Extreme hydronephrosis due to uretropelvic junction obstruction in infant (case report).

BACKGROUND Hydronephrosis is the one of the most common congenital abnormalities of urinary tract. The left kidney is more commonly affected than the right side and is more common in males. AIM OF THE STUDY To determine the role of ultrasonography, renal dynamic scintigraphy and lowerdose computed tomography urography in preoperative diagnostic workup of infant with extreme hydronephrosis. CASE REPORT We presented the boy with antenatally diagnosed hydronephrosis. In serial, postnatal ultrasonography, renal scintigraphy and computed tomography urography we observed slightly declining function in the dilated kidney and increasing pelvic dilatation. Pyeloplasty was performed at the age of four months with good result. CONCLUSIONS Results of ultrasonography and renal dynamic scintigraphy in child with extreme hydronephrosis can be difficult to asses, therefore before the surgical procedure a lower-dose computed tomography urography should be performed.