CT Imaging of Renovascular Abnormalities

Abnormalities of the renal vasculature can manifest clinically as renal ischemia, renal insufficiency, and secondary hypertension. It is crucial to inspect the renal vessels not only for intrinsic or direct causes of vascular disease, but also for the enhancement pattern of the renal parenchyma as an indirect sign for vascular compromise. Although atherosclerotic renal artery stenosis is the most common renal vascular disease, fibromuscular dysplasia of the renal artery is the second most common and has characteristic imaging findings. Some vasculitides may affect the renal artery, and these need to be considered when there is abnormal soft tissue surrounding the artery or the kidney has a striated nephrogram. Arteriovenous abnormalities are divided into arteriovenous fistulas and arteriovenous malformations. A prominent renal artery in communication with a renal vein or a tangle of vessels associated with a prominent and early filling renal vein is very suggestive of a renal arteriovenous abnormality. Intraparenchymal renal artery aneurysms are not as common as main renal artery aneurysms, but the former can mimic a tumor, and a high index of suspicion is required to make the correct diagnosis. Many of these pathologies, in addition to renal trauma, can result in reduced perfusion or infarction of part of or all of the kidney.