What color can and can’t do on the ImagePad:
What the ImagePad Color can do:
- Rule blood flow in/out, as discussed above – in sick patients, blood perfusion may be poor in certain areas of the body, e.g. the extremities, or areas suffering from ischemia (lack of blood supply) after an event like a stroke. The vet can confirm whether there is blood flow in the region under examination with Color Doppler.
- Help to distinguish between a cyst and a vessel – a vet should have the knowledge and dexterity to do this through probe manipulation, but many don’t!
- Help to distinguish between an artery and a vein by looking to see if blood flow is pulsatile or not. The color itself will not tell you whether flow is venous or arterial (remember that the color is only the direction of blood flow in relation to the position of the transducer, not the direction of blood flow towards or away from the heart), but arterial blood will be pulsatile and higher velocity.
- See if a tumor has blood flow or not. This will help the vet to diagnose what type of tumor it may be, and how easily it can be treated. Knowing how vascularized it is can also inform the surgical approach taken.
- Help in the acute/emergency setting, e.g. why is there a pericardial effusion? Is it due to trauma? Is there communication between the heart and the sac that surrounds it, the pericardium? If there is flow between the two, color will show this. An acute effusion due to injury is an emergency situation; a chronic effusion due to infection is not. Both can look the same on 2D imaging.
Color Doppler on the ImagePad is basic. Main limitations:
- It lacks the sensitivity to pick out very low flow, tiny vessels, such as the intricate vasculature inside the kidneys (though it will pick up the main branches). This is normal. In fact, a more sensitive Doppler mode called Power Doppler is often used for kidney imaging, because this can be a problem even in very expensive Doppler systems.
- It is not suitable for serious cardiac work as it lacks the frame rate to catch regurgitation at fast heart rates. It simply cannot sample fast enough to accurately show us what is going on with blood flow. Decreasing the size of the color box will help, but will not solve this problem. Only a $25,000+ machine will!
What type of probe do I need with my ultrasound machine?
Your probe (or transducer) is the most important part of your ultrasound system, so it’s important that you understand the differences before you choose what to buy. Our most popular choices available on the Scan Pad, in order of popularity:
- Microconvex: Small footprint, with a frequency range of 3.5-7MHz, this probe covers almost all small animal applications. It’s ideal for pregnancy scanning dogs, cats, and even small goats.
- Convex: With a larger scanning surface than the microconvex, some dog breeders prefer that they can cover a larger area in a single sweep. However, the lower frequency range (2.5-5MHz) means that images with the large convex probe will not be as high resolution as the microconvex can achieve. For larger animals, such as giant breed dogs or large breed goats or pigs, the convex transducer is the ideal choice as the lower frequencies can penetrate more deeply.
- Linear Probe: The linear probe offers a very high-frequency range of 6-9MHz. It’s the best choice for scanning close to the surface, such as tendon scanning, or abdominal scanning on slim dogs, cats, and scanning for eggs or follicles in reptiles, particularly snakes. The superior image quality achievable with a linear probe is striking, but it’s not a good option for general small animal pregnancy scanning and does not provide a sector image.
- Linear Rectal Probe: Also high frequency (6-9MHz), this probe is for rectal examinations in cows and horses.
All Scan Pad transducers are at the top end of the entry-level market, with 80 ceramic elements. Most equivalent systems from other manufacturers use 64 elements.