Ankle-Brachial Index (Arterial Doppler / Segmental Pressures) and Arterial Duplex

Your interventional radiologist may recommend an Ankle Brachial Index to check your risk of peripheral arterial disease (PAD) particularly if you have risk factors that predispose you or symptoms that suggest the disease.  People who have PAD are at greater risk for heart attack, stroke, limb problems and uncommonly, amputation.  While peripheral arterial disease can affect almost any vessel in the body, the limbs are often a simple and easy way to screen for it.

The screening exam is known as an Ankle Brachial Index (ABI) test.  The exam can have several components.

The first component involves taking pressures in each arm and at the ankles or additional levels of your legs. The two pressures are then compared to create a ratio.  This simply tells you if the blood is able to flow to your legs with the same degree of pressure as it is to your arms.  The lower the ratio, the higher the likelihood of peripheral arterial disease.  These pressures are obtained at various portions of your leg.

The second component of the exam involves placement of inflatable cuffs which measure the volume or amount of blood flowing in each portion of your limb.  This gives additional information about how blood is flowing in different portions of your limb and allows your interventional radiologist to determine if you have a blockage in a specific segment based on the amount of flowing blood detected in that segment.

The third component of this exam is the Doppler. Doppler signal is a way of using sound waves to evaluate the way the blood is flowing in an artery.  Narrowing of the blood vessel reduces the flow and changes the signal received by the machine. This is another indirect way to detect the presence of narrowing.

Arterial Ultrasound/Duplex:

If there is an abnormality suspected on your Ankle-Brachial Index (ABI), or the results are felt to not be accurate, your interventional radiologist may get an additional exam known as an Arterial Duplex or arterial ultrasound.  This is a simple, non-invasive exam that uses an ultrasound to look at the blood vessels in your belly through your legs, up to the foot.  You will lay on the table face up, and the leg in question, or both legs, and in some cases the belly will be imaged using an ultrasound machine.  A small amount of warm gel is utilized over the areas to be imaged, and an ultrasound probe is passed over the areas of interest.

The arterial or vascular ultrasound allows you to look at each blood vessel in question and see if there is a narrowing or blockage of the blood vessel.  It allows you to see how the blood is actually flowing through the blood vessels.  If there is narrowing, it allows you to visualize the cause for it—whether it is plaque, or some other vessel problem.  These exams are very important particularly if a procedure is being planned to relieve the narrowing if you have symptoms from peripheral arterial disease, such as difficulty walking, pain or wounds. In uncommon cases, your interventional radiologist may obtain a CT scan as well to evaluate the blood vessels in case the ultrasound offers incomplete information.  The Arterial Duplex can help identify causes of resting leg pain, foot ulcers, pain when walking and/or skin discoloration.

Why choose Fairfax Vascular Center?

Ankle-brachial index is a relatively simple exam, however there are specific technical portions that have to be addressed in order to make the exam results accurate and useful to help your clinical outcome.  Furthermore, if an arterial duplex (arterial ultrasound) is to be pursued, the technical expertise of the ultrasound technologist, the machine quality as well as the interpreting physician all make a difference in the accuracy and utility of the exam and its results.  This can have significant impact on the treatment options that may be presented to you.

Fairfax Vascular Center specializes in performing non-invasive testing such as ankle-brachial index, as well as arterial ultrasounds with some of the longest standing experience in imaging and assessment of peripheral arterial disease in the region. Our interventional radiologists are seasoned vascular and imaging specialists routinely assessing patients with peripheral arterial disease in clinic, conducting and interpreting their imaging, as well as providing treatment of peripheral arterial disease including minimally invasive procedures such as angioplasty, angiography, and atherectomy.

Thanks to our rigorous emphasis on quality of imaging, interpretation and clinical follow-up, we are able to provide our patients with the utmost in experience and care.

Have a discussion with your physician or interventional radiologist to determine if an Ankle-Brachial Index or arterial ultrasound is an appropriate addition to your Peripheral Arterial Disease workup.