Robert L. Lebowitz, M.D. Children' s Hospital, Harvard Medical School Boston, Massachusetts

Prenatal diagnosis of hydronephrosis. Bilateral duplex kidneys. Right lower pole reflux on VCUG with a large left ureterocele (figure 1). IVP with a catheter in the bladder to prevent reflux shows a normal left lower pole, and a nonfunctioning left upper pole (figure 2). The left lower pole ureter is "wrapped around" its dilated upper pole mate.