ACR Meeting Abstracts

ACR Meeting Abstracts

Abstract Number: 657

First Validation of Consensus Definitions for MRI Lesions in the Sacroiliac Joint By the Assessments in Spondyloarthritis International Society MRI Group

Walter P. Maksymowych1,2, Ulrich Weber3, Susanne J Pedersen4, Xenofon Baraliakos5, Pedro Machado6, Joachim Sieper7, Denis Poddubnyy7, Stephanie Wichuk1, Joel Paschke2, Robert G. Lambert1 and Mikkel Østergaard4, 1University of Alberta, Edmonton, AB, Canada, 2CaRE Arthritis, Edmonton, AB, Canada, 3University of Southern Denmark, Odense, Denmark, 4COPECARE University of Copenhagen, Copenhagen, Denmark, 5Rheumazentrum Ruhrgebiet Herne, Herne, Germany, 6University College London, London, United Kingdom, 7Charité Universitätsmeidzin Berlin, Berlin, Germany

Meeting: 2018 ACR/ARHP Annual Meeting

Keywords: ,

Session Information

Date: Sunday, October 21, 2018

Title: Spondyloarthritis Including Psoriatic Arthritis – Clinical Poster I: Imaging, Clinical Studies, and Treatment

Session Type: ACR Poster Session A

Session Time: 9:00AM-11:00AM

Background/Purpose:

The diversity of MRI lesions in the sacroiliac joints of patients with axial spondyloarthritis (axSpA) has only recently been appreciated and consistent terminology, descriptions, and definitions have not yet been internationally accepted. The ASAS MRI group has generated updated consensus lesion definitions (ASAS_MRI_defn) and these now require validation to support widespread adoption for clinical practice and research. We aimed to assess the reliability of detection of active and structural lesions as defined by ASAS_MRI_defn on MRI images from the ASAS Classification Cohort (ASAS-CC) by 7 experts in MRI interpretation from the ASAS-MRI group.


Methods:

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. MRI images were available in a variety of formats (DICOM (n =175), JPEG (n =71), DICOM film (n =32)) and sequences, axial and semicoronal orientations, from 278 of the 495 cases who had MRI performed in the ASAS-CC. 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). Detection of lesions assessed as present/absent by global assessment was analyzed using kappa. Reliability of detailed scoring was analyzed by intraclass correlation coefficient (ICC).


Results:

Reliability of detection of active lesions was comparable irrespective of image format but structural lesions were detected more reliably on DICOM images (Table). In particular, the most frequently detected structural lesion, erosion, was detected to a comparable degree of reliability on DICOM images as the most frequently detected active lesion, subchondral inflammation. Fat metaplasia in the joint space (backfill) and ankylosis were also reliably detected despite low frequency of occurrence in this cohort. For detailed scores based on SPARCC methodology, mean (SD) was BME 4.0(9.9), erosion 2.0(2.2), fatty lesion 1.1(3.3), backfill 0.4(3.2), ankylosis 0.05(0.2). Mean ICC was BME-0.84, Erosion-0.55, Fatty lesion (any)-0.61, Fatty lesion (>1cm depth)-0.55, Sclerosis-0.73, Fat metaplasia in joint space-0.36, Ankylosis-0.97.


Conclusion:

The reliability of the ASAS_MRI_defn was substantial for the most frequently detected lesions and comparable between active and structural lesions.

 

Table. Kappa values for detection of MRI lesions in the SIJ of patients in the ASAS-CC by 7 central readers.

 

All images (n=278)

DICOM images only (n=175)

 

Mean kappa of all reader pairs (95% CI)

Mean kappa of all reader pairs (95% CI)

Active lesions typical of axSpA

0.74 (0.65-0.82)

0.70 (0.58-0.82)

Active lesions typical of axSpA (confidence ≥3)

(-4(not SpA) to +4 (SpA) NRS scale)

0.77 (0.68-0.86)

0.80 (0.69-0.92)

ASAS positive MRI

0.75 (0.66-0.83)

0.73 (0.61-0.84)

ASAS positive MRI (confidence ≥3) (1-4 scale)

0.77 (0.68-0.86)

0.79 (0.67-0.90)

Structural lesions typical of axSpA

0.64 (0.54-0.75)

0.71 (0.59-0.83)

Structural lesions typical of axSpA (confidence ≥3)

(-4(not SpA) to +4 (SpA) NRS scale)

0.62 (0.50-074)

0.75 (0.62-0.88)

Subchondral inflammation

0.65 (0.56-0.74)

0.60 (0.49-0.72)

Inflammation in erosion cavity

0.30 (0.13-0.47)

0.37 (0.15-0.58)

Capsulitis

0.40 (0.14-0.66)

0.55 (0.18-0.90)

Joint fluid

0.36 (0.21-0.50)

0.41 (0.23-0.59)

Enthesitis

0.21 (0.05-0.37)

0.23 (0.03-0.45)

Sclerosis

0.43 (0.30-0.55)

0.48 (0.33-0.63)

Erosion

0.55 (0.44-0.66)

0.61 (0.47-0.75)

Fatty lesion (any)

0.59 (0.47-0.71)

0.61 (0.46-0.76)

Fatty lesion >1cm

0.59 (0.43-0.75)

0.66 (0.47-0.84)

Fat metaplasia in joint space

0.46 (0.27-0.66)

0.50 (0.26-0.74)

Bone bud

0.13 (-0.05-0.30)

0.11 (-0.06- 0.29)

Ankylosis

0.53 (0.21-0.83)

0.58 (0.25-0.89)

 

Disclosure: W. P. Maksymowych, CaRE rthritis, 9; U. Weber, None; S. J. Pedersen, None; X. Baraliakos, None; P. Machado, None; J. Sieper, None; D. Poddubnyy, None; S. Wichuk, None; J. Paschke, None; R. G. Lambert, None; M. Østergaard, None.

To cite this abstract in AMA style:

Maksymowych WP, Weber U, Pedersen SJ, Baraliakos X, Machado P, Sieper J, Poddubnyy D, Wichuk S, Paschke J, Lambert RG, Østergaard M. First Validation of Consensus Definitions for MRI Lesions in the Sacroiliac Joint By the Assessments in Spondyloarthritis International Society MRI Group [abstract]. Arthritis Rheumatol. 2018; 70 (suppl 9). https://acrabstracts.org/abstract/first-validation-of-consensus-definitions-for-mri-lesions-in-the-sacroiliac-joint-by-the-assessments-in-spondyloarthritis-international-society-mri-group/. Accessed .

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