Doppler Terminology

Throughout this course we have been using the terms Color Doppler, Pulsed Doppler, Continuous Wave Doppler, etc. to refer to the various methods used to detect and display blood flow in ultrasound.  This was done for good reason, because these were the accepted terms that have been used since these technologies were first developed.

However, in 2025, a subcommittee of the AIUM produced a paper (at right) that indicates that these terms have been used incorrectly.  The subcommittee states that only Continuous Wave Doppler detects and uses the Doppler shift, and therefore can be called Continuous Wave Doppler.  

The paper goes on to say that all of the pulsed "Doppler" modalities, such as pulsed wave, color flow, and tissue Doppler, actually only detect phase shifts, and are not actually using the Doppler shifts to detect blood flow.  

Consequently, the subcommittee recommends that we refrain from using the term Doppler to describe any of the pulsed methods for blood flow detection and limit the term Doppler to the use of Continuous Wave.  

As a result, here are the recommended terms:

• PW mode 

• Color Flow mode (for both color and power)

• Continuous Wave Doppler

Of interest, the authors do not specify what we should call Tissue Doppler, but based on the article, we can be assured that the term Doppler is not recommended.

In summary, this is really just a change in nomenclature.  My explanations on all of these modes are still completely valid and useful.  👍

And much as I'd love to change the terminology in this course, I have been using the Doppler terms for over 30 years, so it is simply not feasible at this point to change the nomenclature in all my videos and notes.

My goal here was simply to make you aware that going forward from 2025/2026, it is likely that the AIUM recommended terms will gradually be adopted.  Time will tell.