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Power and portability are the hallmarks of today's imaging technology.
Being able to easily carry the equipment into the field—literally—and still get top-quality imaging has made the equine practitioner's job less cumbersome and more efficient.
"The real benefit is from the diagnostic standpoint while you're standing beside the horse," said Dave Stearns, national sales manager for Idexx Laboratories, based in Westbrook, Maine, a manufacturer of portable imaging systems, "The veterinarian can make a diagnosis, prescribe treatment and drive away."
Digital technology enables the veterinarian to view images within seconds after taking them. Then he can identify areas that warrant closer scrutiny for subsequent imaging. Unsatisfactory views can be discarded and retaken—all without having to return to the clinic to process the film.
Processing software offers the ability to enhance the images to uncover subtle changes that might not be visible using traditional X-ray film, and archiving systems make it possible to store images on the practitioner's laptop computer.
For ongoing cases, the practitioner can retrieve previous images of the horse's injury on the spot for comparison to determine the extent of healing and the effectiveness of the treatment protocol.
"The trend in the future is digital imaging," said Joe Hecker, president of Diagnostic Imaging Systems, in Rapid City, S.D. "There are three types of digital imaging available: one is computed radiography, which uses plates similar to a regular cassette that is used now, and that plate is removed and scanned by a laser to produce a digital image. "The second type is digital radiography, which uses a digital cassette, so there is no plate to remove and scan. The third type is the charge coupled device system that uses an array of camera tubes to image the digital information by focusing those cameras on a phosphorous screen like a regular cassette would use, and it's converted into digital without having to do anything additional."
Three years ago, Idexx introduced its Idexx-CR Compact, a 35-pound unit that runs on 110-volt power or from an inverter in the practice vehicle.
"It's a portable computed radiography and digital scanning device that runs with a laptop computer," Stearns said.
"It comes with a laptop and software that is specific to equine anatomy. It's primarily used in equine because the only plate size that will fit in it is 8 inches by 12 inches.
"The whole system includes the plate reader, four plates and cassettes, the laptop, the Idexx PACS, and filters that are specific to equine anatomy.
"PACS is a term from human medicine that stands for picture archive communication system. It archives and stores the images on the computer's hard drive, and this system comes with a high-end laptop."
Diagnostic Imaging's contribution to the portable imaging trend is the Ultra 9015. Hecker said it has a number of features that benefit practitioners. "The No. 1 situation that gets doctors in trouble when they are doing field radiology with a portable X-ray machine is the actual line power required to operate the equipment. This unit can operate using up to a 150-ft. extension cord," Hecker said.
"They may not need to use it on a 150-ft. cord, but sometimes they might have to if they are in a large barn or in an arena and have to string it across to where the animal is lying to treat it. This works on a regular 16-gauge extension cord, and that's a big feature.
"Another advantage of this unit is that it is the lightest unit on the market with a 20,000 focal heat unit X-ray tube. That tells you how much workload this machine can do before the tube is stressed. This unit weighs about 17 1/2 pounds. It is really helping to revolutionize portable radiology, primarily for equine doctors."
John Ismay, DVM, a large animal practitioner at Sturgis Veterinary Hospital and Equine Center in S. D., has several portable imaging devices, but he prefers the Ultra 9015 because of its laser sighting device. Dual laser pointers indicate cassette centers, and the convergence point indicates the proper distance.
"This machine not only has the laser sight, but it also has a light collimator.," Dr. Ismay said. You just fill the cassette with the light—it has cross-hairs on it. This laser sight has one light on each side and they cross right at 66 centimeters. So that's a real advantage, not only with distance but it also helps to make sure that the X-ray fills the cassette."
The laser pointer is often used for bright ambient light applications where the traditional halogen collimator lamps cannot produce enough brightness to identify the X-ray field center. It can indicate the X-ray beam center even in very bright daylight and makes it easy to position the X-ray cassette via a bright red laser dot in the center of the collimated X-ray field.
"We use this unit both with computed radiology and traditional X-rays, and we average about 30 X-rays per day," Ismay said.
Eklin Medical Systems of Sunnyvale, Calif., introduced its portable unit, the EDR1, during the 2003 Rolex Kentucky Three-Day Event. Eklin designs and manufactures the direct-capture digital radiography and image management systems for the veterinary care market.
The EDR1, which weighs 6.2 pounds, uses a conventional X-ray camera, but the data is captured on a digital cassette attached via cable to a portable processor. Patient information is entered by the veterinarian via a touch screen that looks like a keyboard.
This unit and the larger EDR5 were part of a digital radiography conversion adopted by the University of Pennsylvania's New Bolton Center last year.
X-rays taken in the field can be viewed on the EDR1's high-resolution screen using software that enables the veterinarian to manipulate the images to obtain the best possible results.
Gary Cantu, president of Eklin, emphasized that a high-resolution monitor is the key to taking full advantage of the technology.
"The monitor is really what makes the difference in being able to see a lot of detail," he said. "This new imaging technology tremendously adds to what we are able to diagnose and, therefore, actually do something about."
Michael Walker, DVM, head of the large animal radiology section and professor of radiology at Texas A&M University, said high-generation portable imaging devices are an indication of continuing advancement in veterinary radiology.
"I think there is going to be an increasing tendency in veterinary medicine, just as there is in human medicine, for diagnostic imaging to go in the direction of filmless imaging, in other words, toward digital imaging," Dr. Walker said.
He added that, although the current trend is for small practices to move to powerful, more efficient portable imaging devices, radiology services provided by university veterinary hospitals and large clinics using high-powered radiography will still be a mainstay in veterinary medicine.
Denise Steffanus is a frequent contributor to Veterinary Practice News.
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