Arterial Doppler Ultrasound of the Leg
Sonography is Useful for Diagnosing Peripheral Artery Disease
Aug 24, 2009
Peripheral arterial disease (PAD), also called peripheral vascular disease (PVD), is inadequate blood circulation in the legs, most likely due to plaque buildup in the arteries. Risk factors include hypertension, diabetes, smoking, and obesity. Pain or cramping while walking, called claudication, is a common symptom. More advanced cases of peripheral arterial disease may include signs such as absent pulses in the feet, abnormally-colored skin, shiny skin on the legs and feet, cold legs and feet, thick toenails, and open sores. Ultrasound is used for peripheral arterial disease screening.
Patient Preparation
No special preparation is necessary before the exam, however one will be asked about his or her medical history and should be able to answer the following questions:
- How many city blocks can you walk before the pain starts (this is claudication)?
- Do you have pain, cramping, and numbness?
- Do you have any sores on your legs?
- Are you diabetic?
- Do you have hypertension (high blood pressure)?
- Do you have hypercholesterolemia (high cholesterol)?
- Did you take your blood pressure medication, today?
- Do you take aspirin or any other blood thinners?
The patient will be asked to remove his or her pants and socks and to wear a gown. The patient may sit up for the exam. The leg to be examined will be rotated out and bent at the knee. This allows for easier visualization of the arteries of the thigh and popliteal fossa, the area behind the knee. The leg can be straightened for examination of the arteries of the lower leg.
Sonographic Arterial Study
The leg arteries are thoroughly examined. Three images are taken of each section of artery. A 2D grayscale image is taken to demonstrate any plague buildup. A color Doppler image shows the blood flow within the artery. Pulsed wave Doppler records the velocity of blood traveling through the artery and gives a waveform. The arteries examined are:
- Common iliac artery near the groin
- Superficial, mid, and distal superficial femoral artery of the thigh
- Popliteal artery behind the knee
- Anterior tibial artery of the lower leg
- Posterior tibial artery of the lower leg
- Peroneal artery of the lower leg
- Dorsalis pedis artery of the foot
Ankle-Brachial Index (ABI) - Doppler Ultrasound
The ankle-brachial index is another test used to determine the extent of peripheral arterial disease and is usually done at the time of the ultrasound. Blood pressures are taken in each arm and each ankle. The sonographer may use a handheld Doppler device instead of a traditional stethoscope. The right ankle blood pressure is divided by the right arm blood pressure. The same is done for the left side. If the ABI is less than 1, then vascular disease is present.
Related Articles
MayoClinic.com: Peripheral artery disease (PAD)
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