[Role of scintigraphic tests in upper urinary tract dilatation in children]

The diuresis renography has an important place in the management of upper urinary tract dilatation in children. This non-aggressive and low irradiant exploration is very helpful to determine if hydronephrosis is obstructive or not and to evaluate the renal function impairment. The protocol of exam must be particularly rigorous and interpretation should take into account physiopathological factors that influence provocated diuresis. A well patient hydration and if necessary a bladder catheter are required. The MAG-3 is the radiopharmaceutical of choice especially in newborn and infants. The furosemide administration at 20 minutes after radiotracer injection is the most commonly used protocol and is generally sufficient to classify the urinary dilatation. Equivocal cases and symptomatic forms can benefit from a modified protocol in which furosemide is administered 15 minutes before radiotracer injection (F-15). False positive tests may result from a marked dilatation or renal function reduction. The place of diuresis renography in management of neonatal hydronephrosis is controversial, particularly because of the dynamic and evolving nature of this pathology.