IJSR International Journal of Scientific Research 2277 - 8179 Indian Society for Health and Advanced Research ijsr-7-4-14948 Original Research Paper Circle of Willis & its variations - evaluation with magnetic resonance angiography. Ashwini Sankhe Dr. Dr. Mohd Javed Shaikh Dr. April 2018 7 4 01 02 ABSTRACT

 Background: Circle of Willis (COW) shows wide variation in different population groups. This study evaluates the anatomical variations in mixed

Indian population in tertiary hospital in Mumbai using three–dimensional time–of–ight (3D–TOF) magnetic resonance angiography (MRA).
Materials & Methods: Total 923 patients (471 men & 452 women; mean age, 52.3 years) underwent 3D–TOF MRA over a period of 18 months
using a 3.0 T MR scanner with review of images done using maximum intensity projection (MIP) and 3D volume rendered images.
Results: A complete COW was seen in 247 patients (135 females and 112 males). An incomplete anterior and posterior COW was found in 166
cases (17.98 %). The remaining 510 (55.25 %) subjects had partially complete COW conguration. The most common type of COW in a single
subject was anterior variant type A and posterior variant type E.
Conclusion: Our study provides an important reference source for COW variations in the regional population as a single center study and conrms
that conguration of the COW varies largely in general population. The anterior COW was complete in 79.95 % cases while the posterior COW was
incomplete in 70.53% cases. Complete COW was seen in 26.76 %. The prevalence of complete conguration of COW was slightly higher in
females than males.