ABI Test

The Ankle-Brachial Index (ABI) test is a quick, non-invasive diagnostic tool that measures the ratio of blood pressure at the ankle to the blood pressure at the arm. To perform the test, a vascular surgeon or technician uses a Doppler ultrasound device to obtain blood pressure readings at both the brachial artery in the arm and the posterior tibial or dorsalis pedis arteries in the ankle. The ABI is calculated by dividing the ankle pressure by the arm pressure.
Vascular surgeons use the ABI to detect peripheral artery disease (PAD), a condition where narrowed or blocked arteries reduce blood flow to the legs. A normal ABI range is typically between 1.0 and 1.4. A score below 0.9 suggests PAD, with lower scores indicating more severe blockages. This test helps guide treatment decisions, such as lifestyle changes, medications, or interventions like angioplasty or surgery, to improve circulation and prevent complications like ulcers or limb amputation.