Session Information
Date: Monday, October 22, 2018
Title: Spondyloarthritis Including Psoriatic Arthritis – Clinical Poster II: Clinical/Epidemiology Studies
Session Type: ACR Poster Session B
Session Time: 9:00AM-11:00AM
A broad spectrum of MRI lesions has been described in the sacroiliac joint (SIJ) of patients with axial spondyloarthritis and a recent consensus from the ASAS MRI group has culminated in updated lesion definitions (ASAS_MRI_defn). There has been no detailed evaluation of MRI scans from the ASAS Classification Cohort (ASAS-CC)1 to determine the spectrum of MRI lesions in the SIJ in this cohort according to these definitions. We conducted a multi-reader exercise of ASAS-CC MRI scans comprising 7 experts from the ASAS-MRI group to compare the frequencies and specificity of different lesion types according to diagnostic category.
ASAS_MRI_defn were recorded in an eCRF that comprises global assessment (lesion present/absent), links to reference images, and detailed scoring (SPARCC SIJ inflammation, SPARCC SIJ structural). MRI images were available from 278 of the 495 cases that had MRI performed in the ASAS-CC and were available in a variety of formats (DICOM (n =175), JPEG (n =71), DICOM film (n =32)) and sequences, axial and semicoronal orientations. Image quality was considered sufficient for global assessment in all cases by all readers. Detailed SPARCC scoring data was based only on assessment of images in DICOM format (n =175). Comparison of active and structural lesion frequencies was assessed according to individual and majority agreement (≥4/7 readers) data. MRI lesions were compared between axial SpA and non-axial SpA back pain patients according to diagnostic ascertainment by local rheumatologists.
Active and structural lesions discriminated equally well between axSpA and non-axSpA patients, and the frequency of active and structural lesions in each subgroup of patients was comparable. SPARCC BME, erosion, and fatty lesion scores were significantly higher in those with axSpA (Table). 8.6% and 11.4% of axSpA and non-axSpA, respectively, had subchondral BME which was not deemed typical of axSpA. Inflammation in the erosion cavity and enthesitis were only reported in axSpA. Erosion was the most frequently observed structural lesion (36.6%) followed by fatty lesion (25.2%) in patients with axSpA with <5% of non-axSpA having these lesions.
In this first central reader analysis of MRI images from the ASAS-CC we demonstrate similar frequencies of active and structural lesions typical of axSpA. Erosions and fatty lesions are common structural lesions in axSpA. Some degree of subchondral inflammation, which was not considered typical of axSpA, was also detected, both in axSpA and non-axSpA.
1. Rudwaleit et al. Ann Rheum Dis 2009;68: 777-831.
Table. Frequencies of MRI lesions in the SIJ in the ASAS-CC (majority reader (≥4/7) data).
|
Variable |
Local Rheumatologist Diagnosis |
P VALUE |
|
|
AxSpA (n=199) |
NOT AxSpA (n=77) |
||
|
Active lesions typical of axSpA and meets ASAS definition for positive MRI |
85 (42.7%) |
2 (2.6%) |
<0.0001 |
|
Subchondral inflammation |
102 (51.3%) |
10 (13.0%) |
<0.0001 |
|
Inflammation in erosion cavity |
20 (7.2%) |
0 (0%) |
0.0014 |
|
Capsulitis |
8 (2.9%) |
0 (0%) |
0.11 |
|
Joint Fluid |
16 (8.0%) |
2 (2.6%) |
0.17 |
|
Enthesitis |
14 (5.0%) |
0 (0%) |
0.013 |
|
SPARCC BME score, mean (SD) |
5.9 (11.8)
|
0.4 (0.6)
|
0.0006 |
|
Structural lesions typical of axSpA |
69 (39.4%) |
6 (9.7%) |
<0.0001 |
|
Structural lesions typical of axSpA and level of confidence ≥3 (scale of 1-4) (-4(not SpA) to +4 (SpA) NRS scale) |
48 (27.4%) |
2 (3.2%) |
<0.0001 |
|
Subchondral sclerosis |
32 (18.3%) |
8 (12.9%) |
0.26 |
|
Erosion |
64 (36.6%) |
3 (4.8%) |
<0.0001 |
|
Fatty lesion (any) |
44 (25.1%) |
3 (4.8%) |
0.0001 |
|
Fatty lesion (>1cm) |
20 (11.4%) |
3 (4.8%) |
0.14 |
|
Bone bud (yes) |
1 (0.6%) |
0 (0%) |
1.00 |
|
Fat metaplasia in joint space |
16 (9.1%) |
2 (3.2%) |
0.17 |
|
Ankylosis |
6 (3.4%) |
0 (0%) |
0.19 |
|
SPARCC erosion score, mean (SD) |
2.7 (4.8) |
0.7 (2.2) |
0.0032 |
|
SPARCC fatty lesion (any), mean (SD) |
3.0 (6.1) |
0.6 (3.5) |
0.0065 |
|
SPARCC fatty lesion (>1cm), mean (SD) |
1.4 (3.7) |
0.3 (2.3) |
0.041 |
|
SPARCC sclerosis, mean (SD) |
1.8 (4.1) |
1.5 (5.5) |
0.69 |
|
SPARCC backfill, mean (SD) |
0.6 (3.9) |
0.01 (0.06) |
0.26 |
|
SPARCC ankylosis, mean (SD) |
0.06 (0.2) |
0.04 (0.2) |
0.54 |
To cite this abstract in AMA style:
Maksymowych WP, Pedersen SJ, Baraliakos X, Machado P, Weber U, Sieper J, Wichuk S, Poddubnyy D, Østergaard M, Paschke J, Lambert RG. Frequency and Specificity of MRI Lesions in the Sacroiliac Joints of Patients with Axial Spondyloarthritis and Non-Specific Back Pain: First Analysis of MRI Scans from the Assessments in Spondyloarthritis International Society Classification Cohort [abstract]. Arthritis Rheumatol. 2018; 70 (suppl 9). https://acrabstracts.org/abstract/frequency-and-specificity-of-mri-lesions-in-the-sacroiliac-joints-of-patients-with-axial-spondyloarthritis-and-non-specific-back-pain-first-analysis-of-mri-scans-from-the-assessments-in-spondyloarthr/. Accessed .« Back to 2018 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/frequency-and-specificity-of-mri-lesions-in-the-sacroiliac-joints-of-patients-with-axial-spondyloarthritis-and-non-specific-back-pain-first-analysis-of-mri-scans-from-the-assessments-in-spondyloarthr/