September Forum- Pathobiology of RA and MRI
Welcome to the September edition of #ChatJRheum
This month’s article is a systematic review of the literature that explored whether radiographic findings of synovitis on MRI correlate with histopathologic disease changes in rheumatoid arthritis (RA). If MRI findings could be correlated with histopathology, this non-invasive test could be applied to better understand the mechanisms of joint damage in rheumatoid arthritis, and further help individualize treatment.
This large review included 18 studies and a total of 442 participants, of which 327 had a diagnosis of RA. The authors reason that MRI can detect features in RA that have prognostic markers including synovitis, bone marrow edema, bone erosions and cartilage thinning.
They concluded that MRI is effective in detecting synovitis, but the literature does not support a direct link between bone marrow edema, erosions or cartilage thinning on MRI with histologic changes. The authors acknowledge there is a need for future study protocols that integrate clinical with radiographic and histopathologic measures to better understand this relationship.
I decided to highlight this article for discussion for 2 reasons. The first is to recognize the huge amount of work invested in conducting such a review. I thought this review provided valuable integration and interpretation of the literature available on this subject matter, even if the application of the work to guide personalized treatment did seem a little far-fetched.
Secondly, the findings got me thinking about my use of MRI versus ultrasound in practice. I often thought that the added information obtained from MRI not provided from ultrasound, like bone marrow edema and early erosive changes, was particularly useful in monitoring disease. So, I justified its use despite higher costs and relative scarcity. Yet, if these MRI features have not been shown to correlate with disease progression, then I ask- why would one choose MRI over ultrasound?
I look forward as always to your shared thoughts, comments or reflections.
- Dr. Sarah Troster, Forum Editor