The ultrasonographic differentiation of obstructive versus nonobstructive hydronephrosis in children: a multivariate scoring system.

PURPOSE

We identified sonographic prognosticators to aid in distinguishing obstructive from nonobstructive hydronephrosis in children.

MATERIALS AND METHODS

Twelve sonographic variables were initially analyzed to determine significant associations between the variables and the presence of urinary tract obstruction as defined by diuretic radionuclide renography. The significant findings were subsequently subjected to logistic regression models to identify potential predictors for obstructive hydronephrosis.

RESULTS

The 7 variables associated with a significantly higher risk of urinary tract obstruction were increased echogenicity, parenchymal rims 5 mm. or less, contralateral hypertrophy, resistive index ratio 1.10 or greater, resistive index difference with diuresis of 70% or greater, ureter diameter 10 mm. or greater and aperistaltic ureter. These variables were used for the development of a multivariate scoring system.

CONCLUSIONS

The obstructive scoring system shows promise as a screening method for the sonographic differentiation of obstructive from nonobstructive hydronephrosis in children.