Comparison of the F+20 and F-15 Diuresis Technetium-99m Diethylenetriaminepentacetate Renography Protocols for Diagnosis of Ureteropelvic Junction Obstruction in Adult Patients with Hydronephrosis.

Introduction: Hydronephrosis (HDN) in adults is a common presentation and may be due to congenital ureteropelvic junction obstruction. Diuresis renography is the method of choice for differentiating a dilated unobstructed urinary system from a true obstruction. The aim of this study was to compare the F+20 protocol with F-15 protocol and see whether this new protocol can reduce inconclusive results.

Materials and Methods: It was a prospective, comparative study included 51 adult patients of primary HDN. Each patient underwent both F+20 and F-15 diuretic Technetium-99m diethylenetriaminepentacetate (Tc-DTPA) renography protocol studies. The results of diuretic Tc-DTPA renography studied in terms of obstructive, nonobstructive, or equivocal.

Results: A total 60 renal units (RU) with HDN were included in this study. The mean age of patients was 25.25 years. 36 RU presented with specific symptoms and 24 RU with vague symptoms or diagnosed incidentally. The equivocal results were significantly lower in F-15 protocol than F+20 protocol. The equivocal results in F+20 protocol were significantly higher with incidentally diagnosed HDN and patients presented with vague symptoms. Most of the equivocal results of F+20 protocol were converted into either obstructive or nonobstructive by the F-15 protocol.

Conclusion: The F-15 diuretic renogram protocol was associated with significantly less equivocal results than F+20 protocol. Moreover, F-15 protocol allowed clarification in cases of equivocal results of F+20 protocol. Therefore, we suggest the F-15 diuresis protocol as a single test for confirmation or exclusion of obstruction especially in the adult patient of HDN presented with vague symptoms or diagnosed incidentally.