Diuretic urography in the assessment of obstruction of the pelvi-ureteric junction.

Twenty adult patients with urographic evidence of unilateral, moderately wide renal pelves were examined by routine and diuretic urography. Planimetry of the corresponding calyx system of the two examinations was performed. An increase in size by more than 20 per cent following osmotic diuresis indicated an obstruction of the pelvi-ureteric junction in kidneys with moderately wide renal pelves. Diuretic urography may be useful to diagnose obstruction as a cause of moderately wide renal pelves and to assess operative results.