Sagittal US of the upper pole of the left kidney (above left) shows a duplicated kidney with hydronephrosis of the upper pole collecting system. Sagittal US of the bladder (above right) shows a large cystic structure at the base of the bladder. AP image of the bladder (below left) obtained at the start of filling of the bladder during a voiding cystourethrogram (VCUG) shows a large filling defect in the base of the bladder. AP image of the bladder (below right) obtained during the voiding phase of the VCUG shows the previously seen filling defect in the base of the bladder has everted out of the bladder and now appears as a contrast filled structure to the left of the bladder.
Pediatric Imaging 