The ankle-brachial index test, also known as the ABI, is a non-invasive examination used to diagnose vascular conditions like peripheral arterial disease or PAD. The test measures and compares blood pressure in both the arm and ankle while at rest and after physical activity. The procedure can be used to detect changes in blood pressure in the legs, which indicates a potential blockage of in an artery in the lower leg.
An ABI is performed using a combination of a blood pressure cuff and Doppler ultrasound to both measure and view blood flow in the leg. The cuff measures blood pressure in the arm and ankle, which should be about the same if no blockage is present. Doppler ultrasound uses sound waves to create images of the artery as well as blood movement inside.
Patients typically lie down for the first part of the test, and a blood pressure cuff is placed on both the ankle and upper arm. A handheld device known as a transducer is also pressed on the skin above the artery in question to produce images of the vessel. In some cases, a patient may be asked to walk on a treadmill for a few minutes and then the test is repeated.
An ABI is a non-invasive way to determine whether there might be a blockage in an artery of the lower leg. If a blockage is detected, additional diagnostic tools may be used to pinpoint the location of the blockage. A procedure can then be performed to remove the blockage and restore healthy blood flow to the area. To learn more about the ABI, contact Northwest Vascular & Vein.