Diagnosis

For diagnosis of renal artery stenosis, your doctor may start with:

• A physical exam that includes your doctor listening through a stethoscope over the kidney areas for sounds that may mean the artery to your kidney is narrowed
• A review of your medical history
• Blood and urine tests to check your kidney function
• Blood and urine tests to measure the levels of hormones that regulate blood pressure

Imaging tests commonly done to diagnose renal artery stenosis include:

• Doppler 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 and measure their severity.
• CT scan. During a CT scan, an X-ray machine linked to a computer creates a detailed image that shows cross-sectional 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 3D images of the renal arteries and kidneys. A dye injection into the arteries outlines blood vessels during imaging.
• Renal arteriography. This special type of X-ray exam helps your doctor find the blockage in the renal arteries and sometimes open the narrowed part with a balloon and/or stent. Before an X-ray is taken, your doctor injects a dye into the renal arteries through a long, thin tube (catheter) to outline the arteries and show blood flow more clearly. This test is mainly done if it's also likely that you need a small tube (stent) placed in your blood vessel to widen it.