Renal CTA (CT of the arteries supplying blood to the kidneys) is performed for patients with elevated blood pressure or impaired kidney function suspected of being due to blockage of the arteries supplying the kidneys. 

Renal CTA is commonly used to visualize blood flow in the renal arteries (those supplying the kidneys) in patients with high blood pressure and those suspected of having kidney disorders. Narrowing of a renal artery is a cause of high blood pressure in some patients and can be corrected. A special computerized method of viewing the images makes Renal CT angiography a very accurate examination. Also done in prospective kidney donors.