Classical Pattern of the Cerebral Arterial Circle of Willis in a Nigerian Population Using Contrast Enhanced Computed Tomography Scan

Abstract

Studies have highlighted the significance of patterns of the circle of Willis (major arterial supply to the brain) observed from different parts of the globe. This research was carried out to identify and document the patterns of the cerebral arterial circle of Willis, which are lacking in the Nigerian population. A total of 512 normal brain CT images of Contrast Enhanced Computed Tomography (CECT) scans from the CT scanner in the Radiology Department of Jos University Teaching Hospital (JUTH) were obtained and reviewed using proportionate random sampling probability technique with their ages graded from <1 year to >91 years between January 2013 to July 2015. Data collected out of the 512 brains examined showed that the commonest pattern was 39.84%, which conforms to the classical, standard or complete circle of Willis with all the vessels intact as those in the text books of Anatomy while the rest (60.16%) were observed to be morphologically incomplete circle of Willis. The CECT scan method has established for the first time the occurrence of forms of the circle of Willis in a Nigerian sampled population with the classical pattern (39.84%) as the most common. This finding agrees with reports from studies with cadaveric Gross Dissection (GD), Magnetic Resonance Imaging (MRI) and the injection techniques.