CT of the abdomen-

A cuffed catheter is positioned within the urinary bladder and the urinary bladder is empty. Ventral to the cuff of the urinary catheter a spiculated mineral attenuating calculus is noted. After contrast administration small round well defined areas are noted in the renal cortex of both kidneys. However both kidneys present a bilaterally symmetric uniform nephro- and pyelogram. There is no evidence of renal or ureteral calculi. There is no evidence of pyelectasia or hydroureter. Duplication of the pre-renal caudal vena cava is noted. Level with the renal veins the veins unite to a single caudal vena cava. Both ureters pass ventral to the vena cava respectively.