Skull Anatomic Landmarks for Retrosigmoid Craniotomy in a Chinese Cohort: A 3D-Computed Tomography Study in Vivo.

AIM This study was designed to determine the anatomic position of the asterion and the relationship between the asterion and the transverse sigmoid sinus junction (TSSJ) in a Chinese cohort. MATERIAL AND METHODS Venous computed tomography (CT) angiography was performed in 32 patients to simultaneously obtain 3D-CT volume rendering images of the cranial bone and the dural sinus. The relationship between the TSSJ and the asterion was analyzed. RESULTS The distance from the asterion to root of zygoma (ROZ) was 54.6 ± 5.50 mm on the right side and 54.1 ± 5.42 mm on the left side. The asterion was 49.10 ± 3.56 mm above the tip of mastoid process (TOP) on the right side and 48.70 ± 2.23 mm on the left side. The asterion's position was at the junction of the transverse-sigmoid sinus complex in 44 cases, below it in 19 cases, and above it in one case. CONCLUSION 3D-CT volume rendering imaging is capable of accurately and simultaneously visualizing the bony landmark and the dural sinus structure outline in vivo, thus offering a new option for anatomic research and morphometric investigation. The accurate location of asterion can be found using the root of the zygoma and the tip of the mastoid process.