Telling if a sow is pregnant or not can be more difficult than people think. In some pigs, unless you are confident with palpation, you will only know for sure when the teats drop. This in itself only happens within 48 hours of giving birth.
On larger farms where pigs may not be so used to handling, it can often be difficult for farmers or veterinarians to touch the animals and perform thorough pregnancy checks. Ultrasound is a fantastic tool for confirming pregnancy in pigs, but setting up the equipment beside a sow and scanning along her flank is not always the safest course of action.
The most fundamental type of frame averaging is “persistence.” This is an adjustable setting present on almost all ultrasound machines, with the exception of some of the current palm-held machines and wireless ultrasound probes, designed as screening tools rather than as full diagnostic ultrasound machines (to view part of my dissertation on handheld ultrasound as a screening tool, visit: pocket echocardiography).
Increasing persistence tends to result in a smoother image, but one which will appear delayed or ‘laggy’ with rapid movement of the target such as a kicking foetus or a heartbeat, or even the panting of a dog or the movement of the operator’s hand. Decreasing persistence results in a much more responsive image, but one which will also appear more ‘grainy.’
Frame averaging can create a more aesthetically pleasing image and reduce the appearance of speckle. The logic behind this being that whether speckle is prominent or not is a matter of wavefront timing rather than the inherent properties of one area of tissue versus the next. Speckle reduction can also make the image more diagnostic by improving contrast resolution. As a post-processing technology, however, it’s not doing anything to discern true reflectors from artefact.
A more advanced method of speckle reduction is spatial compounding. This involves sending separate ultrasound beams from different angles, and then averaging these, rather than simply averaging the same repeated beam from the same angle. This way, if a structure is truly artefactual, it won’t be visible from multiple different angles. Summing of these different returning beams by the ultrasound machine results in an ‘averaging out’ of speckle and an overall reduction in artefact. Like persistence, however, there is a trade-off in terms of frame rate and responsiveness.
Ultrasound is highly technical, and don’t let anyone persuade you otherwise – particularly not those trying to sell you their quick fix solution!
There is no true ‘plug and play’ ultrasound machine. Without an understanding of basic ultrasound physics, technology and the anatomy you are scanning, you are setting yourself up for personal, or even professional failure.
Buy from a specialist
Don’t buy from a Chinese eBay store that sells ultrasound scanners, fitness bands and Halloween costumes. Don’t buy because you’re on a microchip company’s mailing list. If you are going to do well as a pet scanner, get serious, ignore the gimmicks, and invest in yourself. Give yourself the best possible chance of success. Learn from the experts, buy from the specialists, and you won’t end up throwing hundreds or even thousands of pounds away on something that ultimately ends in frustration and failure. This is not only a huge waste of your time and money, but if you try and offer a scanning service to others, you could irrevocably damage your reputation.
If you need help choosing the right machine for you and your business, please get in touch here.
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How to choose an ultrasound machine – if you’re not a professional veterinarian, doctor or sonographer
Choosing your first ultrasound machine can be overwhelming. When thinking about purchasing an ultrasound machine, it’s vitally important that you buy from a reputable source.
A message from founder, Catherine Stowell
I’ve worked with ultrasound now for almost a decade. I was first introduced to the technology when working for a remarketing firm in St Louis, Missouri (USA). I was allocated a portfolio of medical equipment, and my job was to work out what it all did, what worked and what didn’t, and who might want to buy it.
I met so many experienced and talented people from across the United States – from ultrasound engineers to medical doctors – who were happy to teach me about the technology and talk me through quality testing and troubleshooting.
I returned back to London in 2009, and with the support of a contact I’d made in Seattle, began sourcing Sonoscape and Kai Xin ultrasound equipment for veterinary use in the UK (under the name of ‘R C Ultrasound Ltd’). I was also able to supply difficult-to-source transducers through my international contacts in larger markets, such as old Esaote model probes, for practices that would otherwise have had to replace an entire machine.