MRE Could Provide A Definitive Diagnosis For People With Muscle Pain, Study Shows

A Mayo Clinic study published in the November issue of the Archives of Physical Medicine and Rehabilitation shows that magnetic resonance elastography, or MRE, can provide images of the affected muscle with clarity and insight not possible with magnetic resonance imaging, or MRI. While an MRI uses a magnetic field and radio waves to create clear and detailed cross-sectional images of the body's internal tissues and organs, an MRE measures the elasticity of tissue as it is gently vibrated.

"Additional research is necessary, but our findings in this pilot study provide a strong basis to suspect that MRE technology can identify changes in muscle tone and stiffness that could previously only be identified by physical examination by a physician or a therapist," says Jeffrey Basford, M.D., Ph.D., a Mayo Clinic specialist in physical medicine and rehabilitation and an author of the study. "Prior to these findings, we did not have a good diagnostic test for myofascial pain syndrome."

An MRE employs standard MRI equipment with a few modifications, and works by measuring the wavelength of vibrations sent through the tissues. A vibrating metal plate is placed on the patient causing muscles to contract and stiffen. When this occurs, researchers can measure the elasticity of muscles and detect abnormal hardening of tissues, which in myofasical pain syndrome can cause pain.

The MRE technique is being applied to the diagnosis of other diseases, such as liver disease and could also be used to diagnose breast cancer and other tumors, which tend to be harder than the surrounding normal tissue.

Myofascial pain syndrome is sometimes confused with fibromyalgia, but the two conditions are clinically different. Fibromyalgia is a chronic condition typically characterized by widespread pain in muscles, ligaments and tendons, as well as fatigue and multiple tender points. Myofascial pain syndrome, is a more localized pain that is associated with trigger point tenderness. A trigger point is a small lump in a band of tight muscle that, when pressed, triggers a reproducible pattern of referred pain.

"In the past, myofasical pain syndrome has been very difficult to diagnose. These new findings may be the next step for a diagnosis and in the future may help to refine treatment options," Dr. Basford says.

In some chronic cases of myofascial pain, combinations of physical therapy and trigger point injections are needed to relieve pain. In addition, the condition is sometimes treated with the "spray and stretch" technique, which involves spraying the muscle and trigger point with a coolant and then slowly stretching the muscle.

The study was funded by the National Institutes of Health.

Other Mayo Clinic collaborators include Kai-Nan An, Ph.D.; Sabine Bensamoun, Ph.D.; Qingshan Chen; and Jeffrey Thompson, M.D.