Evaluation of vertebral artery variations and arterial dominance in cervical CT angiographic images in Iranian population

Abstract

Purpose: The aim of the present study was to determine the characteristics and variations in the origin of vertebral arteries (VA), its level of entry into the transverse foramen, VA diameter, Length of VA, and VA dominance. Methods: A total of 250 adult patients (143 males and 107 females) were enrolled (Mean age: 60.92±13.44) and scanned with Computerized Tomography angiography (CTA). Results: The VA entered the C6 transverse foramen in 97.8% of specimens. Abnormal entrance of VA was observed in 4.4% of specimens. The mean length of prevertebral (V1) right and left VA was 81.38±14.38 mm and 82.49±14.16 mm. The mean length of the intraforaminal segment (V2) of the right and left VA was 81.38±14.375mm and 82.49±14.162mm and showed sexual dimorphism. The mean diameter of the right and left VA was 3.297±0.85 and 3.676±0.88, respectively. We found 1(0.4%) left and 1(0.4%) right VA emerging from the aortic arch. The mean right and left VA diameters were 3.28 ± 0.83 mm and 3.6±0.88mm, respectively. A total of 90(0.36) patients were right dominant and 160(0.64) patients were left-dominant. The right VA of aortic arch origin entered the 4th cervical transverse foramina, whereas the left VA entered the 7th cervical transverse foramina. We found that 22(8.8%) of the right and 1 (0.4%) of the left vertebral arteries had distal origin. The results did not show any relationship between gender and origin of VA, diameter of VA, and level of entry. A significant relationship was observed between gender and VA length (P=0.0001). Discussion: The present study confirms the presence of anomalous in the VA route. Knowledge of such anatomical variations is important in interpreting CTA and may reduce the risk of intraoperative VA injury