Veterinary Nuclear Medicine at Illinois:
A Pioneer, a World Leader
by Carey Checca, with Archana Reddy
Veterinary technician Heather Soder steadies a mare while the nuclear medicine camera is
positioned to view its spine.
Dr. Robert Twardock, shown here with the College's first nuclear camera circa 1979, was a pioneer in using nuclear imaging in horses. His annual equine nuclear medicine workshops have trained veterinarians from around the world.
Janet Francisco, an imaging technologist, rubbed the nose of a stallion as they stood outside the steel double doors of the nuclear medicine facility. "Yes, youre a big worrier, arent you?" she says softly to the horse that had just been injected with a low-level radioisotope. Clicking her tongue, she led the horse to the beige gamma camera.
With the right foreleg of the horse near the gamma camera, Janet signaled that the horse was ready to be scanned. Dr. Sonia Crochik, the veterinary radiologist in charge of the Colleges ultrasound and nuclear medicine diagnostic lab, pressed a button and the camera read the gamma rays radiating from the animals leg. Forty seconds later, the two wall-mounted monitors flickered with the 150,000 dots that were recorded. The computer image showed a hot spota stress fracture too small to be seen in regular radiographson the shin.
"The gamma camera is an amazing tool," says Dr. A. Robert Twardock, professor emeritus of veterinary biosciences and an expert on nuclear medicine. "It gives early diagnoses, letting you see stress fractures in the bone sometimes days before youd see them in standard X-rays or with other techniques. And its non-invasive and virtually stress-free for the patient."
In 1979, the College was one of four veterinary schools that used nuclear medicine technology on animals. As pioneers in the field of equine nuclear medicine, Drs. Robert Twardock and Michael Devous used the gamma camera to extensively image horses. Using a donated camera, they developed non-invasive techniques for diagnosis of equine lameness and lung problems that otherwise went undetected by conventional diagnostic techniques.
Today, half of the 450 patients that the nuclear medicine facility diagnoses each year are horses. Most often scans are requested when thorough physical examinations, complete with regional nerve blocks and radiography, fail to pinpoint the suspected origin of lameness. "In these cases, a scan helps show exactly where radiographic evaluation should be attempted," notes Dr. Twardock. "And by getting a quick diagnosis, you can prevent breakdown by keeping the injured horse out of competition.
"We have one of the best gamma camera set-ups in the world; the camera moves in three-dimensions at the push of a button," Dr. Twardock says. The nuclear medicine facility received a new camera in February that not only has a larger field, but also has a crane and trolley system to move the camera easily about the animal. "It reduces the efforts of the staff to get the animals in just the right place. We can work more safely and it gives us great images."
A new HP-UNIX computer system captures the digital images of different modalities at a single workstation.
In addition to its reputation for equine nuclear medicine, the College has earned a reputation for the equine nuclear medicine workshops that Dr. Twardock instituted and that have been attended by veterinarians from 30 states and countries as far away as Italy and Australia.
Although the Colleges nuclear medicine department is best known for its unique contribution to equine imaging, cats and dogs have also benefited from nuclear medicine. Nuclear scintigraphy is used to detect hyperthyroidism in cats and lameness and shunts in dogs. Renal scans are done on both dogs and cats as well.
The Colleges Imaging Center has also contributed to human medicine. Drs. David Gross and Mrinal Dewanjee, veterinary biosciences, use the camera to study thrombus formation in the heart valves of swine and use their findings to improve human mechanical heart valves.
The Imaging-Radiation Therapy facility in the Veterinary Medicine Teaching Hospital boasts not only the installation of a new gamma camera, but also an upgrade of ultrasound equipment and, very soon, the arrival of state-of-the-art computed radiography equipment.
In late September, the depart-ments ultrasound equipment was upgraded. Dr. Stephen Kneller, associate professor of veterinary clinical medicine, says "The upgrade gives better resolution when imaging smaller structures such as eyes and tendons." Using the new technology, Dr. Kneller detected a tumor that was not palpable or identified by scintigraphy in the thyroid gland of a small animal patient.
Computed radiography will be added to computed tomography (CT), says Dr. John Losonsky, the section chief of the facility. The new equipment will produce a digital image the brightness and contrast of which can be manipulated for optimal resolution. Because the images will be digital, they will occupy less storage space and will be easily transmitted to different areas of the College and outside the veterinary medical teaching hospital, says Dr. Losonsky.
Dr. Robert Twardock, shown here with the Colleges first nuclear camera circa 1979, was a pioneer in using nuclear imaging in horses. His annual equine nuclear medicine workshops have trained veterinarians from around the world.