Diagnosis at Mayo Clinic begins with:
- A physical exam that includes your doctor listening through a stethoscope for sounds that may mean the artery to your kidney is narrowed
- Questions about your medical and family history
- Blood tests to evaluate kidney function and exclude other conditions
Doctors who specialize in the interpretation of medical images (radiologists) conduct tests to check your blood vessels and kidneys. You may need one or more of the following imaging tests to find the narrowing in the renal artery and determine its severity:
- CT scan. During a CT scan, an X-ray machine linked to a computer creates a detailed image that shows axial (cross-sectional), coronal and sagittal images of the renal arteries. You may receive a dye injection to show blood flow.
- Magnetic resonance angiography (MRA). MRA uses radio waves and strong magnetic fields to produce detailed 3-D images of the renal arteries and kidneys. A dye injection into the arteries outlines blood vessels during imaging.
- Ultrasound. High-frequency sound waves help your doctor see the arteries and kidneys and check their function. This procedure also helps your doctor find blockages in the blood vessels.
- Renal arteriogram. This special type of X-ray helps your doctor check blood flow and find the blockage in the renal arteries. Before an X-ray is taken, doctors inject a dye into the renal arteries though a long, thin tube (catheter) to outline the arteries and show blood flow more clearly. This is often performed at the time of restoring the blood vessel opening with a stent.
Read more about CT scan and ultrasound.