By Dan Ross
This spring, as the welfare crisis engulfed Santa Anita, the announcement of two cutting-edge diagnostic technologies headed to Santa Anita–one guaranteed to arrive, the other anticipated–brought hope the facility would soon provide trainers and veterinarians with a “ground-breaking” opportunity to detect earlier than ever the physical problems underlying most catastrophic injuries. Indeed, pre-existing injuries which aren't always clinically apparent are present in more than 85% of catastrophic breakdowns, studies have shown.
Months later, while the Positron Emission Tomography (PET) scan unit is expected to be trialed at Santa Anita in time to coincide with the Breeders' Cup, funding is still being sought for the standing magnetic resonance imaging (MRI) unit.
“Any equipment that we can get on the backside than can help diagnose any pre-existing conditions is going to be a game changer for us,” said Aidan Butler, The Stronach Group (TSG)'s chief strategy officer, about the newly-developed PET scan unit. “We're very excited to see the potential of this thing.”
As for the standing MRI unit, “We'll be reaching out to our industry partners” to help find the remaining funds for the machine, Butler said.
Back in May, TSG announced that it had invested $500,000–in tandem with the Dolly Green Research Foundation (DGRF), which promised a separate $250,000–to help purchase a MILE-PET Scan machine. That particular technology was, at the time, still in development.
The PET scan machine has since been built and is currently at the University of California Davis's School of Veterinary Medicine, where researchers–led by Mathieu Spriet, associate professor of Surgical and Radiological Sciences at UC Davis–are trialing the machine.
Two horses have already been scanned, and “we confirmed that the scanner is easy to use and safe for horses,” explained Spriet, in an email. He added that, should these preliminary tests proceed as anticipated, the unit will be shipped to Santa Anita the end of October, with the first clinical scan on a racehorse at the track tentatively scheduled for the 31st of that month.
“It'll just depend on the horse,” said Karen Klawitter, CEO of the Southern California Equine Foundation, about the selection process for the trial. “Say we do a [nuclear scintigraphy] scan and the ankle lights up, or the attending vet does a block, and they block to a certain area, the doctors will decide if they'd be a good candidate for this new modality,” she added.
The PET scan unit will remain at Santa Anita temporarily this time. In November, the scanner will be shipped back to UC Davis for further research purposes, before being moved permanently to Santa Anita in December for work on a 24-horse study funded by the Grayson-Jockey Club Research Foundation, explained Spriet.
Not long after Santa Anita announced its intention of bringing the new PET scan unit to the grounds, California Horse Racing Board (CHRB) equine medical director, Rick Arthur, told the TDN of possible plans to purchase and bring to Santa Anita a standing MRI machine–a technology that studies have shown detects certain lower limb issues earlier than other common imaging modalities.
Funding, however, is proving a problem for a machine with a hefty price tag of around $800,000, said Klawitter. The DGRF has pledged $450,000 towards the unit, “and we are working with TSG to find additional funding within the industry,” she said.
According to Butler, TSG will additionally fund a portion of the unit, though he didn't say how much.
Aside from the issue of funds, the process of bringing an MRI unit to Santa Anita is far from expeditious. Once an order is placed, it takes roughly six months for the unit to be built, Klawitter explained. Once finished and prior to shipment to Santa Anita, a static location would need to be prepared with a cement base for the enclosed unit to sit upon, she added. The dimensions of the standing MRI unit are 10′ x 10′ x 30′.
“So, basically we wouldn't be able to get it in here till next summer,” said Klawitter, hypothesizing a scenario whereby the funds are secured by the end of 2019.
“We're going to find room for it,” Butler added, though was unable to provide a specific location for the machine on the Santa Anita grounds at this time.
All told, there are between 60-65 standing MRIs around the world, used for multiple equine disciplines. Experts emphasize how both technologies (PET and MRI) will complement one another in the early diagnosis of injuries in the lower limb, the most common location of catastrophic injury in racehorses, the locus of these injuries typically being the fetlock.
While the new PET scan technology is still a largely untested modality in racehorses, said Arthur, many expect it to bring a heightened level of sensitivity to diagnostic imaging of the bone. “That's why the Grayson-Jockey Club though is encouraged enough to fund the clinical development of it,” he said, referencing the two-year grant awarded Spriet.
The new scanner resembles a basketball hoop hovering just above the ground, with a ring of detectors that can open freely. This means that horses won't require general anesthesia to be scanned.
The way it works is similar to a regular bone scan-the injection of a radioactive tracer that will light up under imaging any abnormal areas in the bone. The main difference being, PET scan technology results in a three-dimensional picture as opposed to two-dimensional.
“Day in, day out, MRI would probably be more clinically useful for a broader cross-section of injuries than PET scan, but PET scan will be superior we think for the sesamoid injuries that constitute the majority of the breakdowns that we deal with,” Arthur said. “Time will tell.”