Ultrasound Scan: Colour Doppler, Duplex, and Triplex Doppler. What do they mean?
You are having an ultrasound scan or your doctor recommended a colour Doppler, duplex or triplex scan. It is normal to get confused as these are not terms that you use every day. On this post, we will try to demystify some of the terms related to ultrasound scanning.
Ultrasound was discovered in 1880 by Jacques and Pierre Curie and its first application were to detect submarines in 1917. In 1956, a team led by Obstetrician Ian Donald and engineer Tom Brown developed the first ultrasound machine to be used in clinical practice. As you can imagine the first applications of ultrasound were primarily in baby scanning. By the end of the 20th century, ultrasound scans were extensively used in maternity clinics.
Initially, the ultrasound images used to be black and white – and still are. These images are called 2D images as being two-dimensional.
Colour Doppler or colour flow Doppler, that was discovered by Christian Doppler in 1841, is the technology to visualize blood flow during an ultrasound scan. Colour flow is being used all the time these days as it helps to differentiate between different structures, for example, a blood vessel and a cyst that can have a similar appearance on ultrasound. It helps to evaluate the vascularity of a tumour found for example in the breast scan, pelvic scan or liver scan. It helps to evaluate the vascularity of whole organs such as in the thyroid scan in cases of thyroiditis.
When the colour Doppler image is combined with the 2-D greyscale image is called duplex Doppler.
Triplex Doppler is a combination of the Doppler, 2D image and spectral or pulse wave Doppler. The spectral Doppler helps to evaluate the velocity of blood flow. It is commonly used in arterial studies such as deep vein thrombosis scans you to exclude a thrombus in a vein or in the carotid artery ultrasound scans.
We hope this article helped you to understand what these terms mean.
In our London ultrasound clinic, we use the latest ultrasonic equipment which is capable of colour Doppler, duplex and triplex imaging so that we can confidently identify structures during your Private Ultrasound scan. To find out more about the reasons you might choose a to have a private ultrasound scan instead of waiting weeks for an NHS ultrasound scan see our 'Why to have a Private Scan' blog.