8 minute read
GOLD STANDARD DIAGNOSTICS
Magnetic Resonance Imaging at Moore Equine
STORY AND PHOTOS BY JENN WEBSTER
The war against equine lower limb lameness has a tough warrior at its advantage in western Canada – Moore Equine in Calgary, Alberta, offers standing equine Magnetic Resonance Imaging (MRI) to the public. Although the technology has been available in British Columbia, Saskatchewan, Ontario and Washington for a while, it’s the first of its kind in the province of Alberta. MRI is a diagnostic technique that uses a magnetic field to produce pictures of structures inside the body. It’s an extremely exciting modality for horse owners because previously in the province of Alberta, diagnosing lower limb lameness was limited to radiographs, ultrasounds, blocking and lameness exams by a veterinarian. The MRI gives owners a very specific, “goldstandard” diagnostic approach to lower limb lameness and – new hope.
THE TECHNOLOGY
To accommodate the equipment for an MRI, Moore Equine recently expanded their north facility with a specially built, climate-controlled, radio frequency wave-blocking room.
“All of the walls in this room are copper-lined to block out radio frequency waves,” says Sarah Freedman, an Animal Health Technologist (AHT or RVT) specifically trained for the MRI technology at Moore Equine.
“Everything in the room is temperature controlled and anything that can interfere with the magnet (for instance, bank cards, cell phones, pace makers, etc.) must stay behind the yellow lines.”
The MRI room at the clinic was
The specially designed room at Moore Equine houses the MRI magnet and computer and gives owners a “gold-standard” diagnostic approach to lower limb lameness. A patient’s foot is placed inside the MRI magnet, for scanning. The opposite leg (left) wears a purple bandage simply for support at this time.
carefully constructed with every vent, screw hole, and door frame lined with copper to effectively block out radio frequency waves. The ground was also scanned eight feet below for pipes; the whole operation might be akin to the design and construction that goes into building an airplane.
Utilizing a Hallmarq MRI system, the crew at Moore Equine are able to perform standing MRIs on sedated horses, which eliminates the risk and need for general anesthesia and hospitalization.
“When a horse first comes in here for an MRI, the shoes are removed and we take a radiograph of the foot to ensure there are no little nail bits that got stuck in the foot – if there is, we take all of that out. Metal bits in the foot will interfere with the magnet. Then we put a catheter in so it gives us easy access to administer sedation throughout the day.”
Depending on the level of diagnosis, an MRI procedure will take a minimum of two hours and up to two days to perform. The veterinarians and techs will take breaks throughout the procedure, so as never to go longer than two hours at a time. The process is very non-intrusive, but horses being horses, do become fidgety and agitated the longer the procedures takes.
“First off, we brush the horse to ensure it’s clean and there’s no chance of the animal tracking sawdust, hay or dirt into the room,” says Freedman.
“Then sedation is given. After that a special coil targeted to the area on the lower limb we are looking at is secured to the horse’s leg in case the horse moves. Then we gently place the horse’s foot into the magnet, allow the animal to brace itself over a chest bar, and create a comfortable place for its head to rest.”
The coils used are specific to the fetlock, carpus (knee) or tarsus (hock) and are actually what “take” the readings. The magnet sends a pulse through the coil, which then sends a reading of what it is measuring in the pulses to the technician’s computer. The MRI provides cross-section “full-slice” images of bone, fluid and soft tissue to help differentiate
between active and chronic lesions and allows veterinarians to see injuries in a way that cannot be seen with any other equipment.
THE BENEFITS
An MRI can be used to diagnose lamenesses that occur anywhere in the carpus, tarsus, or lower down the horse’s leg.
“The higher up a horse’s leg you go, the harder it is to conduct an MRI because the horse can wiggle a little bit. The horse has to be completely still because it’s very motion-sensitive,” Freedman explains.
“If anything is altered by even two degrees, it messes with the images.”
Every horse is sedated prior to an MRI, to minimize movement as the magnet is very motion sensitive.
Sarah Freedman analyses some images of a patient’s hoof.
MRIs are most commonly used for foot problems because the technology gives veterinarians a view of all the soft tissue inside that they wouldn’t normally be able to see. It will show holes in tendons, lesions, or accumulated fluid.
“If a horse has a bone problem, usually you can diagnose that with radiographs, and with soft tissue problems we normally diagnose with an ultrasound. But the MRI is incredibly beneficial for places that are hard to reach with an ultrasound,” she states.
“If the horse has a pastern issue that goes deep in the foot, which is difficult to ultrasound, the MRI could properly diagnose that area. Ultrasound can’t always penetrate deep enough within the hoof walls to get at what we need to see.”
With an MRI, vets are able to identify damage to hoof tissue, provide explanation for frustrating lameness, and offer new treatments or shoeing options. MRIs can also show fluid build-up or bruising on bones and identify early fractures before they become large problems.
“You can’t see things like the deep digital flexor tendon, superficial flexor tendon, or navicular bursa with ultrasound or xray, so the MRI is a tool vets can use to diagnose what’s going on. The MRI is also a very good diagnostic tool to show what’s going on inside a horse’s foot,” Freedman notes.
There are many reasons horse owners might want to consider an MRI. These include after diagnosing a lameness localized to the foot or lower limb by nerve blocks, having xrays taken that don’t show any noticeable injuries, monitoring treatment and healing after a significant injury has been sustained, accessing areas not visible through ultrasound, and after an acute onset of lameness during exercise.
In the specially designed room, every vent is lined with copper, to block out radio frequency waves.
THE COST
As with any diagnostic treatment, the cost of an MRI depends entirely upon how extensively the horse needs to be examined.
“At Moore Equine, a standard MRI costs $2,800, for a foot and a foot/ pastern combo. If an owner wants to see two areas, like a fetlock and a pastern, or a hock and the whole suspensory for example, that’s a complex scan and the fee is $3,300,” Freedman says.
“We always scan one leg and do the opposite leg for comparison’s sake. That
is included in the fee. Then, the scans are sent to a radiologist and there is a radiologist fee on top of everything. This usually costs anywhere from $350 US to $550 US, if she’s looking at multiple areas.”
There is a discount for any horse that has been previously scanned on a Hallmarq machine, and those files are backed up and kept at Hallmarq for an indefinite amount of time for reference.
Freedman explains that all previous scans can be accessed, no matter where in the world they were taken, and veterinarians can actually use them to note if improvements or changes can be observed at the current time. Therefore, new scans are done on previous Hallmarq patients at Moore Equine for a discounted rate of $1,500 plus the radiologist fee.
After the scans are done, the horse can go home and a report will be given as soon as the radiologist makes her findings. A veterinarian will then sit down with the horse owner at Moore Equine and carefully explain the diagnosis, plus offer possible future treatments and advice.
With equine MRI, gone are the days of labelling all equine foot lamenesses as “navicular disease.” With advanced therapies, the hope of complete rehabilitation for a variety of patients can often be realized in previously difficult-to-diagnose cases. MRIs have long been available in human medicine but it’s reassuring to know we have the technology available to our equine companions as well. For horse owners, it means difficult lameness cases may now be able to return to acceptable levels of soundness, allowing more horses to go back to their careers and improving their quality of life.
That’s an advantage many of us can’t put a price on. AB
FUNDING
Deadlines
INDIVIDUAL AND CLUB GENERAL FUNDING - April 30 -
TRAIL SUPPORTER FUNDING - May 15 -
EDUCATIONAL SCHOLARSHIPS - May 31 -
INDUSTRY SCHOLARSHIPS - May 31 -
MARLENE WALDNER YOUTH BURSARY - September 30 -
