Real Pet Scanning

MR is going to the dogs ... and cats ... and horses ... maybe the occasional gorilla.

A Solon OH, company, Universal Medical Systems, is marketing a clam-shaped scanner it describes as the world's first dedicated MRI system for small and large animals.

The Vet-MR Grande is sold through Universal Medical Systems, which has already placed 10 of the units, including one to the University of Pennsylvania School of Veterinary Medicine. Manufactured by Esaote, arguably the world's most successful maker of niche MR scanners, the MR Grande can do whole-body images of animals the size of cats and dogs. When it comes to horses, however, its field-of-view is restricted to heads, necks, and legs.

It was just a matter of time until someone started making MR systems for pets. Veterinarians have been using x-ray and ultrasound equipment for decades.

But even these are limited in what they can tell vets about their patients. MR can fill in a lot of gaps.

"The Vet-MR Grande offers veterinarians and their equine patients an exponentially improved ability to accurately diagnose the cause of lameness, as well as sinus, neurological, and cervical problems," said Dr. Alexia McKnight, an assistant professor of radiology at the Penn's School of Veterinary Medicine. "It will lead to more effective treatments for our greatest equine athletes as well as the beloved 'backyard' pleasure horse."

McKnight and colleagues at Penn have been using the Vet-MR Grande system since July 2005. The scans are done at the school's large-animal facility, New Bolton Center, in Kennett Square.

Staff at Cornell University College of Veterinary Medicine have applied veterinary MR since November 2004, when UMS installed North America's first dedicated veterinary MR system for companion pets.

Dedicated veterinary MR offers benefits for patients who walk on two legs as well as four. When veterinary units are not available, animals have visited medical centers, albeit after hours. One such case occurred last year, when a caregiver at the San Diego Zoo noticed a limp in a 36-year-old female western lowland gorilla. The gorilla's condition grew progressively worse, until finally she could no longer walk. When radiographs did not lead to a final diagnosis, an MR of her cervical, thoracic, and lumbar spine was carried out - under anesthesia, of course. The gorilla was found to have a large herniated disk at the L1-2 level on the right. Surgical laminectomy was performed. Within two weeks, she was walking without even a noticeable limp.

MR experiences for other animals, however, have not always turned out so well. The problem begins with the examination. Until now, MR scanners have been built for people. Vet-MR Grande is designed specifically for animals with a positioning system to stabilize the animal and protocols suited to nonhuman anatomies.

It is, apparently, just what the vet ordered.