Ultrasound touted as valuable tool for diagnosing rheumatoid arthritis
In the near future, patients with symptoms of rheumatoid arthritis will expect to see ultrasound images of what’s happening in their joints, just as mothers-to-be are given detailed views of an unborn child.
That’s the prediction of Abraham Chaiton, a Canadian rheumatologist with a mission to encourage other rheumatologists to use ultrasound in their clinical practices.
Research suggests that ultrasound is a highly effective tool for early diagnosis of rheumatoid arthritis, an auto-immune disorder that leads to inflammation of the joints and surrounding tissues. The disease affects one in 100 Canadians. Unlike osteoarthritis, rheumatoid arthritis is not age-related or caused by wear and tear of the joints.
Early detection of rheumatoid arthritis is crucial because the treatment window to achieve remission and prevent irreversible damage to the joints is about six months.
Ultrasound allows rheumatologists to see inflammation on the inside of the joint capsule, Dr. Chaiton says. Using a technique called power Doppler, rheumatologists can also detect blood flow in areas where it shouldn’t be, resulting in a precise diagnosis of inflammatory arthritis, he adds.
“The nice thing about ultrasound is it’s painless and easy to do,” Dr. Chaiton says. “It’s changed my entire approach to how I practice rheumatology.”
Patients are more accepting of aggressive treatment with powerful medications when they see ultrasound images showing active disease, he says.
Ultrasound is an invaluable tool for determining whether a drug treatment is working, he adds. Patients should switch medications if the inflammation doesn’t subside, but they may continue to have aches and pains as their condition improves. With ultrasound, he says, “you can pick up subtle changes.”
Unlike routine ultrasounds done in standard labs, rheumatologists do targeted ultrasounds on joints and tendons to detect inflammation using high-frequency probes, Dr. Chaiton says. Radiologists, who read x-rays and other diagnostic scans, rarely meet patients, whereas a rheumatologist interprets images while taking into account the patient’s history and overall condition.
“It’s a point-of-care tool that should be in every rheumatologist’s office,” he says.
Ultrasound has been widely used by rheumatologists in Europe for about 25 years. In Canada, however, the majority of rheumatologists are untrained in ultrasound. Instead, they examine hands, feet and limbs for signs of inflammation and listen intently to patients’ reports of pain.
As of yet, Ontario and Quebec are the only provinces to allow limited billing for ultrasound services from rheumatologists. And until a year ago, there was no ultrasound training available for rheumatologists in Canada.
Nevertheless, there are signs that ultrasound is gaining ground. Out of an estimated 350 rheumatologists in Canada, 50 have received ultrasound training from the Canadian Rheumatology Ultrasound Society, an organization co-founded by Dr. Chaiton in 2010.
At least 30 graduates of the training are now using ultrasound in their offices, notes Maggie Larché, a rheumatologist at McMaster University and a vice-president of CRUS. But she adds that many are doing so at their own expense due to lack of provincial compensation.
In Ontario, rheumatologists have successfully lobbied the ministry of health to introduce a billing code for ultrasound-guided injections, which are more effective and less painful than standard “blind” injections, Dr. Chaiton says.
Despite these gains, however, there is no clear consensus among Canadian rheumatologists that ultrasound should be standard practice. The Canadian Rheumatology Association is set to weigh the pros and cons of ultrasound in a debate next week at a national conference in Victoria.
Using ultrasound requires expensive equipment – a basic setup costs about $30,000 – and takes more time than a typical patient exam, notes Christopher Penney, a professor of rheumatology at the University of Calgary who will argue against widespread adoption of ultrasound in the debate.
He points to a literature review showing that an ultrasound evaluation can take anywhere from 15 to 60 minutes, and that the minimum number of joints that should be included in an ultrasound exam is difficult to determine.
Dr. Penney adds that he is in favour of provincial funding of ultrasound in rheumatology. But he suggests the number of practitioners using ultrasound will likely remain small because of the time and effort required.
Dr. Penney argues that if a sizable number of rheumatologists start using the technology, they will end up treating fewer patients because of the additional time required to perform ultrasounds. “We already don’t have enough rheumatologists in Canada,” he writes in an e-mail.
But Dr. Chaiton predicts ultrasound will attract more medical students to the field of rheumatology. He points out that students are drawn to high-tech specialties such as cardiology. Now that rheumatology can offer sophisticated equipment and technological expertise, “it’s much more attractive to students,” he says.