Making the Diagnosis
Your doctor may do some of the following tests if PAD is suspected:
- blood tests to measure cholesterol and sugar levels
- blood flow measurement using a device called a Doppler ultrasound
- magnetic resonance angiography (MRA) scans to see clots in the arteries
- angiograms or arteriographs to get a closer look at the damaged blood vessels
Blood pressure tells the doctor how much blood is flowing to a certain area. To diagnose intermittent claudication, the doctor will see if the blood pressure in the ankle is 90% of the blood pressure in the arm. If the pressure in the ankle is less than this figure, the doctor will suspect that the leg artery is blocked.
The Doppler ultrasound can pick up the sound of blood going through the artery. The sound of the blood flow indicates how badly the artery is blocked. The sound signal is then converted into a picture. A color Doppler ultrasound can show different rates of blood flow.
During angiography, a dye solution that shows up on an X-ray is injected into the artery. X-rays are then taken to show the rate of blood flow and the diameter of the artery to see whether the artery is blocked. Doppler ultrasounds are used more often than angiography, as they are non-invasive and don't use X-ray radiation.