Aims: To compare the quality of MR of urography with intravenous urography, sonography and scintigraphy of urinary tract, presentation of MR urography as a possible substitution of so far used examinations in preoperation diagnostics of anomalies in upper urinary tract. Methods: static MR urography was used to examine 51 patients at the age of one month to 18 years with dilatation of upper urinary tract detected by sonography. In 12 of them a dynamic MR study of the kidneys was also performed. Magnetic urography was compared with elimination urography, sonography and dynamic kidney scintigraphy. The detection rate was evaluated within the framework of the complex preoperation examinations for different stages of urinary tract in patients up to 2, 6, 12 and 18 years, respectively. Results: in the total number of 36 kidneys, modified by hydronephrosis, magnetic urography was evaluated as more precise in 18 cases, elimination urography in eight and both examinations were considered equal in 10 cases. The imaging of megaureters by MR urography was more precise in 7 cases, elimination urography was at the same level six times and less precise in eight patients. The results differed in individual age categories. Sonography imaging of the kidney was good as well as for the lower portion of ureter but insufficient for the middle portion. The same course of excretion curves in dynamic excretion urography and dynamic scintigraphy of the kidney was reached in 6 patients. Conclusion: MR urography is capable to provide information on anatomy and function of the whole urinary tract in a single examination, being different from excretion urography by its ability of imaging and evaluating the hypofunctional part of the kidney. It represents a possibility to significantly reduce present examination which exerts a load upon the patient.

        Key words: magnetic resonance – urography – upper urinary passages – preoperation examination