What is Venous Ultrasound?
An ultrasound exam uses sound waves to study human tissue, and when applied to the veins, it is a venous ultrasound. It is extremely safe without any radiation or magnetic fields. That’s why ultrasound is used to look at babies during pregnancy. A trained ultrasound technician (also called ultrasonographer) is typically the professional that conducts the exam, but some physicians may also do it themselves during office visits. Just like a baby prenatal exam, a venous ultrasound starts with some acoustic gel and an ultrasound probe on your legs. From there, the technician scans up and down your and may push on you to look for a number of things:
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- The appearance of the vein structures
Ultrasound forms a 2D image of your internal structures so that the veins can be located and studied.
- The appearance of the vein structures
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- Sizes of the veins
Most healthy veins fall in certain size ranges. Very enlarged veins may indicate venous disease.
- Sizes of the veins
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- What is inside of the veins
Most healthy veins should be nice and round. When pushed, the vein collapses as the blood gets displaced. This may be altered if there has been scars, injuries, prior procedures, or clots in the veins.
- What is inside of the veins
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- Blood flow and valve function
Veins flow through a bunch of internal valves against gravity. Your ultrasound technician will study this pattern and determine if there is abnormality with the flow.
- Blood flow and valve function
What is a Venous Duplex Ultrasound Study?
The medical field really loves fancy terms. Depending on the area or healthcare facility you visit, you may seen terms like “Duplex”, “Doppler”, “Ultrasound”, or a combination thereof scheduled for you. In reality, they are quite interchangeable and often mean the same thing.
In broad terms, ultrasound uses 2 core functions to look at veins. Brightness mode, or B-mode, is 2D representation of the internal structures and allows the ultrasonographer to see the veins. From there he or she can see what is inside of the veins and measure their sizes. The second function is the Doppler exam. Doppler study measures the direction and speed of the blood flow. Modern venous ultrasound uses both the B-mode and Doppler mode together to make sense of the body. Just like a duplex apartment, the combination of these 2 ultrasound modes is called “Venous Duplex“.
Two Kinds of Venous Duplex Ultrasound Studies
Not every venous ultrasound is created equal. There are 2 kinds. The first kind is designed to look for blood clots. The second kind is designed to look for vein functions.
Venous Duplex for Blood clots
These may be called just venous ultrasound, venous duplex, or limited venous ultrasound. This is the most common vein ultrasound study and is typically ordered by the emergency room or primary care to rule out dangerous deep vein thrombosis.
Venous Duplex for Venous Function
These may be called venous reflux ultrasound, venous reflux duplex, or comprehensive venous exam. Not only does this study look for dangerous blood clots, they also evaluate the function of the valves. This is the preferred study by vascular surgeons and is the most helpful study for patients with varicose veins.