Key Points about Lower Extremity Ultrasound

  • A lower extremity ultrasound is a test used to diagnose deep vein thrombosis (DVT)
  • Your doctor will order a lower extremity ultrasound to search for blood clots in the legs
  • During the test, your doctor will take images of your vessels using a small instrument called a transducer
  • A lower extremity ultrasound takes 30 to 45 minutes to complete. The exam is generally pain-free and easily tolerated

Overview

A lower extremity ultrasound is a diagnostic imaging test used to evaluate the blood flow through the legs’ major veins.

A Doppler ultrasound will measure your blood flow and blood pressure by bouncing high-frequency sound waves off the red blood cells circulating in the legs.

If you are at risk or experiencing deep vein thrombosis symptoms, your doctor will order a lower extremity ultrasound to search for blood clots.

Candidates for a lower extremity ultrasound

Your doctor may order a lower extremity ultrasound to search for blood clots in the legs. Blood clots can break off and travel to the pulmonary arteries causing a pulmonary embolism.

Preparing for a lower extremity ultrasound

In preparation for a lower extremity ultrasound, follow your doctor's pre-imaging instructions. It is also important to wear comfortable clothing and bring your doctor's order to the exam.

Expectations during a lower extremity ultrasound

You will be instructed to undress and lie on your back on a padded exam table. Your technician will spread warm gel on your legs and move a small handheld unit called a transducer over the skin. Images of your blood vessels will be portrayed on the video monitor. You will be asked to lie still during the ultrasound.

The Doppler ultrasound can measure the speed of blood cells as they travel through the blood vessels. The blood cells cause a change in the pitch of the reflected sound waves as they move through the vessels. A computer will create graphs that represent the blood flow through the vessels.

Duration of a lower extremity ultrasound

A lower extremity ultrasound takes approximately 30 to 45 minutes to complete. You should be able to return to your normal routine after the test.

A radiologist will review your results and send a report to your physician within one to two days. If a follow-up exam is necessary, your doctor will contact you to schedule that visit.