Role of renal Isotope Scanning In Evaluation of Postoperative Hydronephrosis

Abstract

Diuretic renal scintigraphy is a non-invasive method for diagnosis and following patients with obstructive uropathy and evaluating the effects of obstructive uropathy on the function of the obstructed kidney.

The distinction between mechanical obstructive uropathy and dilatation without obstruction is critical to the patient management as uncorrected obstructive uropathy can lead to loss of renal function.

In our study 21 patients with postoperative hydronephrosis, their ages range from 6 months-67 years old, were evaluated by the standard diuretic renography to evaluate its efficacy in differentiation between obstructive and non-obstructive cases of postoperative hydronephrosis.

The efficacy of standard diuretic renography in evaluation of obstructive uropathy was 76.2%. This low efficacy is due to high false positive results (about 24%), for such false positive cases modified (F- 15) diuretic renography was done which revealed absence of obstructive uropathy.

So modified (F'-15) diuretic renography is preferred over standard (F+20) diuretic renography in evaluation of cases with moderate to severe obstructive uropathy to avoid high false positive results.