A retrospective study of intracranial vertebrobasilar system morphometry and its variations using non-contrast magnetic resonance angiogram (MRA)

The vertebrobasilar system (VBS) provides 30% of the blood supply to the posterior cerebral fossa. Morphological changes are associated with an increased risk of atherosclerosis and aneurysm development, resulting in cerebrovascular and cardiovascular disorders. This study assesses VBS morphometry and its variations in imaging analyses. A morphometric analysis was performed on 100 adult patients aged 20 to 60 years using non-contrast magnetic resonance angiography (MRA). Demographic information and multiple VBS parameters were documented. The mean length of the basilar artery across all 100 cases was 31.31 mm, with a diameter varying from 3.01 mm to 3.12 mm. The diameters of the right and left vertebral arteries were 2.35 mm and 2.50 mm, respectively. We noted deviations in the branching pattern of the basilar artery at the termination site in 30% of cases, potentially influencing hemodynamics and elevating the likelihood of aneurysm formation. Vertebral artery hypoplasia and atresia were observed in 37% and 2% of patients, respectively. Asymmetrical vertebral arteries led to variable courses of the basilar artery, specifically "C" and "S" configurations, noted in 49% and 11% of cases, respectively. Statistically significant changes were observed in VBS dimensions, basilar artery angle, and the course between age and high-risk groups. No substantial difference was noted between the genders. The findings furnish foundational data for neurosurgeons and radiologists in the diagnosis of cerebral and cardiovascular disorders, as well as in the planning of neurosurgical interventions in the posterior cranial fossa.