Contemporary techniques for the radioisotopic evaluation of the dilated urinary tract.

Regardless of one's approach to the evaluation of hydronephrosis, nuclear imaging should be part of every child's evaluation, as it is the only imaging modality capable of providing significant renal function information. The studies can easily be performed on an outpatient basis without sedation. Diuretic renal scintigraphy is deceptively simple to perform, and commitment to detail is exceedingly important if the results are to be valid. Radioisotope transit time may also be helpful, although its calculation is technically difficult. Determination of the function of the kidneys individually is possible by several methods.