Duplex Ultrasound
Duplex Ultrasound has revolutionised the way that healthcare professionals treat varicose veins and related conditions such as phlebitis, varicose eczema and leg ulcers.
At the VeinCare Centre, we use duplex ultrasound as part of the initial consultation, on the day of the vein procedure and during follow up appointments.
The ultrasound equipment builds up a picture of the structures of the blood vessels, as well as superimposing the flow of blood and its direction so that we can tell whether there are problems with veins. These may include blockages, problems with the valves, or blood flow in the wrong direction known as ‘reflux’.
When you visit for your scan, the whole leg will be scanned from the top of the thigh down towards your ankle, even if the vein problems seem to be confined to one area. A water-based gel is used to allow the sound waves into the leg so that a picture of the vein and the blood flow in it can be built up. In the video above you can see how Duplex Ultrasound is used to detect the root cause of your leg vein problem.
A Duplex Ultrasound examination is provided as part of a consultation.
What is Duplex Ultrasound?
Duplex ultrasound involves using high frequency sound waves to look at the speed and direction of blood flow and the structure of the leg veins. The term “duplex” refers to the fact that two modes of ultrasound are used, Doppler and B-mode. The B-mode transducer obtains an image of the vessel being studied. The Doppler probe within the transducer evaluates the velocity and direction of blood flow in the vessel.
Is a Duplex Ultrasound Scan the same as a Doppler Scan?
This is a question we hear a lot. Some people are confused whether a Duplex Ultrasound Scan is the same as a Doppler Scan. Actually, a Duplex Scan is a combination of two scans. A B-mode scan which builds up a picture of the veins and then a colour representation of the Doppler Scan is superimposed on the image of the vein.
A Duplex Ultrasound Scan includes a Doppler Scan as well as a B-mode Scan.
What is a Bilateral Scan?
Bilateral refers to the fact that both legs are scanned. If only one leg is scanned, this is referred to as a Unilateral Scan.
The VeinCare Centre recommends that everyone with leg vein problems has a “Bilateral Duplex Ultrasound Scan” even if it appears that only one leg is affected.
You will need to stand during the examination
For at least part of the examination, you will need to stand. A warmed ultrasound gel will be applied to your leg. It will not cause any allergic reactions or stain your clothes. This gel provides a contact between the ultrasound probe and your leg so that the ultrasound beam can penetrate into your leg.
A nurse will be will be present throughout the examination to check on your well-being.
You will be asked to let the nurse know if you feel uncomfortable or faint at anytime. If you feel giddy, it is important to let the nurse know as soon as possible and you will be asked to lie down for a few minutes.
Risks and side-effects
A small number of people feel faint during the examination. If this happens it can easily be alleviated by lying flat for a for few minutes.
So if you do feel faint, please do not be embarrassed, just let the nurse know as soon as possible.
There are no other known risks associated with having an ultrasound scan of the leg veins.
Why do I need to stand for my scan?
Varicose veins are caused by superficial venous reflux – down flow of blood in the wrong direction in the veins under the pull of gravity. It therefore follows that to accurately diagnose the root cause of varicose veins, gravity must be acting on the veins when the veins are examined.
We hear many stories of patients who have had inadequate treatment because they were scanned with ultrasound while lying down. Identifying the presence of reflux, where it is coming from and which veins are affected, can only be accurately assessed by duplex ultrasound when the patient is standing.
So, even though some people may feel faint and giddy during a vein scan, at least some of the scan should be performed in the standing postion.
Furthermore, to accurately identify the varicose veins for adjunctive procedures such as phlebectomy and foam sclerotherapy, skin marking must be performed while the patient is standing.