"MRI is more sensitive for structural changes and allows diagnosis in patients without radiographic changes of spondyloarthritis," noted lead study author and musculoskeletal radiologist Dr. Srinivasan Harish of St. Joseph's Healthcare in Hamilton, Ontario."MRI reveals disease activity, which is important in patients who do not yet have structural changes, but may have spondylitis or sacroiliitis on the basis of bone marrow edema."
Researchers examined 55 referrals from three rheumatologists for MRI of the spine and sacroiliac joints to assess for spondyloarthropathy. The study measured diagnostic confidence for specific clinical findings and overall diagnosis both before and after MRI. Planned patient treatment also was evaluated before and after MRI.
Physician certainty for specific clinical findings increased significantly following MRI for inflammatory back pain, spondylitis, sacroiliitis, and mechanical back pain, Harish and colleagues found. In addition, physician certainty for overall diagnosis improved significantly for ankylosing spondylitis, undifferentiated spondyloarthropathy, and osteoarthritis.
Of the 55 patients in the study, 22 had their therapy changed following the MRI results.
"Earlier diagnosis facilitates earlier therapy," Harish added. "By assessing disease activity, unnecessary use of biological agents may be avoided and, thus, potential complications of such therapy."
In patients already taking biological agents, lack of disease activity on MRI or evidence of concomitant mechanical causes can shift the focus to additional modalities for treating back pain, rather than unnecessarily switching biological agents, he said.