How is peripheral artery disease diagnosed? 
The most common test for PAD is the ankle-brachial index (ABI). The ABI compares the blood pressure in your legs and arms (brachial means "of the arm") using a blood pressure cuff. If the pressures are different, it could mean you have PAD.

If the ABI shows that you may have PAD, your doctor may do other tests. The following tests can help show the location of the blocked artery and how serious the blockage is.

  • Duplex Doppler ultrasound — This test uses sound waves to create a picture of the arteries. This type of ultrasound can also show if blood is flowing smoothly through the arteries.
  • Magnetic resonance imaging (MRI) — Radio waves in a magnetic field are used to create flat or three-dimensional pictures of the arteries. If you have a pacemaker or implantable cardioverter defibrillator (ICD), be sure to check with your doctor before having an MRI.
  • Angiography — For this test, you are given a local anesthetic. Then, a special dye is injected into the artery through a small tube called a catheter. The dye shows up on x-rays and helps determine which arteries are narrowed or blocked.
  • Computerized tomography angiography (CTA) — For CTA, the dye is injected into a blood vessel, and x-rays are taken from different angles. Then, a computer analyzes the x-rays to form a three- dimensional picture of the arteries.