[Age-dependency of isotope drainage in diuretic renograms].

OBJECTIVE

The aim of the study was to establish normal values of the isotope drainage in diuretic scintigrams for children of different age-groups. Isotope drainage was determined 30 minutes after the application of technetium- (99m)MAG 3 as well as 15 minutes after the following application of furosemide.

METHODS

We analysed the data from 274 investigations in sonographically normal renal units (RU) contralateral to kidneys with ureteropelvic junction obstruction or non-refluxing primary megaureters.

RESULTS

There was a significant age-dependency of isotope drainage during the first weeks of life. In 79 RU the results of the first diuretic renogramm were compared with the follow-up examinations. The reliability of the measurements was lowest in children initially investigated during the first six weeks of life. If both the investigations were performed thereafter, no significant difference was found between the results.

CONCLUSIONS

The isotope drainage of the sonographically normal contralateral RU seems to be a sufficient marker for the meaningfulness of the diuretic renogram. In urinary tract dilatation, mistakes regarding the interpretation of isotope drainage may be minimized by taking the measurements in the normal contralateral RU in account and by comparing them with age-referred normal values.