Pelviureteric junction obstruction. The value of a post-micturition view in 99mTc DTPA diuretic renography.

Eighty-one 99mTc DTPA renograms were performed in 31 children who had previously undergone pyeloplasty for pelviureteric junction obstruction (PUJ). A post-micturition image following a diuretic stimulus excluded obstruction in 50% of the patients in whom the frusemide T75 was abnormally prolonged beyond 10 min. Evaluating the 99mTc DTPA renogram and the response to a diuretic without both changing the patient's position and ensuring an empty bladder may lead to incorrect diagnosis of PUJ obstruction.