Which arteries are measured bilaterally when performing an ABI?

• A. Posterior tibial and dorsalis pedis arteries
• B. Brachial and radial arteries
• C. Carotid and femoral arteries
• D. Renal and iliac arteries

Answer: (A)

For an ankle–brachial index, the key step is measuring the systolic pressures in the arteries at the ankle on both legs. Those two arteries are the posterior tibial and the dorsalis pedis, and taking measurements from both sides ensures you can compare each leg’s ankle pressure to the arm pressure (from the brachial arteries) to assess for peripheral arterial disease. The other arteries listed aren’t used for the ankle measurements in the ABI. Measuring both ankle arteries bilaterally helps detect unilateral disease and provides a reliable index when you divide by the arm pressure.