Tsutsumi Satoshi, Ono Hideo, Ishii Hisato, Yasumoto Yukimasa
Department of Neurological Surgery, Juntendo University Urayasu Hospital, 2-1-1 Tomioka, Urayasu, Chiba, 279-0021, Japan.
Division of Radiological Technology, Medical Satellite Yaesu Clinic, Tokyo, Japan.
Childs Nerv Syst. 2019 Apr;35(4):683-687. doi: 10.1007/s00381-019-04103-5. Epub 2019 Feb 28.
The morphology of the vertebral artery (VA) segment at the suboccipital dural penetration site has little been explored with magnetic resonance imaging (MRI). Therefore, the aim of this study was to examine the structure using MRI.
In total, 94 patients underwent thin-sliced, contrast MRI in the axial, coronal, and sagittal planes involving the atlas, axis, occipital bone, and V3 and V4 segments of the VA.
The VA segment at the suboccipital dural penetration site was well-delineated in 93% on the axial images and in 95% on the coronal images. The axial images showed that 82% of the VA penetration sites were located in the middle third of the dural sac. Meanwhile, the coronal images revealed that the heights of both VA penetration sites were located at the same level in 87%. The axial VA penetration angle, which is formed by the VA and tangential line of the dural sac, was 66 ± 11.9° on the right side and 61 ± 14.1° on the left side. The coronal VA penetration angle, which is formed by the tangential line of the VA and dural sac, was 111 ± 24.6° on the right side and 112 ± 19.9° on the left side.
The morphology of the VA segment is considerably variable at the suboccipital dural penetration site, while most penetration sites are located in the middle third of the dural sac on axial MRI. These should be assumed during surgeries around the suboccipital VA penetration site.
枕下硬脑膜穿入部位椎动脉（VA）节段的形态学在磁共振成像（MRI）研究中较少被探索。因此，本研究旨在利用MRI检查其结构。
总共94例患者接受了包括寰椎、枢椎、枕骨以及VA的V3和V4节段的轴向、冠状面和矢状面的薄层增强MRI检查。
在轴向图像上，93%的枕下硬脑膜穿入部位的VA节段显示清晰，在冠状面图像上为95%。轴向图像显示，82%的VA穿入部位位于硬膜囊的中三分之一处。同时，冠状面图像显示，87%的VA穿入部位的高度处于同一水平。由VA与硬膜囊切线形成的轴向VA穿入角度，右侧为66±11.9°，左侧为61±14.1°。由VA切线与硬膜囊形成的冠状面VA穿入角度，右侧为111±24.6°，左侧为112±19.9°。
枕下硬脑膜穿入部位的VA节段形态差异较大，而在轴向MRI上，大多数穿入部位位于硬膜囊的中三分之一处。在枕下VA穿入部位周围的手术中应考虑到这些情况。
