ABI is Ankle-Brachial Index test. It compares the blood pressure in your ankles to the blood pressures in your arms to determine if person’s legs are getting the proper amount of blood supply. It is an important test for screening Peripheral Artery Disease (PAD). The test is safe and painless. It is similar to checking blood pressure in your arm but rahter it checks in all 4 extremities. During this test Pulse is detected by Ultrasound doppler device.