0:03
Hello, my name is Atul Devdar. I'm a rheumatologist at Oregon Health and Science University in Portland, Oregon.
0:10
And I'm reporting from the RheumNow booth here at the ACR Convergence in 2026.
0:15
And I wanted to speak a little bit about a new trend that we are observing in the field of spondyloarthritis.
0:25
This is related to structural lesions and how they are more important than the inflammatory lesions in the sacroiliac joints, and the old definition of positive MRI.
0:37
This is the ASAS definition of positive MRI from 2009.
0:40
You know that definition — that if you see two white spots or bone marrow edema lesions on the STIR image on two consecutive slices, or two lesions on a single slice, then that was thought to be a positive MRI for axial spondyloarthritis.
1:00
This was the old 2009 definition. There was no importance given to structural lesions.
1:05
What we found out was that that definition was too sensitive, and even normal people, people with mechanical back pain, athletes, etc. used to have — or can have — that type of lesion, and they certainly do not have axial spondylitis.
1:23
In the last few years, and more recently, we are now finding that structural lesions — and by structural lesions I mean erosions, fat lesions, sclerosis, ankylosis, and backfill — there are five different structural lesions.
1:41
These are more important and even more common than inflammatory lesions in the sacroiliac joint.
1:47
SPARTAN and SSR, which is the Society of Skeletal Radiology, came together, and the definition has now changed.
1:57
We are not calling it positive MRI. We are calling it MRI indicative of axial spondyloarthritis.
2:03
This is the latest 2026 definition of MRI indicative of axial spondyloarthritis, in which the structural lesions have been given more weight.
2:13
Now, why is this important? This is very important because the 2025 CLASSIC study was completed, and in that CLASSIC study, MRI is the most important item for classification of somebody with axial spondyloarthritis, which carries eight points.
2:34
So it is important that we come out with what is MRI indicative of axial spondyloarthritis.
2:41
There are a couple of abstracts presented at this particular meeting which look back at the CLASSIC study, and what was found out was that in the CLASSIC study, 25–29% of the patients were found to have axial spondyloarthritis amongst all the patients seen in that study.
3:00
When those MRIs were looked at, only 1% of those MRIs had pure inflammatory lesions, 72% of those MRIs had a combination of inflammation and structural lesion, and 25% of them had only structural lesions.
3:15
So the take-home points are: structural lesions are probably more important than inflammatory lesions.
3:22
We need to be educating our musculoskeletal radiologists.
3:25
And very soon, the SPARTAN and SSR — which is the Society of Skeletal Radiology — MRI indicative of axial spondyloarthritis definition will be published in Arthritis and Rheumatology. So watch this space.
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