Fig. 1.

Abdominal CT scan oral and intravenous contrast material (A, B, C) showing: Staghorn calculi (red arrow) obstructing renal pelvis with associated hydronephrosis. Thin fistulae between the descending colon and left kidney (blue arrow). Infiltration and enlargement of the left psoas muscle, with abscess within it (green arrow). Extensive peri-nephric fat stranding and fibro-fat accumulation (yellow arrow). Calyceal dilatation giving a multiloculated appearance: “Bear's paw sign.”