ED Spotlight on New Technologied
Digital radiography in emergency medicine
Digital radiography has revolutionized the practice of emergency medicine, says Col. Matthew M. Rice, MD, JD, chairman and program director for the department of emergency medicine at Madigan Army Medical Center in Fort Lewis, WA. "We were one of the first hospitals in the nation to install this, and our ED was one of first places to use it. After you get used to looking at a film on a computer screen instead of a light board, it’s easy to see the benefits."
Here are some benefits of digital radiography:
Cost savings. In the past, the ED depended on hard copies of x-rays. "That involved a fair amount of expense for the film itself, and with man hours in developing, changing solutions, and making sure they were mixed properly," says Rice.
Digital radiography offers significant cost savings. "With digital technology, the investment goes in upfront with the hardware and software," says Rice. "But then it’s less expensive to run each radiograph. In an ED like ours, which sees 100,000 patients a year, you build up a lot of savings."
Quality of films. "It is very difficult to get a poor quality film using this system," says Rice. "The quality is usually almost perfect. When they are not, you can correct some minor deviations by using computer enhancement."
Previous films are easily accessible. "Past X-rays are at your fingertips," notes Rice. "All the hard copies here were scanned into the computer database. So all the old x-rays are stored in a giant disk. If at any time you want to look at a previous CT scan, ultrasound, barium enema, or chest x-ray, you just need to type in the patient’s name and identifying information."
Films can be compared easily. "We have two screens side by side, so we can compare films side by side within seconds or minutes," says Rice. "Previously, in the middle of the night, or on weekends and holidays, it was difficult to find old x-rays, and it took a fair amount of time to retrieve them."
The easy access to previous films has improved patient care. "If a patient comes in with lung problems and we take a chest x-ray, we can pull up an old film and see if the findings on the current visit were there on the previous visit," says Rice. "For example, people who have had coronary artery bypass surgery may have changes in their lungs that are weeks, months, or years old. So we can compare the new films with past films to see if the changes are new or old."
This facilitates the eventual diagnosis, Rice says. "If the patient has a small nodule and you don’t know if it’s benign or not, you don’t have to send for a new workup if it was there before and hasn’t changed," he explains. "If you suspect that a change on the x-ray may be pneumonia, you may see it was there before. So you know it was a scar of some kind instead of an acute infiltrate."
It’s possible to change and enhance the image. "The computer will actually allow us to enhance the image in ways that are almost magical," says Rice. "Before, we’d have to call a patient back and repeat a film. If we were doing a cervical spine x-ray, if the film didn’t quite show the lower thoracic and upper cervical, we might have actually had to take the patient for a CT scan to make sure there are no fractures." Digital radiography allows modification of the film, so you can actually see portions of the image more clearly, he explains.
Computer enhancements measure the density to determine if you are looking at fluid, bone, or soft tissue, says Rice. "We can also reverse the lights and darks in the image, to contrast different things," he notes. "For example, if you are looking for pneumothorax on a chest x-ray, you can see changes that suggest that better."
Storage space is saved. "In the past, we had film labs which took up lots of space. Now, films are stored in the video jukebox storage system, so we save a lot of hospital space," says Rice. "We have taken old films and digitized them for storage. If needed, we can also produce a hard copy film from the digital versions."