The value of radioisotope renography in the followup of patients operated upon for hydronephrosis.

Isotope renography and excretory urography were perfored routinely before and 3 months after an operation on 21 patients with hydronephrosis. A year postoperatively all patients again underwent renography. Renography is a valuable and reliable method to estimate the results of an operation. By 3 months postoperatively the renograms revealed improved renal function and drainage in 75 per cent of the cases.