Supine film from an intravenous urogram reveals a large solitary kidney on the right. The distal ureter is noted to cross the midline (arrows) emptying onto a hemitrigone in this patient with left renal agenesis.
Crossed-fused renal ectopia
Left retrograde ureterogram shows a cross-fused ectopia. The left kidney lies inferior and medial to the previously opacified right kidney (curved arrow). The distal right ureter (straight arrow) can be seen in its normal locationHorseshoe kidney.
Contrast-enhanced CT of the pelvis demonstrates a horseshoe kidney. Both renal pelves can be seen along the anterior border (curved arrows). The two kidneys are connected by functioning renal parenchyma.