Ultrasonic diagnosis of obstructed renal duplication and ureterocele.

The diagnoses of complete obstruction in a duplicated renal collecting system and ureterocele can be made with a high degree of confidence by ultrasound. Two children presenting with abdominal masses were examined by gray scale ultrasonography which demonstrated large cystic masses dorsal to and displacing the lower pole of the kidney ventrally and laterally. In one patient the dilated ureter terminated in a ureterocele. Ultrasonography is the appropriate imaging modality for this disease process, though it generally becomes the complementary study to excretory urography in the diagnosis of an obstructed duplicated system. The dilated pelvis and ureter can be imaged to ultrasonography even when their presence is only implied on an excretory urogram. Finally, the cystic nature of a ureterocele, as well as its relationship to the ureter and bladder, makes ultrasonography an ideal technic for evaluating this anomaly.