NYU scientists are reporting using a novel magnetic resonance imaging method to identify early signs of osteoarthritis.
The new method uses a modified form of magnetic resonance imaging to determine the concentration of a polymer known as glycosaminogycan (GAG) that holds lots of water and gives cartilage its tough, elastic properties. GAG also is a recognized biomarker for both osteoarthritis and degenerative disc disease — a common cause of back pain. According to Jerschow, a low concentration of GAG is known to correlate with the onset of osteoarthritis and other cartilage disorders.
The diagnostic "tags" the hydrogen atoms attached to the GAGs in a way that makes them emit a signal that can be picked up by an MRI machine to determine the concentration of GAG and assess cartilage health.
Advanced OA is very easy to diagnose, Regatte points out. By then, however, joint replacement may be the only option. With early detection, physicians could prescribe dietary supplements, medication or other measures to ward off further cartilage damage.
"Given the lack of knowledge about OA, I think any method that is noninvasive and relatively easy to apply will be quite valuable. Not only do you address diagnosis, but you address how we can understand OA’s mechanism," says Jerschow.
The test could also be used to improve existing cartilage-boosting drugs, Regatte says. Currently, it’s difficult to gauge the efficacy of these drugs without a diagnostic tool to measure their effects on cartilage.
"There are drugs on the market for OA treatment, but no one really knows how effective they are. After having done the research, we got a lot of calls from pharmaceutical companies wanting to show that their drugs work," says Jerschow.