Ankle-brachial index, arterial Dopplers and duplex ultrasound
How to calculate and interpret the ABI and toe-brachial index, read Doppler waveforms, and use duplex thresholds for leg arteries, bypass grafts, carotids, renal arteries and veins, with the traps of calcified vessels.
Tier 2Medical sciences concept
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- The ABI is the bedside test for lower limb PAD: 0.90 or less diagnoses it. It also flags high cardiovascular risk.
- Over 1.40 means calcified, incompressible arteries, so the ABI is uninterpretable. Use a toe-brachial index.
- Duplex ultrasound combines B-mode images with Doppler velocities. It's the first imaging test for leg arteries, carotids, renal arteries and veins.
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Sources
- Mazzolai L, Teixido-Tura G, Lanzi S et al. 2024 ESC Guidelines for the management of peripheral arterial and aortic diseases. Eur Heart J 2024;45:3538-700European Society of Cardiology, 2024
- Gornik HL, Aronow HD, Goodney PP et al. 2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease. Circulation 2024;149:e1313-e1410American College of Cardiology and American Heart Association, 2024
- Australian and New Zealand Living Clinical Guidelines for Stroke Management (carotid investigation and revascularisation)AU/NZStroke Foundation (Australia), living guideline, accessed November 2026
- Naylor R, Rantner B, Ancetti S et al. European Society for Vascular Surgery (ESVS) 2023 Clinical Practice Guidelines on the Management of Atherosclerotic Carotid and Vertebral Artery Disease. Eur J Vasc Endovasc Surg 2023;65:7-111European Society for Vascular Surgery, 2023
- Grant EG, Benson CB, Moneta GL et al. Carotid artery stenosis: grayscale and Doppler ultrasound diagnosis. Society of Radiologists in Ultrasound consensus conference. Radiology 2003;229:340-6Society of Radiologists in Ultrasound, 2003
- Ankle Brachial Index Collaboration. Ankle brachial index combined with Framingham risk score to predict cardiovascular events and mortality. JAMA 2008;300:197-208JAMA, 2008
- Xu D, Li J, Zou L et al. Sensitivity and specificity of the ankle-brachial index to diagnose peripheral artery disease: a structured review. Vasc Med 2010;15(5):361-9Vascular Medicine, 2010
- Gornik HL, Rundek T, Gardener H et al. Optimization of duplex velocity criteria for diagnosis of internal carotid artery (ICA) stenosis: a report of the Intersocietal Accreditation Commission (IAC) Vascular Testing Division Carotid Diagnostic Criteria Committee. Vasc Med 2021;26(5):515-25Vascular Medicine, 2021
- Last updated
- 14 November 2026
What changed
- 14 November 2026 Personal emails, About story and Australian-style copy