2257: MRI Spinal Lesions in Patients Without MRI or Radiographic Lesions in the Sacroiliac Joints Typical of Axial Spondyloarthritis

Walter P Maksymowych¹, Mikkel Østergaard², Xenofon Baraliakos³, Pedro Machado⁴, Susanne J. Pedersen⁵, Ulrich Weber⁶, Iris Eshed⁷, Manouk de Hooge⁸, Joachim Sieper⁹, Denis Poddubnyy¹⁰, Martin Rudwaleit¹¹, Désirée van der Heijde¹², Robert Landewé¹³ and Robert G Lambert¹⁴, ¹Department of Medicine, University of Alberta, Edmonton, AB, Canada, ²Rigshospitalet, University of Copenhagen, Glostrup, Denmark, ³Rheumazentrum Ruhrgebiet Herne, Herne, Germany, ⁴University College London, London, United Kingdom, ⁵Rigshospitalet, University of Copenhagen, Copenhagen, Denmark, ⁶Practice Buchsbaum Schaffhausen, Schaffhausen, Switzerland, ⁷Sheba Medical Center, Tel Aviv, Israel, ⁸Ghent University Hospital, Luxembourg, Luxembourg, ⁹Charité - Universitätsmedizin, Berlin, Berlin, Germany, ¹⁰Department of Gastroenterology, Infectious Diseases and Rheumatology, Charité – Universitätsmedizin Berlin, Berlin, Germany, ¹¹University of Bielefeld, Klinikum Bielefeld, Bielefeld; Germany Klinikum Bielefeld and Charité Berlin, Germany, and Gent University, Gent, Belgium, ¹²Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands, Leiden, Netherlands, ¹³Amsterdam University Medical Center, Meerssen, Netherlands, ¹⁴University of Alberta, Edmonton, AB, Canada

Background/Purpose: There is limited data as to the frequency of spinal lesions on MRI in patients without MRI or radiographic features typical of sacroiliac joint (SIJ) disease in axial spondyloarthritis (axSpA). This may inform to what degree spine MRI might enhance the diagnostic information provided by SIJ MRI alone. We aimed to assess the frequency of MRI lesions of the spine in the ASAS-Classification Cohort according to the presence of MRI SIJ lesions typical of axSpA and/or radiographic sacroiliitis according to the modified New York criteria (mNY+).

Methods: MRI spine lesions were recorded by 9 central readers in an eCRF that captures global assessment of the spine ("Is the MRI consistent with axSpA: yes/no") (yes=MRI_global spine+) and detailed anatomical-based scoring of each discovertebral unit plus lateral and posterior structures for bone marrow edema, fat lesions, erosion, and ankylosis, according to ASAS standardized definitions for spinal lesions. Independently, readers globally assessed SIJ scans for active and/or structural lesions typical of axSpA (MRI_global SIJ+) . We compared the frequency of a positive MRI_global spine+ and frequencies of different types of spinal lesions according to the presence/absence of axSpA on global evaluation of SIJ MRI scans by ≥5 of 9 readers (MRI_global SIJ+) and according to the presence/absence of mNY+ radiographic sacroiliitis using Fisher's exact test. Analysis was also stratified by rheumatologist clinical diagnosis.

Results: Among 51 cases with SIJ as well as spine MRI scans and radiographs of the SIJ,19 (37.3%) had a positive MRI_global SIJ+ scan, and 12 (23.5%) and 7 (13.7%) had a positive MRI_global spine+ scan according to ≥2 and ≥5 reader agreement, respectively. A positive MRI_global spine+ scan occurred significantly more frequently in the presence of a positive MRI_global SIJ+ scan (Table 1) and the presence of radiographic sacroiliitis but was also recorded in 4 of 32(12.5%) (≥2 readers) and 1 of 32(3.4%) (≥5 readers) cases that were negative for a MRI_global SIJ- scan and x-ray negative (Table 2), all 4 cases being diagnosed with axSpA. Moreover, vertebral corner BME lesions, but not spinal structural lesions, were significantly more frequent in cases that were negative for a MRI_global SIJ- scan but had been clinically diagnosed as axSpA versus non-axSpA (Table 3).

Conclusion: Spinal lesions on MRI indicative of axSpA per majority central read occurred in about 3% of patients without positive imaging in the SIJ on either MRI or radiography. Frequency of spinal vertebral corner BME lesions was significantly higher in cases with negative SIJ imaging on either MRI or radiography but clinically diagnosed with axSpA.
Table 1. Frequency of Spinal MRI lesions According to an MRI SIJ scan Positive for AxSpA

Table 2. Frequency of Spinal MRI lesions According to an MRI SIJ scan Positive for AxSpA and/or Presence/Absence of Radiographic Sacroiliitis (mNY+)

Table 3. Frequency of Spinal MRI lesions in Cases with Negative MRI SIJ scan for AxSpA according to Presence/Absence of Clinical Diagnosis of axSpA
Disclosures: W. Maksymowych, AbbVie, Boehringer-Ingelheim, Celgene, Eli Lilly, Galapagos, Janssen, Novartis, Pfizer, UCB, CARE Arthritis Limited; M. Østergaard, AbbVie/Abbott, Amgen, Bristol-Myers Squibb(BMS), Celgene, Eli Lilly, Janssen, Gilead, Novartis, Pfizer, UCB; X. Baraliakos, AbbVie, Lilly, Galapagos, MSD, Novartis, Pfizer, UCB, Bristol-Myers Squibb, Janssen, Roche, Sandoz, Sanofi; P. Machado, AbbVie/Abbott, Eli Lilly, UCB, Novartis, Orphazyme, Galapagos; S. Pedersen, Novartis, AbbVie/Abbott, UCB, Pfizer, Merck/MSD; U. Weber, None; I. Eshed, None; M. de Hooge, None; J. Sieper, AbbVie/Abbott, Novartis, Eli Lilly, Merck/MSD, UCB, Janssen, Pfizer, Roche; D. Poddubnyy, AbbVie, Biocad, Bristol-Myers Squibb, Eli Lilly, Gilead, GlaxoSmithKline, MSD, Moonlake, Novartis, Pfizer, Samsung-Bioepis, UCB; M. Rudwaleit, AbbVie, Bristol-Myers Squibb (BMS), Boehringer-Ingelheim, Chugai, Eli Lilly, Janssen, Novartis, Pfizer, UCB Pharma; D. van der Heijde, AbbVie, Bayer, BMS, Cyxone, Eisai, Galapagos, Gilead, Glaxo-Smith-Kline, Janssen, Novartis, Pfizer, UCB, Imaging Rheumatology bv, Lilly; R. Landewé, Abbott, Amgen, AstraZeneca, BMS, GSK, Novartis, Merck, Pfizer, Schering-Plough, UCB Pharma; R. Lambert, Calyx, CARE Arthritis, Image Analysis Group.