Anatomical Variations in Circle of Willis in Patients Undergoing CT Cerebral Angiography in a Tertiary Hospital in Nepal: A Descriptive Cross-sectional Study

Introduction: Variation in Circle of Willis is a commonly encountered entity in patients undergoing computed tomography angiography, identification of which is crucial in the management of patients with vascular pathologies. The aim of the study was to find out the anatomical variations in the Circle of Willis in patients undergoing Computed Tomography cerebral angiography in a tertiary hospital in Nepal.   Methods: This is a descriptive cross-sectional study involving 95 patients using convenient sampling techniques who were sent to the Department of Radiology and Imaging, Tribhuvan University Teaching hospital, for further evaluation of suspected vascular pathologies in the brain from April 2017 to September 2017. Ethical approval was taken from the Institutional Review Committee of the Institute of Medicine with reference number 326 (6-11-E). CT angiographic images of these patients were evaluated for the presence of variations in Circle of Willis, aneurysms, and other vascular pathologies. Data were analyzed using SPSS.   Results: Among 95 subjects included in the study, the anatomical variations in the arteries of Circle of Willis was seen in 52 (54.7%) patients, hypoplastic posterior communicating artery being the most common variation 33 (34.7%). The aneurysm was seen in 22 (23.2%) of cases.   Conclusions: CT Angiography is a commonly performed imaging modality for suspected cases of cerebral aneurysms and various other vascular pathologies. Multidetector computed tomography can effectively detect variations in arteries of Circle of Willis, recognition of which is crucial in operative management of vascular pathologies.