Medullary CT enhancement in acute renal artery occlusion.

The diagnosis of traumatic renal artery occlusion by CT is based on finding the cortical rim sign, nonopacification of the pelvocalyceal system, and occasionally direct visualization of the thrombosed renal artery. We present four patients with renal artery occlusion who have an unusual pattern of medullary enhancement that has a vermiform and spoke-wheel appearance. It is important to realize that this enhancement does not represent functional renal tissue with a partially occluded renal artery. Instead, it is part of the spectrum of findings seen with complete occlusion of the renal artery.