Hello again! Leanne here from ScanX, recently we’ve spoken about depth, gain and frequency and different modes used. Today we look at transducers, what they are and which ones you would need, based on what your using a ultrasound machine for.
Also known as the “probe” the transducer is what you will use to transmit and receive the ultrasound waves, which your machine will show as your image. The transducer generates ultrasound waves using the piezoelectric crystals within, which will penetrate through the body and return to the probe, when returned to the probe the energy obtained is translated to an electrical current to be sent to the machine to allow processing and eventual display, this process is very quick meaning the images you are seeing are in real time.
There’s more than one type of transducer
Each transducer has been developed to be good at its particular task, so this is why it’s so important to make sure you have the right one for your needs, if after reading this blog you are still not sure, we are always happy to chat and help you.
During this blog I will summarize the 4 types of transducers, focusing on size, shape and the frequency at which ultrasound waves are emitted.
These probes are most suitable for small, large, and exotic animal ultrasound.
The frequency (that is, how many waves are emitted per second) matters because it directly affects what we can see and how clear the image is. At lower frequencies whilst we are able to penetrate further into the animal to see what we need; the image quality reduces. Whereas at higher frequencies we are not able to penetrate as far into the animal, but due to the higher frequency the quality of the image is much higher.
MHz means how many million waves per second it can send depending on your systems settings.
The footprint of the probe is relatively large, or the area that makes contact with the skin. A convex probe is more of use for giant breed dogs, large animals such as sheep, goats, pigs, and cows. A convex probe has a lower frequency of between 2.5-5MHz. This for larger animal’s results in better penetration, but unfortunately the tradeoff is a lower resolution.
If only scanning small animals this maybe the only probe you’ll ever need!
The head of a Microconvex probe is smaller than its larger relative of the convex probe. It operates at a higher frequency, which means its penetration is reduced, this means that it is less suited for large animals. Although it cannot penetrate so far it does have its own advantages, it has a higher frequency at 3.5-7MHz which means it offers higher resolution images. As a smaller probe it offers more maneuverability.
Linear probes are good for providing good quality images when scanning close to the surface. With a particularly high frequency 6-9MHz. These probes can be applied to scanning tendons, abdominal scanning of small or slim cats and dogs along with the scanning of reptiles when looking for eggs or follicles.
We would not recommend that this probe Is used for general use in small animals.
A variation on the linear probe is the linear rectal probe developed for internal scanning of larger animals (for example cows and horses). It shares the linear probe’s high frequency and high image quality close to the surface to which it is applied.
Choosing the right transducer
The right transducer for you will depend on how you plan to use it. It will also be important to consider your budget and any existing equipment you have. You will find that many new ultrasound machines are packaged with a transducer, but equally common is that you will need to specify the transducer you require (if any) at time of purchase.
At ScanX we offer both options for maximum flexibility. In addition we are delighted to offer great value packages for those just starting out on their ultrasound journey as well as new machines tailored for use with particular animals (whether you are a breeder, vet, work on-farm or with reptiles/exotics).
If you are in any doubt at all please don’t hesitate to contact our friendly team who will be more than happy to provide advice and information to help you make your choice.
What have we learnt?
• Transducers – also known as ‘probes’ – are the device you will use to transmit and receive the ultrasound waves which will in turn be translated into an image by your machine.
• Key differences between transduces tend to relate to their size, shape and the frequencies at which they emit ultrasonic waves.
• Convex probes scan at lower frequencies, are larger, and well suited to larger animals.
• Microconvex probes scan at medium/high frequencies, are smaller and are ideal for most small animal applications.
• Linear probes are specifically adapted for applications close to the surface, with particularly high frequencies. They are particularly commonly used when scanning for eggs or follicles in reptiles, or for the scanning of tendons in other animals.
• Linear (rectal) probes also scan at a high frequency and are designed for internal use with cows and horses.
• Key factors to consider when purchasing include your planned use, budget and any existing equipment you might have.