Tari a 10 year-old registered quarterhorse mare (first two photos above) undergoes a spiral CT scan to examine a mass near one of her carotid arteries. The new CT scanner makes it possible to scan parts of large animals, like horses, as well as full body scans of smaller animals, like ‘Jaker,’ a dog from Oregon.
PULLMAN – WSU’s Veterinary Teaching Hospitalrecently installed a new, upgraded spiral, computed tomography (CT) scanner for use in both small and large animals, thanks to a generous gift.
The VTH has had a CT scanner for more than two decades and a magnetic resonance imaging machine (MRI) since 1996. With the new Toshiba Aquilion 16-slice spiral CT unit operational, both MRI and CT in WSU’s veterinary college are among the most advanced complementary tools for diagnostic imaging in the profession.
“Before the new CT, we only imaged a few horses a month, but now I would expect to do 10 times that”, said Professor John Mattoon, a board certified veterinary radiologist and chief of WSU’s diagnostic imaging section. There were limitations with the old technology that hampered its everyday use, but the new CT is truly state-of-the-art with brand new software that greatly improves its capabilities.Our goal is to examine 100 horses a year with the CT, and several small animals a day.
Scanning speed
Speed is one of the new CT’s main features.It can scan 1750 millimeters (mm) or about 5.75 feet of a patient’s body in 1 mm slices in 38 seconds.Twelve images per second are displayed and all 1750 digital images are delivered within three minutes.The machine’s resolution can see details as small as 0.35mm; a little more than 13/100ths of an inch.
The imaging is produced in a variety of planes as well as in three-dimensional representations of anatomic structures. A small animal can often be imaged in the new CT scanner in seconds, in many cases without general anesthesia.
A horse with a complex fracture was examined with the new CT in early June and it was completed in a couple of minutes, Mattoon said. The anesthesia and prep-work it takes to get the horse into the machine takes much longer than the actual exam.By comparison, MRI, may take an hour or more. Still, these two imaging modalities are complementary to each other, and one does not necessarily exclude the use of the other.
Horses vs.small animals
Horses are too large to fit entirely in the CT scanner, so only the head, upper neck, and lower limbs are imaged. For smaller animals, the entire body can be scanned, and is especially useful for examining the lungs and abdomen.
CT scans are the first choice in human medicine for imaging the lungs and abdomen, and I think it should become the standard of abdominal imaging in smaller animals as well, said Mattoon, who has practiced radiology for more than 25 years.
Shorter anesthesia, new research
As a result of the CT’s speed, animals have to spend much less time under anesthesia, if at all. For horses, we can use a short-acting anesthetic, and some small animals can just be sedated without undergoing anesthesia, Mattoon said. This is an important advancement because there are always risks associated with anesthetizing an animal.
Overall, CTs at WSU should be less expensive because exams take less time and anesthesia.This particular new CT scanner should also open up a whole new area of research, including vascular imaging and shunt studies. I imagine that in the beginning we will do a lot of cases in which we use both CT and MRI.
Santa Barara donors
The college received the new CT scanner through a generous donation from Joe and Barbara Mendelson of Santa Barbara, Calif. Joe and Barbara are a family long dedicated to Standardbred horses and whippets.They were made aware of WSU’s veterinary college by two of its alumni; Drs. John Oplinger (’79) and Ron Faoro (’81).
We are very privileged to have a 16-slice scanner, Mattoon said. There are scanners out there that can collect more data at one time, but to put things in perspective, the WSU veterinary college’s machine is as fast and sophisticated as any in current use with humans in the Palouse region and better than some.