What Tests Diagnose Peripheral Vascular Disease?
The classic symptom of leg pain on walking that stops with rest is a good indication of peripheral vascular disease. However, only about 40% of people with peripheral vascular disease have intermittent claudication. Upon hearing the patient's symptoms, the health-care professional will formulate a list of possibilities.
- Several other conditions may be suspected.
- The patient's risk factors for peripheral vascular disease.
- The absence of a pulse in the legs or the arms will immediately result in a workup to rule out peripheral vascular disease.
The American College of Cardiology and the American Heart Association guidelines recommend screening for peripheral artery disease (PAD) using the ankle-brachial index (ABI) in patients at increased risk, including adults 65 years and older, adults 50 years and older with a history of smoking or diabetes, and adults of any age with leg symptoms on exertion or wounds that do not heal.
Tests for peripheral vascular disease
Rose criteria: A test used by many medical professionals to screen for peripheral vascular disease is a series of 9 questions called the Rose criteria. The answers to these questions indicate whether you have peripheral vascular disease and how severe it is.
Ankle/brachial index: One of the most widely used tests for a person who has symptoms suggesting intermittent claudication is the Ankle/Brachial Index (ABI).
- This test compares the blood pressure in the arm (brachial) with the blood pressure in the legs.
- In a person with healthy blood vessels, the pressure should be higher in the legs than in the arms.
- The blood pressure is taken in both arms in the usual way. It is then taken at both ankles.
- The pressure at each ankle is divided by the higher of the 2 pressures from the arms.
- An ABI above 0.90 is normal; 0.70-0.90 indicates mild peripheral vascular disease; 0.50-0.70 indicates moderate disease; and less than 0.50 indicates severe peripheral vascular disease.
Treadmill exercise test: If necessary, the ABI will be followed by a treadmill exercise test.
- Blood pressures in your arms and legs will be taken before and after exercise (walking on a treadmill, usually until you have symptoms).
- A significant drop in leg blood pressures and ABIs after exercise suggests peripheral vascular disease.
- Alternative tests are available if you are unable to walk on a treadmill.
- If the leg pulses are not palpable, the use of a portable Doppler flow probe will quickly reveal the absence or presence of an arterial flow.
Imaging tests for peripheral vascular disease
To help locate blockages in your blood vessels, any of several tests, such as angiography, ultrasonography, or MRI (magnetic resonance imaging), can be used. Angiography, or arteriography, is a type of X-ray.
- An X-ray dye is injected into the arteries in question; the dye highlights blockages and narrowing of arteries on an X-ray. This is an invasive study performed in a catheterization or interventional radiology laboratory. The X-ray dye must be excreted by the kidneys. If you have diabetes or already have kidney damage, the dye may precipitate further damage to your kidneys and, rarely, cause acute renal or kidney failure requiring dialysis.
- Some people describe the angiogram (X-ray obtained from angiography) as a "road map" of the arteries.
- Angiography has for many years been considered the best test available and has been used to guide further treatment and surgery.
- Certain treatments for blocked arteries can be performed at the same time, such as angioplasty. A specialist called an interventional radiologist or an invasive cardiologist can perform these treatments.
- Imaging techniques, such as ultrasonography and MRI, are preferred more and more because they are less invasive and work just as well. With either of these two techniques, angioplasty cannot be done.
Ultrasonography uses sound waves to find abnormalities.
- A handheld device that emits ultrasound waves is placed on the skin over the part of the body being tested. It is noninvasive and painless.
- You cannot hear or see the waves; they "bounce" off structures under your skin and give an accurate picture. Any abnormalities in the vessels or obstruction of blood flow can be seen.
- This safe technique is the same method used to look at a fetus in pregnancy.
MRI is a type of X-ray. Rather than radiation, MRI uses a magnetic field to obtain an image of internal structures. It gives a very accurate and detailed image of blood vessels. This technique is also noninvasive.
Several other tests are used under certain circumstances. Your health-care professional can explain why he or she recommends that certain tests be performed.