Summary The resistance index is quick and easy to calculate on ultrasound machines with PW Doppler capability. Obtaining useful readings from the umbilical artery in dogs takes a lot of practice, and should be obtained from the mid-cord to ensure reproducibility. The resistance index will fall 12 hours prior to delivery, falling further 1-6 hours before, so can be used to predict when labour should begin. If the resistance index falls but labour does not follow, this can alert the breeder or vet to the possible need for veterinary intervention. M-mode can......
How early can I scan a rabbit? Positive confirmation of pregnancy has been documented as early as 7 days in rabbits, but only by the presence of fluid inside the uterus, which is a sensitive but not specific sign of pregnancy: in other words, you’ll always see it in a pregnant rabbit, but you could also see it in a rabbit coming in or out of season, or when something is wrong. It is also worth noting that in such studies, rabbits were completely shaved and mechanically restrained on their backs. While......
A video walk through of some of the most important controls on the ScanPad and ScanPad+ ultrasound machines. If you want to understand more about these controls, along with example images from canine pregnancies, you can get your copy of Ultrasound for Canine Pregnancy Scanning here. You may also find the Scan Pad QuickStart Guide very useful. Gain and depth Your two most important controls! Frequency Some ultrasound machines display frequency in MHz, and others will display three settings – Pen, Gen, and Res. Focal Zone The focal zone......
Ultrasound is not (yet) an exact science. Machine learning is helping to bring us closer to it, but even when this day comes – and it’s currently only in the research stages – it’s unlikely that the human component will ever be completely replaced in our lifetimes. There will always be exceptions to rules, and at the moment, only a human brain is capable of thinking around these instances. Because ultrasound can be so subjective, it’s important that you are part of a supportive community that you can turn to when you......
Tissue Harmonic Imaging is a relatively recent discovery that greatly improves image quality, primarily due to a great reduction in the amount of ultrasound artifacts (see Chapter 14 of Ultrasound for Canine Pregnancy Scanning). Put simply, it involves sending out ultrasound at one frequency, but only using higher returning frequencies (that we didn’t used to know were even generated!) to generate the image. These higher frequencies are created as the ultrasound waves pass through tissue, so are particularly helpful when scanning larger animals – less helpful when scanning shallow structures that are......
Dogs and cats with significant mitral regurgitation (MR) may show pulmonary venous flow reversal. Flow reversal is a supporting measure only, and not specific enough to be used as a standalone method of grading MR severity. Normal pulmonary vein flow pattern The normal flow pattern of the pulmonary veins shows two forward-flowing waves – systolic (S) and diastolic (D). The S wave should be of equal or greater velocity than the D wave. There is also a small reversal wave (Ar) that occurs at the time of atrial contraction. This is present even......
An increasing number of AUA members are turning to scanners with Doppler capability as their next ultrasound machine. Primarily, this is due to the higher resolution images they tend to produce (colour Doppler systems use higher spec graphics cards and other components, so even if you never use your colour, you still benefit from improvements in performance), but there are ways you can put your Colour Doppler to good use. Remember that Doppler imparts higher levels of ultrasonic energy, and should be used sparingly over the foetus itself. Obstetric sonographer......
Below is a tour from Yvette Lovis around the foetal anatomy. Taken at the canine pregnancy scanning course run in Edinburgh last month, identifying: – Foetal heart – Foetal stomach – Foetal liver – Foetal bladder – Chord insertion – Spine – Head and neck Yvette also delivers a walk-through on measuring BPD, available to AUA members. Simply sign into your account and view her video here. With thanks to Kilnhurst Collies...
Screening for hypertrophic cardiomyopathy (HCM) can currently only be performed by a veterinarian. Yet, with increasing numbers of breeders becoming proficient in the use of reproductive ultrasound, there is a growing interest in expanding their skills to heart scanning. In the world of pregnancy scanning, a number of trained and experienced scanners work closely with their veterinarians. Some scan inside their local practice, and others scan independently, receiving referrals from their veterinarians and referring any concerning cases back in return. Most vets simply don’t have the time for performing detailed pregnancy scans......
As the New Year dawns, it’s common for people to get in touch about 2019 training courses for animal ultrasound scanning. Given that January is typically a time for making new commitments and investing in one’s self, this is hardly surprising. Ultrasound scanning to detect pregnancy in dogs is becoming increasingly mainstream, and whilst many people do appreciate the time and study that goes into it, one unfortunate byproduct of its increasing popularisation is the impression that it’s something that can be mastered after a single day’s training and a relatively low......