IMAGING OF ANATOMICAL VARIANTS OF CIRCULUS ARTERIOSUS CEREBRI: A PROSPECTIVE CROSS SECTIONAL OBSERVATIONAL STUDY IN TERTIARY CARE TEACHING HOSPITAL OF TELANGANA IN INDIA

Abstract

Background: The Circulus Arteriosus Cerebri (CAC), also known as the Circle of Willis, is a complex 
network of blood vessels located at the base of the brain that plays a critical role in maintaining cerebral 
blood flow. The CAC is known for its anatomical variability, and understanding these variants is essential for 
effective diagnosis and treatment of cerebrovascular diseases. Aim: In this study, we aimed to prospectively 
examine the imaging of anatomical variants of CAC. Methods: We conducted a cross-sectional 
observational study of patients who underwent computed tomography angiography (CTA) or magnetic 
resonance angiography (MRA) of the brain. We recorded the demographic details of the patients and 
analyzed the imaging findings related to CAC. Results: A total of 250 patients were included in the study. 
The mean age of the patients was 50.8 years (SD=12.6), and 58% were male. We found anatomical 
variations of CAC in 78% of the patients. The most common variant was hypoplasia of the posterior 
communicating artery (42%), followed by fetal-type posterior cerebral artery (25%), and duplication of the 
anterior cerebral artery (18%). We also observed various other less frequent anatomical variants such as 
fenestration of the middle cerebral artery, absence of the anterior communicating artery, and asymmetrical 
distribution of the vertebral arteries. Conclusion: This study provides important insights into the prevalence 
of different anatomical variants of CAC, which can aid in better understanding the cerebrovascular anatomy 
and in the diagnosis and management of cerebrovascular diseases.