Ono Kenichiro, Arai Hajime, Endo Toshitaka, Tsunoda Akira, Sato Kiyoshi, Sakai Tatsuo, Makita Junichi
Department of Neurosurgery, Juntendo University, Tokyo, Japan.
AJNR Am J Neuroradiol. 2004 Apr;25(4):623-6.
The abducent nerve is difficult to identify reliably and consistently with conventional radiologic techniques. In this study, a 3D fast asymmetrical spin-echo MR imaging technique was used to obtain detailed images of the abducent nerve in normal volunteers.
The 3D fast asymmetrical spin-echo MR protocol was used to image the abducent nerves in 24 normal volunteers by using a 1-mm section thickness in the tilted axial and parasagittal planes. The microanatomy of the abducent nerve within Dorello's canal was also demonstrated in a cadaver study.
In 24 normal volunteers, the anatomy of 47 abducent nerves was clearly depicted on MR images. The length of the cisternal segment of the abducent nerve, extending from the brain stem to its dural foramina, ranged from 6.7 to 19.6 mm (mean, 13.1 mm). The abducent nerves were at an angle of 5 to 90 degrees (mean, 24.5 degrees) to the clivus. CSF evagination was detected in the region of Dorello's canal in 36 (77%) of 47 abducent nerves. The length of CSF evagination varied: 0.9 mm in five nerves, 1.0 to 1.9 mm in 18 nerves, 2.0 to 2.9 mm in eight nerves, and 3.0 mm or more in five nerves. Histologic examination of serial sections of the abducent nerve revealed that the petroclival segment of the nerve was covered by an envelope composed of an arachnoid cell layer.
The course of the abducent nerve was reliably identified using the 3D fast asymmetrical spin-echo MR protocol and a histologically proven arachnoid envelope around the petroclival segment of the nerve was shown as CSF evagination into Dorello's canal by MR imaging.
采用传统放射学技术难以可靠且一致地识别展神经。在本研究中，使用三维快速非对称自旋回波磁共振成像技术获取正常志愿者展神经的详细图像。
采用三维快速非对称自旋回波磁共振成像方案，在倾斜的轴位和矢状旁位平面以1毫米的层厚对24名正常志愿者的展神经进行成像。在一项尸体研究中也展示了多雷洛管内展神经的微观解剖结构。
在24名正常志愿者中，磁共振图像清晰显示了47条展神经的解剖结构。展神经脑池段从脑干延伸至硬脑膜孔，长度范围为6.7至19.6毫米（平均13.1毫米）。展神经与斜坡的夹角为5至90度（平均24.5度）。在47条展神经中的36条（77%）的多雷洛管区域检测到脑脊液外突。脑脊液外突的长度各不相同：5条神经为0.9毫米，18条神经为1.0至1.9毫米，8条神经为2.0至2.9毫米，5条神经为3.0毫米或更长。展神经连续切片的组织学检查显示，该神经岩斜段被由蛛网膜细胞层组成的包膜覆盖。
使用三维快速非对称自旋回波磁共振成像方案可可靠识别展神经的走行，并且通过磁共振成像显示，神经岩斜段周围经组织学证实的蛛网膜包膜表现为脑脊液向多雷洛管内突出。
