BACKGROUND: The basilar artery (BA) is a crucial vessel in the posterior cerebral circulation, supplying blood to the occipital lobes, cerebellum, and brainstem. Variations in BA diameter can be indicative of pathological conditions and may serve as a predictive marker for cerebrovascular events. Despite the importance of these measurements, data on the normal BA diameter in the Black African population is limited. This study aims to establish baseline values for BA diameter in healthy adults in Enugu, southeast Nigeria, and to examine any potential gender differences.

METHODS: A cross-sectional study was conducted on 298 subjects (150 males, 148 females) at the University of Nigeria Teaching Hospital Ituku/Ozalla, Enugu State. Participants, referred for brain CT, had normal radiologist reports. Contrast-enhanced brain CT scans were performed using a 64-slice Brilliance Philips scanner. BA diameter was measured on axial images at the midpons level.

RESULTS: The participants had a mean age of 49.4 years (±14 years). The BA diameter ranged from 3.1mm to 5.5mm, with a mean of 4.2mm (±0.5mm). Males had a significantly larger BA diameter compared to females (p<0.05). Diameter increased with age in both genders.

CONCLUSIONS: This study provides reference values for BA diameter in a Nigerian population, highlighting a gender difference and age-related increase in diameter. These findings contribute to the understanding of BA geometry in Black Africans and can assist in diagnosing and managing cerebrovascular conditions.

KEYWORDS: Basilar artery diameter, brain scan, computed tomography, Enugu