Volume CT Digital Subtraction Angiography Study Of The Circle Of Willis

Objective:To investigate the morphology variation of the circle of Willis by volume CT digital subtraction angiography (VCTDSA), and to determine whether age- or gender- or disease- or race-related differences exist in the circle's anatomy.Methods:699 cases were inspected by VCTDSA, who were grouped according to disease: 280 cases of the normal group, 155 cases of cerebral infarction group, 264 cases of cerebral aneurysm group, 385 cases of male, 314 cases of female. Utilization of 3D volume rendering (volume render, VR) display showed anatomical structure of the circle of Willis to observe its morphological variation, and compared with former studies.Results : There was no gender- or age-related difference of the morphological variation of the normal group. 72.9% cases demonstrated a complete anterior part of the circle, 22.6% cases demonstrated a complete posterior part of the circle, and 19.6% cases demonstrated an entirely complete circle of Willis.There was no gender- or age-related difference of the morphological variation of the cerebral infarction group. 68.3% cases demonstrated a complete anterior part of the circle, 19.4% cases demonstrated a complete posterior part of the circle, and 18.1% cases demonstrated an entirely complete circle of Willis.There was no gender- or age-related difference of the morphological variation of the cerebral aneurysm group. 68.1% cases demonstrated a complete anterior part of the circle, 28.8% cases demonstrated a complete posterior part of the circle, and 26.1% cases demonstrated an entirely complete circle of Willis.There was no gender- or age-related difference of the morphological variation of all the cases. 70.1% cases demonstrated a complete anterior part of the circle, 24.1% cases demonstrated a complete posterior part of the circle, and 21.7% cases demonstrated an entirely complete circle of Willis. There was age-related difference in the complete rate of the posterior part and the entirely circle.Comparing with former studies, there was more anterior variant d and more posterior variant e in this study. The entire complete rate was close to autopsy studies.Conclusion:Increase with age, the complete rate of the circle of Willis decline. There is more anterior variant h in aneurysm group. There is no race-related difference in the morphological variation of the circle, but there is race-related difference in the complete rate of the entire circle.