Q. Lots of small animal vets who new to ultrasound usually asks you if a scanner has Doppler. So, what is Doppler?
A. Doppler helps us to measure movement in the animal such as blood flow. The Doppler Effect is one of the physical characteristics of the behavior of ultrasound waves. If a wave strikes a moving object, the resultant echo is of a different frequency. If a wave strikes a steady object, the wave comes back at the same frequency. This is called Doppler shift and it can be expressed as color by an ultrasound machine.
Q. So what should you use Doppler for?
Doppler can help to provide you with more information for abdominal scanning and cardiac scanning, with the main perceived use in cardiac scanning. You can effectively visualize if fluid is static or moving and the direction in which it is moving.
Fluid when seen under ultrasound is black, so you cannot see if it is moving using regular or B Mode ultrasound. With the use of Doppler, you can see if there is any movement or not. It can also be used while doing biopsies to check that there are no veins or arteries nearby the site of the biopsy.
C. As a small animal vet new to ultrasound, do I need to ask for Doppler as an option on a new ultrasound machine?
Whether you need Doppler on your scanner or not, it completely depends on the type of work you will be doing. We usually find small animal vets who new to ultrasound, concentrating on pregnancy detection and abdominal scanning. Whilst you can use Doppler for abdominal scanning, it is very rare to use this at beginner or intermediate level. It is certainly not the most essential tool for abdominal scanning.
D. Do you really need Doppler in an ultrasound scanner?
For a small animal vet who is new to ultrasound probably will not need Doppler. For pregnancy and abdominal scanning - surely not and you will be very surprised at just how much cardiac scanning you can do without the use of Doppler. Once you become proficient and confident with your cardiac scanning, that is when you may think of adding Doppler to your list of requirements.