Venous Duplex Ultrasound 

Venous duplex ultrasound can reveal blood clots by utilizing sound waves to generate images of blood flowing through veins. 

Venous duplex ultrasound is an imaging technique that utilizes high-frequency sound waves (ultrasound) to create pictures of veins that return blood to the heart. During a lower extremity venous duplex scan, the veins in the legs and ankles are examined. A venous duplex ultrasound exam has two parts—two-dimensional echo and Doppler—that are completed simultaneously. The 2-D echo component creates images of the veins being examined. The Doppler component produces audible sounds that can help a physician evaluate the speed and direction of the blood flowing through the veins. 

Conditions Diagnosed 

A physician may order a venous duplex ultrasound test to investigate a suspected blood clot in a leg. This test may be appropriate for a patient who is experiencing: 

  • Leg pain, heaviness or swelling 
  • Leg skin discoloration 
  • Varicose veins 

Procedure Details 

No special preparation is needed for a venous duplex ultrasound exam. Throughout the test, the patient lies comfortably on an examination table. To enhance the quality of the resulting images, a technician will apply a colorless gel to the area of the patient’s body being examined. The technician will then lightly glide a handheld transducer back and forth over the gel. The transducer will emit sound waves that bounce off the underlying tissues and moving blood cells. The transducer will recapture the echoed sound waves and translate them into images, which will be displayed on a nearby computer screen. 

The patient may experience mild pressure as the technician examines each vein. The entire testing process takes approximately 45-60 minutes to complete. 

What to Expect 

Venous duplex ultrasound is a safe and relatively simple diagnostic test that does not involve the use of radiation or dye. There are no known side effects or risks associated with exposure to ultrasound. 


A venous duplex ultrasound scan can provide a physician with valuable information about blood flow and possible blood clots in a patient’s lower extremities.  

Tampa General Hospital’s Heart & Vascular Institute is committed to the early detection of vascular disease using the latest diagnostic technologies, including venous duplex ultrasound.