Lasers Pinpoint Joint Damage

New imaging technique could help catch rheumatoid arthritis early

THURSDAY, May 9, 2002 (HealthDayNews) -- German scientists have developed a new technique using laser imaging to measure inflammation in the finger joints of people with rheumatoid arthritis.

Much like children holding flashlights to their hands to see the bones inside, laser imaging sees through the skin and the picture is captured on a computer, says a study in this month's Arthritis and Rheumatism.

The advantages of using this device are that it's easy to use, noninvasive and inexpensive. It may also eventually provide doctors with a way to more accurately assess arthritis patients, the study says.

Rheumatoid arthritis affects more than 2 million people in the United States, reports the Arthritis Foundation. It causes inflammation of the lining of the joints, most commonly in the hands or feet. Symptoms of the disease include pain, swelling and redness of the affected joints.

Early treatment is important, because it helps stop joint damage. The problem is that early diagnosis of the disease is sometimes difficult, says study author Dr. Alexander Scheel, from the department of Nephrology and Rheumatology at Georg-August-University of Gottingen in Germany.

"Until now, conventional radiography has been the standard imaging method to detect and quantify destructive arthritis, but this method is very insensitive in detecting early erosive lesions," he says.

While he admits his laser-imaging technique can't yet be used to make an early diagnosis, Scheel says it can provide physicians with important information on a patient's response to medication and could be helpful for researchers trying to quantify the effectiveness of medications used to treat rheumatoid arthritis.

Scheel and his colleagues tested the new device on 22 rheumatoid arthritis patients over a six-month period. The patients ranged in age from 22 to 75.

The volunteers placed their hands in a holder designed to position the hand so the laser above could transmit an image to a camera below. The camera then sent the image to a computer, where the data was analyzed by special software.

When they compared the information from laser imaging to hand X-rays and doctors' evaluations, the researchers found laser imaging was 83 percent accurate in detecting changes in the amount of inflammation in the joints.

"There are no risks for the patient. The laser light has a wavelength… which is not dangerous at all, and there is no radiation," Scheel says.

However, he does acknowledge there are drawbacks to this method.

First, right now only the finger joints can be examined with this method. Also, laser light is very sensitive and changes in skin color, moisture level, room temperature, dirt on the skin or calloused skin can all cause the laser light to scatter, which would affect the quality of the image.

What To Do

Don't expect to find laser imaging in a hospital near you anytime soon. The device is still in its preliminary development stages. Scheel says more studies need to be done comparing it to traditional imaging methods.

To learn more about rheumatoid arthritis, read this information from the Arthritis Foundation.

For more information on laser imaging, go to the Lawrence Berkeley National Laboratory.

SOURCES: Alexander Scheel, M.D., department of Nephrology and Rheumatology, Georg-August-University of Gottingen, Germany; May 2002 Arthritis and Rheumatism
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