Comparative methods of diuretic renography in the evaluation of ureteropelvic junction obstruction

Abstract EN

Objectives : To compare the diagnostic impact of two diuresis renography techniques for the evaluation of suspected upper urinary tract obstruction in children.

Methods: A total of 67 children with questionable obstruction were evaluated by diuresis renography.

They were assigned to two standardized diuresis renography protocols.

The protocols were identical, except for the time of frusemide (F) injection.

In the F+20 scans, frusemide was given 20 minutes after the Tc-99m (Diethylenetriamine penta acetic acid) radiopharmaceutical.

With the modified F-15 scans frusemide was injected 15 minutes before renography.

Kidneys were classified as nonobstructed, equivocal and obstructed, based on a diuresis renography time-activity curve.

Results : Because one child had a solitary kidney, the total number of kidneys studied for outcome was 133.

The overall agreement between the two studies was 84 % (112 cases).

The agreement in the non-obstructed group was 98 % while the agreement in the obstructed group was 89 %.

The number of equivocal cases dropped from 23 kidneys (17 %) in the F+20 to 8 kidneys (6 %) in the F-15 study.

Conclusion : The timing of the frusemide injection had a significant impact on the renography results when evaluating children with suspected upper urinary tract obstruction.

The F-15 proved to be reliable in the assessment of patients with suspected ureteropelvic junction obstruction and reduced the number of equivocal cases.