The ankle-brachial index (ABI) calculator
The ankle-brachial index (ABI) is a simple, reliable means for diagnosing PAD in 5 minutes . Blood pressure measurements are taken at the arms and ankles using a pencil
shaped ultrasound device called a Doppler. A Doppler instrument produces sound waves (not x-rays) and is considered noninvasive because it does not require the use of needles or catheters. The ABI test is simple enough to be performed in any doctor's office or vascular laboratory. Not only is the ABI one of the most reliable tests for PAD, it is also the least expensive.
With the patient in a supine position, the physician takes blood pressure readings from both arms; he then takes blood pressure readings from both ankles with a sphygmomanometer and Doppler device. After determining the posterior tibial artery systolic pressures, the ABI value is calculated by dividing the higher systolic pressure in each leg by the higher systolic brachial pressure.
Ankle-Brachial Index (ABI) Worksheet
ABI scores should be interpreted as follows: