transverse plane, while the cavernous sinus segment can be seen well on the coronary plane.