Radionuclide studies in paediatric nephro-urology

The main tool of radionuclide techniques applied to paediatric uro-nephrology is the quantitation of function, which is an information not easily obtained by other diagnostic modalities. The radiation burden is low. Drug sedation is only rarely needed, whatever the age of the patient. Accurate determination of glomerular filtration rate can be obtained by means of an intravenous injection of Cr-51 EDTA and one or two blood samples. Tc-99m DMSA scintigraphy is an accurate method for evaluation of regional cortical impairment during acute pyelonephritis and later on, for detection of permanent scarring. Tc-99m MAG3 renography is nowadays a well-standardized method for accurate estimation of the split renal function and of renal drainage with or without furosemide challenge. This technique is particularly indicated in uni- or bilateral uropathies with or without renal and/or ureteral dilatation. Direct and indirect radionuclide cystography are two alternative modalities for X-ray MCUG. Their relative place in the strategy of management of vesicoureteral reflux is discussed.