The authors summarize briefly the mathematical method for obtaining transit functions and times in dynamic renal scintigraphy. They work out minimal, medium and maximal transit times for the whole kidney, the parenchyma and pelvis. Based on values and the differences of these times, it is possible to assess whether the disorder is at the parenchymatous level or in the hollow system (dilatation or obstruction). This can contribute in a significant way to the differential diagnosis of causes of nephropathies and uropathies.

        Key words: dynamic renal scintigraphy - transit functions and times