An Inside View: Equine MRI

The benefits of using MRI in horses.

Diagnosing lameness in horses, which is a common problem, has gotten easier for veterinarians and horse owners through the use of Magnetic Resonance Imaging (MRI) technology. MRI uses a powerful magnet, radio waves, and a computer to create detailed images. Unlike X-rays, which images bony tissue, or ultrasound that is best for viewing soft tissue, MRI can see inside bones and soft tissue. Veterinarians have a more effective way to look inside the hoof capsule, as well as the tendons, ligaments, joint capsules, navicular bone, and more.

The technology continues to improve. When MRI was first used on horses in the late 90s, horses had to be put completely under anesthesia and there was significant risk in recovery. Horses could even break legs as they came out of anesthesia. When a horse is having an MRI for a minor problem, the last thing you want to do is create a major issue during recovery. In addition, it took a lot of manpower to move a horse around on a gurney for a full-body scan.

Twenty years ago, horse owner and MRI physicist, Dr. Nick Bolas, developed a standing MRI machine to provide an affordable, safe, and convenient solution to some of the problems he saw with traditional MRI. In 2001, he founded Hallmarq, a company specializing in advanced veterinary imaging.

“Now, years later, we have more than 100 installations in 25 countries around the world,” said Dr. Dan Brown, BVSc ACIM and chief customer officer and vice president for North America. “Hallmarq is still the only company with a standing MRI option. A lot of our cases, somewhere in the region of about 75% of all our MRI, are horses with foot cases. We can view more than that, but that is where most lameness problems are.”

The caseload for Hallmarq comes from a variety of sites and clients, including one-person equine clinics to large multi-doctor referral clinics.

“We have some machines at racetracks, and universities, but the bread and butter of most of the scans we do are from English disciplines; hunter-jumpers, dressage – that kind of thing,” Brown said. “There is also a clinical application for MRI in the Western disciplines, but historically we haven’t seen it as much because the company started in Europe. It is an area in which we are starting to see increasing growth.”

An affordable option for Equine MRI

Typical MRI machines are very expensive, running close to or in excess of $1 million.

“What we wanted to do was make that technology financially accessible for small businesses, which is essentially what most veterinary clinics are,” Brown said.

Hallmarq offers two options for installation, with the scanner either installed in a room in the clinic or a modular version, which is essentially a plug-and-play room with the MRI and everything you need in it, Brown said.

“The module option has helped us reduce the upfront cost,” he added. “We deliver it, set it up, and train the staff. The delivery installation training and site setup fee are typically less than $40,000, which for a million-plus-dollar piece of equipment is pretty easy. And to put it in perspective, that $30,000 to $40,000 is about the same as you could pay for one digital radiography plate.”

In addition, it is designed so veterinary technicians can use the system. “You don’t have to hire a specific MRI technologist like you would do with the human system, so that keeps the running costs down,” Brown said.

Once installed, the sites pay Hallmarq for the system’s maintenance and for scans.

“The first option is a fixed monthly fee, which covers everything you need to keep the system up and running from routine maintenance visits to spare parts, to on-call support and advice – even upgrades are included,” Brown says. “We also help the site with their marketing so they can make their MRI business a success. Apart from maintenance, they also pay when they use it. This means their billing actually flexes with how busy they are. If they have a really busy month, we bill them more because they’re using it more, but they’re also making more revenue. Conversely, if they have a quiet month, their bill goes down.”

Advantages of MRI

Anatomically, the standing MRI systems cover foot to knee and foot to hock. When a veterinarian sees a lame horse, they’re going to take a history, do a physical examination and probably go to X-rays fairly quickly just to see if there’s anything obvious, like a fracture, said Brown.

“Where MRI fits in is where you’ve done this basic evaluation and you still don’t have an answer,” he said. “If you don’t know what area is causing the pain or what structure is damaged, you can’t treat it. You’re just shooting in the dark. We’ve actually been able to show that what was thought to be – before MRI – a navicular bone problem, was frequently coming from the soft tissue surrounding the bone or potentially if there is a bone component, it is complicated by an additional soft tissue component which also needs treatment.”

Brown said he sees “light-bulb moments” when visiting with veterinarians about MRI.

“They tell me, ‘this is why when I treat two horses that are identical clinically one will get better and the other one won’t, and we have no idea why,’” he said. “It’s because before MRI we never had a way to say, yes, these horses look the same clinically or on X-ray, but in fact, their issues are very different. MRI is showing that one horse also had a split in its flexor tendon, but the other one didn’t. Because it was undetected, it was untreated. Because it was untreated, it didn’t get better and the other horse did. It explains a lot of the frustrations that we’ve had with lameness, particularly soft-tissue lameness in the foot.”

Another positive use of MRI is effectively predicting fractures in racehorses. “We’ve all heard in the news about these racehorses breaking their legs while they run, and that is a repetitive stress injury,” Brown said. “The bone gets increasingly damaged over time until it becomes weak enough that one more training session or race will cause a fracture. It’s not a question of the bone being completely normal then one day the horse goes out and breaks it. The bone is getting weaker or more brittle over time, then one day it breaks. This process of pre-fracture changes gives us something to look for to identify at-risk horses.

“Through MRI, we’ve seen changes such as water within the bone that shouldn’t be there and is a sign the bone is unhappy,” he adds. “The great news is that you don’t need to use expensive treatment. Stop them running fast for a few weeks and that bone will heal itself. So it’s a very good news story if you can get it early and it’s very bad if you don’t.”

Take-home messages

MRI provides both clinical and business advantages for a veterinary practice. “On the clinical care side, obviously the fact that we can now see things and diagnose problems that we couldn’t before is extremely important,” Brown said. “If you can’t diagnose it, you can’t treat it. From a client perspective, a client would much rather know exactly what they’re dealing with, what the prognosis is, and the right treatment plan, rather than shooting in the dark. It’s not a positive message to tell clients, ‘I don’t know what the problem is, so let’s try this and see what happens.’” MRI allows for targeted, science-based treatment.

“This also creates the bridge to the economic side of it, because it enables a veterinarian who wants to recommend some more of the expensive regenerative medicine treatments, to justify them because they know, because of an MRI, that it is exactly the right treatment.”

Hallmarq has a study underway to assess the belief that for every dollar a clinic bills for an MRI and for taking the images, there is at least another dollar of downstream revenue that the diagnosis will generate.

“If you are a practice wanting to build a referral caseload, one way to do that is to offer a service that neighboring clinics can’t, such as MRI.”