[Ureteropelvic stenosis in infancy. The value of diuresis sonography compared with diuresis excretory urography].

Examinations under conditions of diuresis produced by drugs can be useful to differentiate pyelo-ureteric obstruction from a dilated collecting system with normal flow. 22 infants with 42 kidneys showing moderate dilatation of one of both renal collecting systems were examined by sonography and excretory urography under conditions of diuresis and the results were compared. Depending on the radiological appearances and contrast clearance rates, four diagnostic groups could be identified; these also differed significantly on the sonographic examinations. In general, there was good agreement between the two methods. Carefully performed, diuresis sonography will clearly distinguish between urodynamically significant obstruction from a wide but non-obstructive collecting system. The number of radiographic examinations can therefore be reduced in these patients.