Аim. The results of clinical observations and scientific studies of recent years indicate that abstinence from urination before the introduction of radiopharmaceuticals for PET / CT procedures is accompanied by a significantly lower flow of it into the bladder than after preliminary urination.
Purpose of the study. Comparative analysis of PET/CT metabolism of 18F-fluorodeoxyglucose at the level of the cingulate gyrus of the brain, different regions of the kidney parenchyma and in the bladder wall in individuals without nephrourological history, depending on the phase of the functional state of the bladder.
Materials and methods. The results of PET/CT of the whole body of 30 patients of the radiological center of the Tyumen Regional Oncological Dispensary, including 16 men and 14 women (median age 52.5 (38; 63) years), were analyzed, distributed randomly in three equal study groups: after urination, in the intermictory period and immediately after the appearance of the first urge to urinate.
Results. Signs of synchrony were revealed in the anatomical and metabolic activity of the cortical vegetative centers, certain regions of the renal parenchyma and the wall of the bladder in the process of urination, the movement of urine along the urinary tract, the stage of its accumulation in the bladder and preparation for urination.
Conclusion. The data obtained allow us to assume that the analyzed regions are equivalent areas of the general regulatory system that provides physiological processes in the organs of the urinary system. However, this fact requires further research and clarification.

Keywords: synchrony of metabolic manifestations, PET/CT, bladder, kidneys, brain