CT for horses - image quality and safety are crucial

Like humans, when horses are scared, they tend to ‘fight or flight’. That is, either lashing out or doing whatever they can to escape from what’s scaring them. The outcome of either is potentially extremely dangerous for anyone near the animal, but it can also put the horse’s safety at risk. For equine veterinarians Dr Andre Böhmer and Dr Thorben Schulze, creating a safe and calm environment for all is just as important as any subsequent examination – because, simply put, one cannot happen without the other. “If a horse is in an unfamiliar environment, it must feel it can escape from a frightening situation in a fraction of a second,” Dr Thorben explains. 

An equine veterinary specialist, Dr Böhmer has worked for the Telgte veterinary clinic since 2002. His practice has recently crossed paths with Dr Schulze (who is both an equine and diagnostic imaging specialist) when the clinic installed a new Canon CT scanner on a height adjustable platform. Called the 'Qalibra-CT', the solution was developed by Dr Schulze together with specialist veterinary diagnostic imaging consultants Vet-DICon GmbH and cleverly incorporates a lifting platform so that scans can be performed on many different anatomical regions of the horse while it is still, non-anaesthetised and – crucially – calm). It’s a new and innovative way to ensure maximum safety for all involved.

“We wanted to facilitate the CT examinations in such a way that the horse does not have to be in a restrictive examination stand,” explains Dr Schulze, who adds, “We wanted to find a new way for equine veterinarians to carry out examinations, safely and quickly, without compromising image quality. Until now, this has mostly been reserved for human medicine.” To achieve this, he and Vet-DICon spent years working with a team that includes technicians from Canon Medical, mechanical engineers, radiation protection experts and innovative veterinarians to create a solution that hits the mark. 

There are many scenarios that might require a horse to undergo a CT scan, but it is primarily used for the head and limbs ­– especially joints – and this new CT scanner opens even further possibilities. “We can perform examinations of the front and rear limbs, head and neck of the standing horse,” explains Dr Böhmer. “In addition, under general anaesthesia, we can visualise upper limbs, from the stifle to the hips, the thoracic spine, and occasionally even the sacral joint and the back.” However, the fact that the Qalibra-CT allows the animals to stand while being examined reduces the need for general anaesthetic, which is obviously an excellent benefit to both horse and veterinarian, as it lowers both risk and cost.

The adjustable platform is obviously a real boon to the process, but Canon Medical's Aquilion Large Bore CT also solves some other tricky problems that are particular to examining horses. “With a gantry opening of 90 cm, it has the world’s largest field-of view of up to 85 cm, so we can examine our rather large patients more easily,” says Dr Böhmer. “And the high image resolution of the system, in all three-dimensional planes, was a key feature for us. Even structures as small as 0.31mm can be displayed.” Being able to scan the animal, then reconstruct the images in extremely high quality is especially important for horses, as aligning them completely straight in the scanner can prove impossible. “The height-adjustable patient couch works regardless of if the horse is standing or laying down, making it easier for the horse and veterinarian,” adds Dr Schulze. “The result is that head, neck and even limb regions can now be examined more quickly by CT than previously possible with X-Ray. Even a complete examination of both stifle joints, which requires general anaesthesia of the horse, often takes less than 10 minutes.”

The Qalibra-CT is still relatively new and only in use at a few veterinary centres around the world, but examples of the Qalibra-CT in action can be found on YouTube: ‘New Opportunities for Equine CT Under General Anesthesia’, ‘Standing CT for the Equine Head and Neck’ and ‘Standing CT of the Equine Distal Limb’. And, of course, Dr Schulze is pleased that equine clinics are already having plenty of positive new experiences. “Especially with examinations of the thoracic spine, the fetlock and the stifle joints” he reports. “We are looking forward to the first scientific publications resulting from this work.” 

This article is kindly abstracted from Canon Medical Systems Europe VISIONS magazine #36. 

Pictured top: Height-Adjustable, Sliding Gantry CT System. First installations in Belgium, Germany and Switzerland. Photo: Bosdreef Referral Hospital for Horses.