Majos M, Polguj M, Stefańczyk L, et al. - Researchers investigated if the renal artery diameter could be objectively measured with the renal-aortic ratio (R-Ar), a novel parameter. Participants were 129 women and 125 men from whom computed tomography angiographic images were analyzed. By dividing the diameter of the main renal artery for each kidney by the aortic diameter, they calculated R-Ar. For the entire study group, R-Ar values ranged between 0.0863 and 0.5083, with 0.1150–0.5083 and 0.0863–0.4449 being the ranges of R-Ar values for women and men patients, respectively. The dependence of the diameter of renal arteries mainly on their number was shown in the analysis of the R-Ar values. The renal arteries of women vs men had larger relative diameters.