Contradictory renal function measured with mercaptoacetyltriglycine diuretic renography in unilateral hydronephrosis.

Purpose: We studied apparently supranormal renal function in hydronephrotic kidneys, as measured by 99mtechnetium mercaptoacetyltriglycine renography.

Materials And Methods: We retrospectively reviewed the clinical history, ultrasonography and renography of 29 children.

Results: Of the 29 children 7 had greater than 50% relative function in the hydronephrotic kidney. This finding was independent of patient age, gender, degree of hydronephrosis or obstructive pattern. Of these 7 cases 6 occurred on the right side (p < 0.05 versus a large registry).

Conclusions: In most cases supranormal renal function is caused by a technical problem, likely the inadequate background subtraction of mercaptoacetyltriglycine in the liver.