Introduction. Urinary stone disease is one of the most significant urologic diseases, since its prevalence increases annually, which makes it necessary to study and improve effective preventive measures, diagnostic methods and to implement new treatment interventions.
Aim: to study changes in blood flow in the renal cortex and medulla in patients with ureteral stones using CT perfusion.
Materials and methods. From 2017 to 2019, a total of 53 patients with upper ureteric stones were evaluated at the Russian-Japanese Center for Imaging and the Institute of Urology and Reproductive Health of the FGAOU VO I.M. Sechenov First Moscow State Medical University. Preoperatively, all patients underwent CT perfusion. The study was performed on a Toshiba Aquilion One 640 in volume mode with a slice thickness of 0.5 mm. In this study, blood flow changes were evaluated depending on the degree of dilatation of collecting system.
Results. In patients without dilatation of the collecting system, the average values of cortical and medullary blood flow and blood volume were within normal values. In patients with a dilatation of collecting system, there were significant differences cortical and medullary blood flow between the affected renal unit and contralateral side (27% and 34%, respectively). A decrease in cortical and medullar perfusion by 55% and 58%, respectively, in patients with the dilatation of calyxes was more pronounced in comparison with a decrease in perfusion in patients with the dilatation of only the ureter and pelvis.
Conclusion. CT perfusion performed on the 640-slice CT scan allows an objective assessment of changes in renal blood flow in patients with ureteric stones.

Keywords: computer tomography, CT perfusion, ureteric stones, renal blood flow, extracorporeal shock-wave lithotripsy, urinary stone disease, ureteroscopy