Three dimensional magnetic resonance angiography of the circle of Willis: Anatomical variations in general Egyptian population

Abstract

Aimed to evaluate the different anatomical variations of the circle of Willis (COW) and determined average vessels diameters in general Egyptian population. We retrospectively evaluated the 3D-time of flight (TOF) MR angiogram (MRA) of 250 patients. One hundred and eighty patients out of them had no manifestations of cerebrovascular diseases included in the study. All of them were examined by 3D TOF MRA. The anatomical variants of the anterior and posterior components of the COW were studied. The complete COW were assessed and the diameters of all the components were measured. The correlation between the vessel diameters in relations to age and sex were evaluated. Complete anterior and complete posterior parts of the COW were seen in 68.3%, and 38.3%, respectively. Entirely complete COW was seen in 46.7%. The prevalence of entirely complete COW was slightly higher in females and young than males and older subjects. The study illustrated that there are statistically significant differences in some vessel diameters according to sex and age. The anatomical variants of the COW and the normal reference values for vessels diameter were determined in general Egyptian population based on measurements in 3DTOF MRA.