Evaluation of ureteropelvic junction obstruction (UPJO) by diuretic renography

Of 52 cases with 56 affected renal units having symptoms and signs suggestive of Ureteropelvic Junction Obstruction (UPJO) evaluated by conventional (F + 15) diuretic renography where frusemide is given 15 minutes post-injection of radiopharmaceutical m99TC.DTPA.F + 15, twelve (21%) showed a good clearance (group A), 16 (28%) showed partial (group B) and 28 (50%) a poor clearance pattern (group C) indicating a definite obstruction. A high flow (F-15) diuretic renography where frusemide is given 15 minutes prior to the radiopharmaceutical m99TC.DTPA, was done in 23 cases with 27 affected renal units. Eleven renal units showed a good clearance (group A). Of these, 7 (64%) showed a persistent good clearance, 3 (27%) converted to poor clearance and 1 (9%) to partial clearance pattern. Of 8 renal units in group B, 5 (63%) converted to poor clearance and two (25%) to good clearance on F-15 and one remained unchanged. All renal units which presented as poor clearance (group C) on conventional (F + 15) diuretic renography remained unchanged on high flow (F-15) diuretic renography. In majority of cases conventional (F + 15) renography gave a reliable assessment of the upper tract drainage, however, since equivocal group was resolved by the F-15 and the intermittent obstruction group was definitely diagnosed, high flow (F-15) diuretic renography was more conclusive in assessment as compared to F + 15.