Advances in Equine Diagnostic Imaging
by bringing the PET to the table.
PET scans add a new chapter to nuclear medicine imaging. A radioactive tracer injected in the horse shows activity in the bones and soft tissues at a molecular level by detecting hot spots that illuminate injury functional change or inflammation on images.
The defining concept of the PET scan is the distinction between functional versus structural imaging.
With most imaging you are looking at the size and shape of structures says Spriet. When the bone looks abnormal its sometimes difficult to know if its abnormal because something is happening right now or if there is an old injury that is not currently active.
To perform the first equine PET scan in 2015 Spriet and his research team partnered with an engineering team from Marylandbased Brain Biosciences a company specializing in stateoftheart molecular brain imaging devices. A clinical program employing a modified human scanner imaged over 100 anesthetized horses with lameness issues.
Anesthesia carries its own level of risk to both the horse and the owners pocketbook. Four years after introducing the first scanner a standing PET for a mildly sedated horse advanced this upandcoming technology. With a standing PET a clinician positions the horses hoof into an open doughnutshaped ring before closing the apparatus around the leg. The rings detectors capture images from the hoof but it can open automatically if the horse moves.
The radioactive isotope is injected 3060 minutes prior to bringing the horse in to the room. In less than half an hour a PET scan can image both feet and fetlocks. With an MRI scan 45 minutes per foot or fetlock is necessary.
A GameChanging Future
Kelly Tisher DVM a Coloradobased veterinarian and clinic partner at the Littleton Equine Medical Center envisions future technology to scan a horses total circumference. According to Tisher several companies are actively
working to create and improve standing technology including a robotic CT machine.
Weve been hoping there would be an advancement in technology to allow standing CT imaging especially for a horses head and neck he says. Head imaging for sinus teeth or other tumors is tricky. With the neck we have an ultrasound and Xray. Still the ability to have 3D imaging and some sectional imaging and transverse imaging to learn about what different pathologies mean and what their clinical relevance is would be amazing.
Each year seeing the full picture of a horses anatomy to diagnose injury and disease matures. Centuryold
curiosity ignited a medical revolution and today veterinary researchers are casting light on more than a horses hoof.