MATERIAL and METHODS: Cranial Tomography Angiography (CTA) of 168 individuals were analyzed retrospectively. The individuals included in the study were divided into four groups according to the diagnosis. Group 1 included 40 individuals who were diagnosed with HT, Group 2 included 43 individuals who were diagnosed with DM, Group 3 included 42 individuals who were diagnosed with DM and HT, and Group 4 was the control group and included 43 individuals. The diameter and length measurements of the vessels forming the WP were included in our study.

RESULTS: According to the results of the Kruskal Wallis H test, in female patients statistically significant differences were detected in the diameter measurements of the right and left A1 segment of the ACA, the diameter measurement of the left A2 segment, the diameter measurements of the right and left P1 and P2 segments of the ACP, the diameter measurements of the right and left AComP. (p<0.05), in male patients statistically significant differences were found in the diameter of the right A1 segment of the ACA, the diameter and segment length measurements of the right and left P1 segments of the ACP, of the right and left P2 diameter measurements, and segment length measurements of the left AComP (p<0.05).

CONCLUSION: We also found that the vessel diameters were similar in the HT, DM and HT+DM groups, and smaller than the control group. In addition, we think that knowing WP morphometric measurements will both guide the radio-anatomical evaluations to be made and increase the level of microanatomical knowledge in surgical treatment. Keywords : Computed tomography angiography, Polygon of Willis, Hypertension, Diabetes mellitus, Diameter