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Objective To perform region-based development of whole-body MRI through validation of knee region scoring systems in spondyloarthritis (SpA). Methods Assessment of knee inflammatory pathologies using 2 systems, OMERACT MRI Whole-body score for Inflammation in Peripheral joints and Entheses (MRI-WIPE) and Knee Inflammation MRI Scoring System (KIMRISS), in 4 iterative multi-reader exercises. Results In the final exercise, reliability was mostly good for readers with highest agreement in previous exercise. Median pairwise single-measure ICCs for osteitis and synovitis/effusion status/change were 0.71/0.48 (WIPE-osteitis), 0.48/0.77 (WIPE-synovitis/effusion), 0.59/0.91 (KIMRISS-osteitis) and 0.92/0.97 (KIMRISS-synovitis/effusion). SRMs were 0.74 (WIPE-synovitis/effusion) and 0.78 (KIMRISS-synovitis/effusion). Conclusion MRI-WIPE and KIMRISS may both be useful in SpA whole-body evaluation studies.

ObjectiveTo assess the diagnostic accuracy of radiography (X-ray, XR), CT and MRI of the sacroiliac joints for diagnosis of axial spondyloarthritis (axSpA).Methods163 patients (89 with axSpA; 74 with degenerative conditions) underwent XR, CT and MR. Three blinded experts categorised the imaging findings into axSpA, other diseases or normal in five separate reading rounds (XR, CT, MR, XR +MR, CT +MR). The clinical diagnosis served as reference standard. Sensitivity and specificity for axSpA and inter-rater reliability were compared.ResultsXR showed lower sensitivity (66.3%) than MR (82.0%) and CT (76.4%) and also an inferior specificity of 67.6% vs 86.5% (MR) and 97.3% (CT). XR +MR was similar to MR alone (sensitivity 77.5 %/specificity 87.8%) while CT+MR was superior (75.3 %/97.3%). CT had the best inter-rater reliability (kappa=0.875), followed by MR (0.665) and XR (0.517). XR +MR was similar (0.662) and CT+MR (0.732) superior to MR alone.ConclusionsXR had inferior diagnostic accuracy and inter-rater reliability compared with cross-sectional imaging. MR alone was similar in diagnostic performance to XR+MR. CT had the best accuracy, strengthening the importance of structural lesions for the differential diagnosis in axSpA.

Objective.To establish the prevalence of nonradiographic sacroiliitis within a real-life sample of patients with psoriatic arthritis (PsA), using pelvic radiographs and magnetic resonance imaging (MRI) of sacroiliac joints (SIJs).Methods.This cross-sectional study included 107 consecutive adults with PsA (Classification Criteria for Psoriatic Arthritis criteria). Participants completed clinical and laboratory evaluation, pelvic radiographs scored for radiographic sacroiliitis according to the modified New York (mNY) criteria, and noncontrast MRI of SIJs, scored by the Berlin score and categorized into active sacroiliitis using the 2016 Assessment of Spondyloarthritis international Society (ASAS) criteria and the presence of structural sacroiliitis.Results.Radiographic sacroiliitis/mNY criteria were detected in 28.7% (n = 29), confirmed by MRI-detected structural lesions in 72.4% (n = 21). Active sacroiliitis was detected by MRI in 26% (n = 28) of patients, with 11% (n = 11) qualifying for nonradiographic sacroiliitis. Patients with radiographic and nonradiographic sacroiliitis had similar clinical characteristics, except for a longer duration of psoriasis (PsO) and PsA in the radiographic subgroup (PsO: 23.8 ± 12.5 vs 14.1 ± 11.7 yrs, P = 0.03; PsA: 12.3 ± 9.8 vs 4.7 ± 4.5 yrs, P = 0.02, respectively). Inflammatory back pain (IBP) was reported in 46.4% (n = 13) with active sacroiliitis and 27% (n = 3) with nonradiographic sacroiliitis. The sensitivity of IBP for detection of nonradiographic sacroiliitis was low (27%) and moderate for radiographic sacroiliitis (52%), whereas specificity ranged from 72% to 79% for radiographic and nonradiographic sacroiliitis, respectively.Conclusion.The prevalence of active sacroiliitis among a real-life population of patients with PsA was 26%. However, the prevalence of nonradiographic sacroiliitis was low (11%) compared to the radiographic sacroiliitis (28.7%) seen in patients with longer disease duration. IBP was not a sensitive indicator for the presence of early-stage sacroiliitis that was commonly asymptomatic.

Study Design: Efficacy study. Objectives: To elucidate the limitations of radiography in patients with spinal ankylosing disorders (SAD) with an emphasis on thoracolumbar injuries, which have been less focused upon. Methods: We searched our hospital’s emergency room database for patients who underwent a total spine computed tomography (CT) following a diagnosis of SAD on radiographs following a minor fall. A high-quality presentation containing 50 randomly situated anteroposterior + lateral radiographs was created. Of these, 24 contained a hyperextension type fracture diagnosed by CT. Twelve physicians—4 spine surgeons, 4 senior orthopedic residents and 4 junior orthopedic residents were requested to identify the pathologic radiographs and note the fracture level. Results: Fracture diagnosis stood at 65% for the best reader. When examining the different subgroups, the mean rate of diagnosis for spine surgeons was 55% and for orthopedic residents 32%. Mean diagnosis of thoracic fractures was 26%, of lumbar fractures was 55%, and for the entire thoracolumbar spine was 40%. The interobserver agreement (kappa coefficient) was found to be 0.37 for the entire group and 0.39 for spine surgeons. This finding was statistically significant. Conclusions: The simple radiograph is an inefficient modality for diagnosis of hyperextension type thoracolumbar fractures in patients with SAD. The poor interobserver agreement rate further amplifies this finding. Advanced imaging is recommended in these patients.

Objectives To determine quantitative SI joint MRI lesion cut-offs that optimally define a positive MRI for inflammatory and structural lesions typical of axial SpA (axSpA) and that predict clinical diagnosis. Methods The Assessment of SpondyloArthritis international Society (ASAS) MRI group assessed MRIs from the ASAS Classification Cohort in two reading exercises where (A) 169 cases and 7 central readers; (B) 107 cases and 8 central readers. We calculated sensitivity/specificity for the number of SI joint quadrants or slices with bone marrow oedema (BME), erosion, fat lesion, where a majority of central readers had high confidence there was a definite active or structural lesion. Cut-offs with ≥95% specificity were analysed for their predictive utility for follow-up rheumatologist diagnosis of axSpA by calculating positive/negative predictive values (PPVs/NPVs) and selecting cut-offs with PPV ≥ 95%. Results Active or structural lesions typical of axSpA on MRI had PPVs ≥ 95% for clinical diagnosis of axSpA. Cut-offs that best reflected a definite active lesion typical of axSpA were either ≥4 SI joint quadrants with BME at any location or at the same location in ≥3 consecutive slices. For definite structural lesion, the optimal cut-offs were any one of ≥3 SI joint quadrants with erosion or ≥5 with fat lesions, erosion at the same location for ≥2 consecutive slices, fat lesions at the same location for ≥3 consecutive slices, or presence of a deep (i.e. >1 cm depth) fat lesion. Conclusion We propose cut-offs for definite active and structural lesions typical of axSpA that have high PPVs for a long-term clinical diagnosis of axSpA for application in disease classification and clinical research.

ObjectivesThe Assessment of SpondyloArthritis international Society (ASAS) MRI working group (WG) was convened to generate a consensus update on standardised definitions for MRI lesions in the sacroiliac joint (SIJ) of patients with spondyloarthritis (SpA), and to conduct preliminary validation.MethodsThe literature pertaining to these MRI lesion definitions was discussed at three meetings of the group. 25 investigators (20 rheumatologists, 5 radiologists) determined which definitions should be retained or required revision, and which required a new definition. Lesion definitions were assessed in a multi-reader validation exercise using 278 MRI scans from the ASAS classification cohort by global assessment (lesion present/absent) and detailed scoring (inflammation and structural). Reliability of detection of lesions was analysed using kappa statistics and the intraclass correlation coefficient (ICC).ResultsNo revisions were made to the current ASAS definition of a positive SIJ MRI or definitions for subchondral inflammation and sclerosis. The following definitions were revised: capsulitis, enthesitis, fat lesion and erosion. New definitions were developed for joint space enhancement, joint space fluid, fat metaplasia in an erosion cavity, ankylosis and bone bud. The most frequently detected structural lesion, erosion, was detected almost as reliably as subchondral inflammation (κappa/ICC:0.61/0.54 and 0.60/0.83) . Fat metaplasia in an erosion cavity and ankylosis were also reliably detected despite their low frequency (κappa/ICC:0.50/0.37 and 0.58/0.97).ConclusionThe ASAS-MRI WG concluded that several definitions required revision and some new definitions were necessary. Multi-reader validation demonstrated substantial reliability for the most frequently detected lesions and comparable reliability between active and structural lesions.

Background Takayasu arteritis (TA), a systemic large-vessel vasculitis, was reported to have high incidence of spondyloarthropathy. Purpose To evaluate the prevalence of inflammatory sacroiliitis in patients with TA that underwent abdominal/pelvic magnetic resonance imaging (MRI) examinations as part of their vasculitis work-up. Material and Methods Consecutive abdominal/pelvic MRI examinations of 34 patients with TA fulfilling the 1990 ACR criteria and 34 age- and gender-matched controls performed between 2008 and 2020 were retrospectively reviewed for the presence sacroiliitis. The presence of active and structural lesions was scored twice (with a one-month interval between reads) by one reader. Structural lesions were also evaluated on computed tomography, when available, and correlated to MRI findings. Clinical data were extracted from the patients’ clinical files. MRI scores were compared between the study and control groups and correlated with the clinical data. Results Sacroiliitis was evident in 11.7% of the TA group examinations compared to 0.3% in the control group ( P = 0.6). Participants with TA had significantly more erosions and fat deposition compared to the control group (Study: 0.01/0.03, Control: 0/0, P = 0.03/0.003, respectively). However, mean sacroiliitis score was not significantly different (Study: 1.06, Control: 0.78, P = 0.015). Of the four patients with TA and sacroiliitis, 3 (75%) had a diagnosis of inflammatory bowel disease (IBD). Conclusion Sacroiliitis was detected in 11.7% of abdominal MRI examinations of patients with TA, 75% of which had associated IBD, suggesting that both IBD and sacroiliitis should be routinely screened in the TA population as their presence may influence treatment decisions.

Purpose To reassess the diagnostic approach to a patient with a monoarticular disease in light of the up-to-date medical literature and to examine the practical utility of traditional and newer imaging tools in the setting of monoarthritis. Results The monoarticular disease can represent a medical emergency on the one hand and be a diagnostic conundrum on the other. The management rules of patients with monoarthritis have been established long ago, but various pitfalls still lead physicians off the right diagnosis at times. Septic, pseudoseptic arthritis and hemarthrosis are the most common diagnoses made in patients with an acute presentation, and a decision not to perform a diagnostic arthrocentesis is the most prevalent cause of misdiagnosis in this setting. Many rheumatic and infectious diseases can present with more indolent monoarthritis; careful history and physical examination frequently provide clues to the straightforward diagnosis in some cases, but the extensive investigation is needed in others. Imaging methods become indispensable in individuals with the non-inflammatory monoarticular disease, with magnetic resonance imaging being the gold standard for diagnosing pigmented villonodular synovitis, lipoma arborescence, avascular necrosis, or neuropathic arthropathy. Conclusions A great variety of medical disorders can present as a monoarticular disease. The disease presentation dictates different diagnostic behavior, while knowing the available imaging methods' diagnostic potential should further shorten the diagnostic process.

Objectives To report the discrepancies and agreements between US, MRI and radiography of the hand in PsA, and to compare the sensitivity and specificity of US and radiography to MRI as the gold standard imaging study in PsA. Methods All of the 100 prospectively recruited consecutive PsA patients underwent clinical assessment and concomitant radiographic, US and MRI studies of the MCP, PIP and DIP joints of one hand. Synovitis, flexor tenosynovitis, extensor paratenonitis, erosions and bone proliferations were identified and scored. All readers were blinded to clinical data, and agreement was calculated based on prevalence-adjusted bias-adjusted kappa (PABAK). Results The prevalence of synovitis, flexor tenosynovitis, extensor paratenonitis and erosions was similar for US and MRI, while that of bone proliferation was significantly increased in US and radiography compared with MRI (P Conclusion There is very good agreement between US and MRI for the detection of inflammatory changes in finger joints in PsA. US, radiography and MRI have a good-to-very good agreement for destructive changes.

Diffuse Idiopathic Skeletal Hyperostosis (DISH) is considered a metabolic condition, characterized by new bone formation affecting mainly at entheseal sites. Enthesitis and enthesopathies occur not only in the axial skeleton but also at some peripheral sites, and they resemble to some extent the enthesitis that is a cardinal feature in spondyloarthritis (SpA), which is an inflammatory disease. We review the possible non-metabolic mechanism such as inflammation that may also be involved at some stage and help promote new bone formation in DISH. We discuss supporting pathogenic mechanisms for a local inflammation at sites typically affected by this disease, and that is also supported by imaging studies that report some similarities between DISH and SpA. Local inflammation, either primary or secondary to metabolic derangements, may contribute to new bone formation in DISH. This new hypothesis is expected to stimulate further research in both the metabolic and inflammatory pathways in order to better understand the mechanisms that lead to new bone formation. This may lead to development of measures that will help in earlier detection and effective management before damage occurs.

Objective.Whole-body MRI (WBMRI) is a promising technique for monitoring patients’ global disease activity in inflammatory joint diseases. The validation of WBMRI is limited; no studies have evaluated the test-retest agreement (interscan agreement) and only a few have assessed the intra- and interreader agreement. Therefore, we first examined the interscan agreement of WBMRI in patients with psoriatic arthritis (PsA), rheumatoid arthritis (RA), and healthy controls (HC); and second, we evaluated the intra- and interreader agreement and agreement with conventional hand MRI and determined the distribution of lesions.Methods.WBMRI was performed twice at a 1-week interval in 14 patients with PsA, 10 with RA, and 16 HC. Images were anonymized and read in pairs with unknown chronological order by experienced readers according to the Outcome Measures in Rheumatology (OMERACT) WBMRI, Canada-Denmark MRI, and the RA MRI scoring system (RAMRIS) and the PsA MRI scoring system (PsAMRIS). Ten image sets were reanonymized for assessment of intra- and interreader agreement. Agreement was calculated on lesion level by percentage exact agreement (PEA) and Cohen κ, and for sum scores by absolute agreement, single-measure intraclass correlation coefficient (ICC).Results.WBMRI of the spine and peripheral joints and entheses generally showed moderate to almost perfect interscan agreement with PEA ranging from 95% to 100%, κ 0.71–1.00, and ICC 0.95 to 1.00. Intra- and interreader data generally showed moderate to almost perfect agreement. Agreement with conventional MRI varied. More lesions were found in patients than in HC.Conclusion.WBMRI showed good interscan agreement, implying that repositioning of the patient between examinations does not markedly affect scoring of lesions. Intra- and interreader agreement were moderate to almost perfect.

Diffuse idiopathic skeletal hyperostosis (DISH) is a condition characterised by calcification and ossification of ligaments and entheses. The condition usually affects the axial skeleton, in particular, at the thoracic segment, though also other portions of the spine are often involved. DISH often involves also peripheral tendinous and/or entheseal sites either alone, or in association with the involvement of peripheral joints. At times, new bone formation involves the bone itself, but sometimes it involves joints not usually affected by osteoarthritis (OA) which result in bony enlargement of the epiphysis, joints space narrowing and a reduced range of motion. Because of the entheseal involvement, DISH can be mistaken for seronegative spondyloarthropathies or for a "simple" OA. Furthermore, other implications for the recognition of DISH include spinal fractures, difficult intubation and upper endoscopies, decreased response rates in DISH with concomitant spondyloarthritides, and increased likelihood to be affected by metabolic syndrome and cardiovascular diseases. This Atlas is intended to show the imaging finding in DISH in patients diagnosed with the condition by the Resnick classification criteria.

To evaluate the association between inflammatory back pain (IBP) features, acute and structural MRI findings suggestive of sacroiliitis, and diagnosis of spondyloarthritis (SpA). Data from 224 patients who underwent MRI for suspected sacroiliitis (2005–2015) was retrospectively reviewed by an expert rheumatologist for the presence of IBP features and for clinical standard of reference diagnosis. A telephone questionnaire was performed in cases of missing data. Acute and structural MRI parameters were scored by an experienced radiologist for the presence of sacroiliitis using the Assessment of Spondyloarthritis International Society (ASAS) criteria, Berlin score, and observer’s global impression (GI) scores. Association between IBP features and MRI scores, and odds ratio for SpA diagnosis, were calculated. One hundred ninety-three subjects were included (119 F:74 M, mean age 39.7 ± 15.6, mean follow-up 49 ± 18 months). Fifty-two (26.9%) subjects were diagnosed with SpA. IBP scores were significantly higher in SpA patients (p

STUDY DESIGN Retrospective cohort study. OBJECTIVE The aim of this study was to evaluate the role and value of whole-spine computerized tomography (WSCT) versus radiographs and targeted CT to tender spinal regions in patients with diffuse idiopathic skeletal hyperostosis (DISH) after low-energy trauma. SUMMARY OF BACKGROUND DATA Subjects with DISH are prone to spinal fractures even after low-impact trauma due to a rigid spinal structure. METHODS One-hundred forty-seven subjects (average age: 83 years, M:F 64/83) with verified DISH (Resnick and Niwayama radiographic criteria) on WSCT who were admitted to the emergency room (ER) after low-energy trauma and for whom there were radiographs of at least the thoracic and lumbar spine were evaluated for the presence of acute spinal fractures on both radiographs and WSCT. Agreement between fracture location and spinal tenderness location (cervical, thoracic, or lumbar) as reported in the medical record was evaluated. RESULTS Significantly more acute fractures were detected on WSCT compared to radiographs (55 and 32, P

Sacroiliitis, inflammation of the sacroiliac joint (SIJ), may be associated with many rheumatic and nonrheumatic disorders. The diagnosis of sacroiliitis may be difficult in many patients, and awareness of its typical manifestations along with recognition of its diverse presentations and cognizance of the limitations of today's imaging modalities are critical to good clinical practice. This review presents the didactic approach to the early diagnosis of sacroiliitis in patients with suspected axial spondyloarthritis and other nosologic entities, discussing also differential interpretation of information acquired from patients' histories, physical examination, and imaging.

Objective To review the strengths, limitations, and new insights in the anatomy and magnetic resonance imaging (MRI) features of active and structural lesions of sacroiliitis in spondyloarthritis. Discussion MRI plays a key role in the diagnosis and follow-up of sacroiliitis in spondyloarthritis. MRI of the sacroiliac joints in affected patients may show active lesions such as bone marrow edema, capsulitis, enthesitis, or synovitis as well as structural changes such as erosion, fat infiltration, sclerosis, backfill, and ankylosis. Active lesions of sacroiliitis on MRI are particularly important for the diagnosis and assessment of ongoing active inflammation. Structural lesions increasingly gain importance for diagnosis and follow-up. Conclusion Active lesions remain the hallmark for assessment of inflammation in sacroiliitis. Structural lesions increasingly play a role in the diagnosis of spondyloarthritis.

Anterior chest wall (ACW) inflammation is not an uncommon finding in patients with axial spondyloarthritis (ax-SpA) and reportedly occurs in 26% of these patients. Radiologists may only be familiar with spinal and peripheral joint imaging, possibly due to the inherent challenges of ACW imaging on some cross-sectional imaging modalities. Knowledge of relevant joint anatomy and the location of sites of inflammation allows the interpreting radiologist to better plan appropriate imaging tests and imaging planes. Accurate assessment of disease burden, sometimes in the absence of clinical findings, may alert the treating rheumatologist, allowing a better estimation of disease burden, increased accuracy of potential imaging scoring systems, and optimize assessment and response to treatment. This article reviews salient anatomy and various imaging modalities to optimize diagnosis, important differential diagnoses, and the interpretation of ACW imaging findings in ax-SpA.

Both the fields of rheumatology and radiology are changing rapidly. Effective medication has become available for rheumatoid arthritis (RA) and transformed it from a progressive disabling disease into a chronic disease. Indications for magnetic resonance imaging (MRI) have changed accordingly, shifting toward early detection. There is also an overall increased clinical demand for high-end imaging. Together with improvement of MRI units and sequences, MRI protocols are adapted based on clinical indications. This article addresses (1) the clinical background and present role of MRI in early disease detection, (2) RA involvement of peripheral joints, (3) RA involvement of the spine, and (4) state-of-the-art RA MRI protocols. The key toward cost-effective MRI examination in RA is communication between radiologist and rheumatologist as well as awareness and knowledge of the basics and advancements in both fields.

Background:Inflammation in peripheral joints and entheses is common in spondyloarthritis (SpA). Whole-body magnetic resonance imaging (WB-MRI) allows assessment of the overall inflammatory status of arthritis patients including joints and entheses. The OMERACT MRI Whole-body scoring system for Inflammation in Peripheral joints and Entheses (MRI-WIPE) [1] has been developed and validated for the entire body assessment, including the knee, but not separately validated for the knee joint region. Detailed MRI scoring systems exist for heels, hands and feet, but although knee arthritis is a key cause of functional impairment, no detailed scoring system has been validated for inflammatory arthritides. The Knee Inflammation MRI Scoring System (KIMRISS) [2] was developed and validated in osteoarthritis and demonstrated good reliability.Objectives:To perform region-based development of whole-body MRI through validation of two knee region scoring systems in SpA.Methods:Assessment of inflammation was performed in the knee region on sagittal WB-MRIs using 2 scoring systems, MRI-WIPE and KIMRISS (Figure 1), in 4 iterative multi-reader exercises. In the final exercise, images (psoriatic arthritis, axial and peripheral SpA) were obtained before and after TNF-inhibitor.Results:In the final exercise (exercise 4), reliability was mostly good for experienced readers with the overall highest interreader agreement in the previous exercise (exercise 3). Median pairwise single measure intraclass correlation coefficients for osteitis and synovitis/effusion for status/change were 0.71/0.48 (WIPE osteitis), 0.48/0.77 (WIPE synovitis/effusion), 0.59/0.91 (KIMRISS osteitis) and 0.92/0.97 (KIMRISS synovitis/effusion) (Table 1). Wilcoxon signed-rank test showed significant change in synovitis/effusion for both methods and they correlated significantly regarding status in osteitis (0.92, pTable 1.MRI-WIPE knee and KIMRISS interreader reliability for OMERACT exercises 3 and 4MRI-WIPE KneeKIMRISSOsteitisSynovitis/effusionOsteitisSynovitis/effusionVariablesNo. patientsType of scoreMean scoreICCMean scoreICCMean scoreICCMean scoreICCExercise 39 readers11Status3.6 (0-16)0.57 (-0.06-0.98)1.8 (0-4)0.47 (0.05-0.85)32.3 (1-224)0.87 (0.66-0.99)29.9 (11-60)0.34 (-0.62-0.87)11Change1.1 (-2-6)0.53 (0.03-0.90)0 (-2-1)0.32 (-0.13-0.76)27.7 (-9-131)0.58 (-0.30-0.96)-1.6 (-33-11)0.48 (-0.32-0.95)Exercise 33 readers11Status3.1 (0-16)0.83 (0.71-0.97)2.5 (0-5)0.59 (0.51-0.71)34.4 (0-233)0.89 (0.83-0.99)36.5 (16-78)0.59 (0.08-0.86)11Change0.9 (-3-6)0.72 (0.57-0.83)0 (-2-1)0.63 (0.49-0.76)19.3 (-23-86)0.46 (0.18-0.83)-1.8 (-45-17)0.89 (0.82-0.95)Exercise 49 readers10Change-0.25 (-4-5)0.38 (-0.35-0.94)-1.0 (-3-1)0.30 (-0.43-0.89)-0.45 (-37-65)0.26 (-0.86-0.97)-14.7 (-48-0.20)0.48 (-0.39-0.99)20Status2.9 (0-7)0.50 (-0.01-0.84)2.1 (0-4)0.44 (-0.21-0.79)15.2 (0-66)0.35 (-0.04-0.89)55.6 (1-122)0.54 (0.01-0.96)Exercise 43 readers10Change0.2 (-2-6)0.48 (0.16-0.66)-1.4 (-5-0)0.77 (0.70-0.82)5.8 (-27-111)0.92 (0.90-0.94)-20.7 (-65-28)0.97 (0.96-0.98)20Status2.3 (0-6)0.71 (0.60-0.80)2.7 (0-5)0.48 (0.42-0.57)11.4 (0-36)0.59 (0.39-0.71)69.4 (1-153)0.91 (0.87-0.93)Sum scores are mean (range) of the patients scores. ICC values are mean (range). ICC is 2-way mixed model, single measure, by absolute agreement.Conclusion:MRI-WIPE and KIMRISS may both be useful as part of modular whole-body evaluation in clinical studies.References:[1]Krabbe S et al. J Rheum. 2019;46(9):1215-21[2]Jaremko JL et al. RMD Open. 2017;3(1):e000355Acknowledgements:We thank CARE Aarthritis Limited (carearthritis.com) for help with setting up the web-based scoring interface, the scoring exercises, and the web-based meetings. We thank all who participated in the SIG (Special Interest Group) virtual OMERACT meeting 29 October 2020. HMO, GDM and PGC are supported in part by the National Institute for Health Research (NIHR) Leeds Biomedical Research Centre, United Kingdom. The views expressed in this study are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.Disclosure of Interests:Marie Wetterslev: None declared, Walter P Maksymowych Speakers bureau: AbbVie, Janssen, Novartis, Pfizer and UCB, Consultant of: AbbVie, Boehringer Ingelheim, Celgene, Eli Lilly, Galapagos, Janssen, Novartis, Pfizer and UCB, Grant/research support from: AbbVie, Novartis, Pfizer and UCB, Robert G Lambert Consultant of: Parexel and Pfizer, Iris Eshed: None declared, Susanne Juhl Pedersen Speakers bureau: MSD, Pfizer, AbbVie, Novartis and UCB, Consultant of: AbbVie and Novartis, Grant/research support from: AbbVie, MSD, and Novartis, Maria Stoenoiu: None declared, Simon Krabbe: None declared, Paul Bird Speakers bureau: Janssen, Abbvie, UCB, Celgene, BMS, Novartis, Pfizer, Gilead, Eli-Lilly, Consultant of: Janssen, Abbvie, UCB, Celgene, BMS, Novartis, Pfizer, Gilead, Eli-Lilly, Violaine Foltz: None declared, Ashish Jacob Mathew: None declared, Frederique Gandjbakhch: None declared, Joel Paschke: None declared, Philippe Carron Speakers bureau: Pfizer, MSD, Novartis, BMS, AbbVie, UCB, Eli Lilly, Gilead and Celgene, Consultant of: Pfizer, MSD, Novartis, BMS, AbbVie, UCB, Eli Lilly, Gilead and Celgene, Grant/research support from: UCB, MSD and Pfizer, Gabriele De Marco: None declared, Helena Marzo-Ortega Speakers bureau: AbbVie, Celgene, Janssen, Lilly, Novartis, Pfizer, Takeda and UCB, Grant/research support from: Janssen and Novartis, Anna Enevold Fløistrup Poulsen: None declared, Jacob L Jaremko: None declared, Philip G Conaghan Speakers bureau: AbbVie, AstraZeneca, BMS, Eli Lilly, EMD Serono, Flexion Therapeutics, Galapagos, Gilead, Novartis, Pfizer and Stryker, Consultant of: AbbVie, AstraZeneca, BMS, Eli Lilly, EMD Serono, Flexion Therapeutics, Galapagos, Gilead, Novartis, Pfizer and Stryker, Mikkel Østergaard Speakers bureau: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli-Lilly, Hospira, Janssen, Merck, Novartis, Pfizer, Regeneron, Roche, Sandoz, Sanofi and UCB, Consultant of: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli-Lilly, Hospira, Janssen, Merck, Novartis, Pfizer, Regeneron, Roche, Sandoz, Sanofi and UCB, Grant/research support from: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli-Lilly, Hospira, Janssen, Merck, Novartis, Pfizer, Regeneron, Roche, Sandoz, Sanofi and UCB

Objective.The Outcome Measures in Rheumatology (OMERACT) Rheumatoid Arthritis (RA) Magnetic Resonance Imaging (MRI) scoring system (RAMRIS), evaluating bone erosion, bone marrow edema/osteitis, and synovitis, was introduced in 2002, and is now the standard method of objectively quantifying inflammation and damage by MRI in RA trials. The objective of this paper was to identify subsequent advances and based on them, to provide updated recommendations for the RAMRIS.Methods.MRI studies relevant for RAMRIS and technical and scientific advances were analyzed by the OMERACT MRI in Arthritis Working Group, which used these data to provide updated considerations on image acquisition, RAMRIS definitions, and scoring systems for the original and new RA pathologies. Further, a research agenda was outlined.Results.Since 2002, longitudinal studies and clinical trials have documented RAMRIS variables to have face, construct, and criterion validity; high reliability and sensitivity to change; and the ability to discriminate between therapies. This has enabled RAMRIS to demonstrate inhibition of structural damage progression with fewer patients and shorter followup times than has been possible with conventional radiography. Technical improvements, including higher field strengths and improved pulse sequences, allow higher image resolution and contrast-to-noise ratio. These have facilitated development and validation of scoring methods of new pathologies: joint space narrowing and tenosynovitis. These have high reproducibility and moderate sensitivity to change, and can be added to RAMRIS. Combined scores of inflammation or joint damage may increase sensitivity to change and discriminative power. However, this requires further research.Conclusion.Updated 2016 RAMRIS recommendations and a research agenda were developed.

Objective To evaluate the prevalence of sacroiliitis, the radiographic hallmark of inflammatory spondyloarthropathy, among patients diagnosed with fibromyalgia syndrome (FMS), using the current Assessment of SpondyloArthritis International Society (ASAS) criteria and magnetic resonance imaging. Methods Patients experiencing FMS (American College of Rheumatology 1990 criteria) were interviewed regarding the presence of spondyloarthritis (SpA) features and underwent HLA–B27 testing, C-reactive protein (CRP) level measurement, and magnetic resonance imaging examinations of the sacroiliac joints. FMS severity was assessed by the Fibromyalgia Impact Questionnaire and the Short Form 36 health survey. SpA severity was assessed by the Bath Ankylosing Spondylitis Disease Activity Index. Results Sacroiliitis was demonstrated among 8 patients (8.1%) and ASAS criteria for diagnosis of axial SpA were met in 10 patients (10.2%). Imaging changes suggestive of inflammatory involvement (e.g., erosions and subchondral sclerosis) were demonstrated in 15 patients (17%) and 22 patients (25%), respectively. The diagnosis of axial SpA was positively correlated with increased CRP level and with physical role limitation at recruitment. Conclusion Imaging changes suggestive of axial SpA were common among patients with a diagnosis of FMS. These findings suggest that FMS may mask an underlying axial SpA, a diagnosis with important therapeutic implications. Physicians involved in the management of FMS should remain vigilant to the possibility of underlying inflammatory disorders and actively search for such comorbidities.

Diffuse idiopathic skeletal hyperostosis (DISH) is a non-inflammatory condition that involves calcification and ossification of the spinal ligaments and entheses. While, characteristic magnetic resonance imaging (MRI) lesions of the spine in patients with axial spondyloarthritis, another enthesitis-related disease, have been described and defined, there is a paucity of information regarding the MRI findings in DISH. The aim of this study was to describe the MRI findings of patients with DISH. We collected computed tomography studies with findings characteristic of DISH and that also had corresponding and concurrent MRI studies of the spine. For each patient, sagittal T1-weighted and STIR MRI sequences were evaluated for anterior/posterior vertebral corners of bone marrow edema (BME) and fat deposition. In total, we assessed 156 vertebral units in 10 patients that had both radiographic evidence of DISH and available MRI studies of the spine. Lesions consistent with BME corners were detected in five patients, and in three of them, three separate sites were involved, a finding that is suggestive of axial spondyloarthritis (SpA) according to the ASAS/OMERACT consensus statement. Fat deposition corners were detected in eight patients and in seven of them, several sites were involved. Spinal MRI lesions that are characteristic of axial SpA were commonly observed in a cohort of patients with DISH. This bears relevance to cases with diagnostic uncertainty and may imply overlapping pathogenetic mechanisms for new bone formation in both SpA and DISH. Further study is indicated to better characterize the similarities and differences between the MRI lesions of DISH and SpA.

Objective: To compare joint inflammation seen by whole-body magnetic resonance imaging (WBMRI), with “whole-body” ultrasound and clinical assessments, in patients with active rheumatoid arthritis (RA) before and during tumor necrosis factor-inhibitor (TNF-I, adalimumab) treatment. Methods: In 18 patients with RA, clinical assessment for joint tenderness and swelling, WBMRI, and ultrasound were obtained at baseline and week 16. Wrist, metacarpophalangeal (MCP) and proximal interphalangeal (PIP), elbow (except for WBMRI), shoulder, knee, ankle, and metatarsophalangeal joints were examined. Joint inflammation was defined by WBMRI as the presence of synovitis and/or osteitis and by ultrasound as gray-scale synovial hypertrophy grade >2 and/or color Doppler grade >1. On patient level, agreement was assessed by Spearman correlation coefficients (rho) for sum scores for 28 joints (i.e., wrists, MCPs, PIPs, elbows, shoulders, and knees) between clinical examination (DAS28CRP), ultrasound (US28), and WBMRI (WBMRI26; elbows not included). On joint level, agreement on inflammation between WBMRI, ultrasound, and clinical findings was calculated with Cohen's kappa (κ). Results: At patient level, WBMRI26 and US28 sum scores showed good correlation (rho = 0.72; p < 0.01) at baseline, but not at follow-up (rho = 0.25; p = 0.41). At joint level, moderate agreement was seen for hand joints (κ = 0.41–0.44); for other joints κ

The elderly population are affected by various rheumatic and inflammatory-based or related diseases, some of which appear predominantly but not exclusively in the aged population and others are unique to geriatric patients.

Spondyloarthritis (SpA), a group of inflammatory diseases of which ankylosing spondylitis is the prototype, typically presents with inflammation of the sacroiliac joints (SIJ), or sacroiliitis1,2. The article by Ziegeler, et al in this issue of The Journal 3 describes the prevalence of periarticular sacroiliitis-like structural magnetic resonance imaging (MRI) changes of a patient population with low back pain and clinically suspected sacroiliitis. The authors’ main results provide important new insights into the MRI distribution pattern of periarticular fat metaplasia of the SIJ across different age groups in nonrheumatic subjects and numerous specific pathologic conditions. To date, MRI is considered the most sensitive and specific imaging modality for diagnosing and evaluating SIJ inflammation in patients with early disease4. The introduction of biological drugs such as the tumor necrosis factor-α receptor blocker group and their beneficial effect on SpA resulted in an accelerated use of MRI for early detection of sacroiliitis4,5. As a result, an increasing number of SIJ MRI are performed each year on patients with suspected sacroiliitis6. The main acute inflammatory finding detected on MRI, but not on radiographs, is periarticular bone marrow edema, or osteitis. Structural changes such as erosions, sclerosis, and ankylosis can be seen on pelvic radiographs and computed tomography in advanced, already established disease. However, like osteitis, periarticular fatty replacement, or fat metaplasia, is not seen on radiographs and can be reliably detected only on MRI. The Assessment of SpondyloArthritis international Society (ASAS) classification system for axial SpA (axSpA) is based on whether patients meet clinical or imaging criteria5, … Address correspondence to Prof. I. Eshed, Department of Diagnostic Imaging, Sheba Medical Center, Tel Hashomer 52621, Israel. E-mail: iriseshed{at}gmail.com

Objectives To investigate criteria for treatment response and remission in patients with axial SpA as assessed by whole-body magnetic resonance imaging (WB-MRI) of axial and peripheral joints and entheses during treatment with golimumab. Methods We performed an investigator-initiated cohort study of 53 patients who underwent WB-MRI at weeks 0, 4, 16 and 52 after initiation of golimumab. Images were assessed according to the Spondyloarthritis Research Consortium of Canada MRI SI joint inflammation index, Canada–Denmark MRI spine inflammation score and the MRI peripheral joints and entheses inflammation index. Results At weeks 4, 16 and 52, WB-MRI demonstrated an at least 50% reduction of MRI inflammation of the sacroiliac joints in 16, 29 and 32 (30%, 55% and 60%) patients, of the spine in 20, 30 and 31 (38%, 57% and 58%) patients and of peripheral joints and entheses in 8, 17 and 15 (15%, 32% and 28%) patients, respectively. The BASDAI50 response was achieved by 29, 31 and 31 (55%, 58% and 58%) patients, while ASDAS clinically important improvement (ASDAS-CII) was achieved by 37, 40 and 34 (70%, 75% and 64%) patients. WB-MRI remission criteria for spine, sacroiliac joints and peripheral joints and entheses were explored; total WB-MRI remission was attained by 2, 6 and 3 (4%, 11% and 6%) patients. At week 16, among 35 patients with an at least 50% reduction in the MRI Axial Inflammation Index (sacroiliac joint and spine inflammation), 29 (83%) achieved BASDAI50 and 35 (100%) achieved ASDAS-CII; among 16 patients with MRI axial inflammation non-response, 14 (88%) were BASDAI50 non-responders and 11 (69%) did not achieve ASDAS-CII. Conclusion WB-MRI demonstrated a significant reduction of inflammation in both the spine, sacroiliac joints and peripheral joints and entheses during golimumab treatment. Few patients achieved total WB-MRI remission. Combining spinal and sacroiliac joint inflammation in an MRI Axial Inflammation Index increased the ability to capture response. Trial registration ClinicalTrials.gov, http://clinicaltrials.gov, NCT02011386.

Objective.To assess the longitudinal reliability of the Outcome Measures in Rheumatology (OMERACT) Thumb base Osteoarthritis Magnetic resonance imaging (MRI) Scoring system (TOMS).Methods.Paired MRI of patients with hand osteoarthritis were scored in 2 exercises (6-mo and 2-yr followup) for synovitis, subchondral bone defects (SBD), osteophytes, cartilage assessment, bone marrow lesions (BML), and subluxation. Interreader reliability of delta scores was assessed.Results.Little change occurred. Average-measure intraclass correlation coefficients were good-excellent (≥ 0.71), except synovitis (0.55–0.83) and carpometacarpal-1 osteophytes/cartilage assessment (0.47/0.39). Percentage exact/close agreement was 52–92%/68–100%, except BML in 2 years (28%/64–76%). Smallest detectable change was below the scoring increment, except in SBD and BML.Conclusion.TOMS longitudinal reliability was moderate-good. Limited change hampered assessment.

Axial spondyloarthritis (axSpA) is a chronic inflammatory condition that encompasses ankylosing spondylitis as well as nonradiographic axSpA and can lead to chronic pain, structural damage, and disability. The disease is strongly associated with the presence of human leukocyte antigen-B27. Early diagnosis of axSpA is significant due to new treatment regimens leading to reduction of inflammation and potentially delaying disease progression. Imaging of the sacroiliac joints and the spine plays an important role in the early diagnosis of spondyloarthritis. In the current review, the top-ten tips for the effective imaging of axSpA are presented to help both radiologists and rheumatologists in using imaging properly and effectively in their clinical practice.

To assess the presence, prevalence and characteristics of post-traumatic, inflammatory-like changes of the sacroiliac joint (SIJ) on pelvic computed tomography (CT).Sequential CT examinations from the acute (index) and follow-up post-traumatic periods of 24 patients that underwent pelvic trauma with SIJ involvement were evaluated and compared to 32 control patients with pelvic fractures that did not involve the SIJs. Index CT was evaluated for the presence of fracture, intra-articular step, and diastasis, whereas follow-up CT was scored for periarticular sclerosis, erosions, ankylosis, and backfill. Clinical follow-up was performed by pain provocation SIJ tests and a questionnaire (study representative subgroup, n=11, 46%) and from clinical files (control group, n=26, 31%). Pearson correlation coefficient was assessed between the index and follow-up CT variables. Linear regression was used to predict the influence of trauma variables on the development of inflammatory-like structural changes.Total "structural, arthritis-like lesions' score from the follow-up CT examination was significantly higher in the study compared to the control group (3.25 versus 0.05 respectively, p0.001). The presence of intra-articular diastasis and fracture were significant risk factors for the development of structural inflammatory-like lesions in the SIJ (1.19 and 2.1 respectively, p0.001). Painful SIJs by physical examination were found in 50% of the clinically evaluated subgroup which was mechanical by nature in 81.8%.Traumatic SIJ fracture or diastasis is associated with the development of post-traumatic SIJ structural inflammatory-like lesions on pelvic CT, mimicking sacroiliitis. These findings may be the result of focal, post-traumatic joint inflammation, which leads to mechanical rather than inflammatory symptoms.

To evaluate and characterize anterior chest wall (ACW) joint’s enthesopathy on CT scans in patients with DISH compared with age- and gender-matched control group. Retrospective evaluation for enthesopathy features of ACW joints—sterno-clavicular (SCJ), manubrio-sternal (MSJ), costo-sternal 1–7 (CSJ)—on chest CT scans of subjects with DISH (Resnick criteria) and of age- and gender-matched control subjects was performed. 183 subjects (DISH: 92, control: 91); male:female: 126:57, average age: 71.7 years (range 50–94) were evaluated. Total enthesopathy scores per subjects and per each joint were compared. Total enthesopathy score of ACW joints was significantly higher among DISH compared to controls (64.03 ± 15.1, 50.47 ± 12.4, p

Background Whole-body MRI (WBMRI) is a promising tool for monitoring disease activity in inflammatory joint diseases. Earlier studies have shown good correlation with conventional MRI and scoring systems for WBMRI have been developed [1,2]. However, the validation of WBMRI is limited; no studies have evaluated the agreement between repeated scans (interscan agreement) and only few studies have evaluated the intra- and interreader agreement. Objectives To validate WBMRI by evaluating the interscan agreement in patients with psoriatic arthritis (PsA), rheumatoid arthritis (RA) and healthy controls (HC) and to evaluate the intra- and interreader agreement and determine the distribution of pathologies in the subjects. Methods WBMRI was performed twice with a one-week interval in 14 patients with PsA, 10 with RA and 16 HC. Coronal images of shoulders, hips, hands and ankles/feet, and sagittal images of knees, ankles, feet and spine were obtained (STIR and pre- and post-contrast T1 weighted spin echo images). Images were anonymized and read in pairs with unknown chronological order by experienced readers (peripheral: IE; spine: SK). WBMRI was scored for 83 peripheral joints and for 33 peripheral entheses according to the OMERACT WBMRI scoring system [1], and according to the CanDen MRI spine scoring system [2]. Ten image sets were re-anonymized for assessment of intra- and interreader agreement (peripheral and spine: MO). Agreement was calculated on lesion level by percentage exact agreement (PEA) and Cohen’s kappa with squared weights, and for sum scores by absolute agreement single-measure intraclass correlation coefficient (ICC). Results The age in the PsA/RA/HC was median (range) 48(31-68)/49(26-58)/35(23-54) years and the symptom duration 10(0-24)/7(3-24)/NA years. WBMRI of the spine and peripheral joints and entheses generally showed moderate to almost perfect interscan agreement with a PEA ranging from 95-100%, kappa ranging from 0.71-1.00 and ICC ranging from 0.95-1.00 (Table 1). Intra- and interreader agreement showed moderate to almost perfect agreement with few exceptions (Table 2). More lesions were found in patients than HC. PsA patients had more lesions in acromioclavicular and sternoclavicular joints, whereas RA patients had more hand lesions (Figure 1). PsA patients had more lesions in the spine (Figure 2). Conclusion WBMRI of the spine and peripheral joints and entheses showed very good interscan agreement, implying that repositioning between examinations does not markedly affect scoring of lesions. Intra- and interreader agreement showed moderate to almost perfect agreement. The distribution of findings in PsA, RA and HC was determined. References [1] Krabbe, et al., J Rheumatol, 2019 (in press) [2] Krabbe, et al., RMD Open, 2018;4;e000624. Disclosure of Interests Anna Enevold Floeistrup Poulsen: None declared, Mette Bjoerndal Axelsen: None declared, Rene Panduro Poggenborg: None declared, Iris Eshed: None declared, Simon Krabbe: None declared, Daniel Glinatsi: None declared, Jakob Mollenbach Moller: None declared, Mikkel Ǿstergaard Grant/research support from: Abbvie, Celgene, Centocor, Merck, Novartis, Consultant for: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, and UCB, Speakers bureau: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, and UCB

Background Follow up of the ASAS Classification Cohort (CC) indicated a high positive predictive value for the ASAS classification criteria derived from baseline patient and imaging data1. Moreover, diagnosis of axSpA was changed by the rheumatologist in only 11.2% of patients after 4.4 years. This has raised potential concerns regarding diagnostic ascertainment bias. Objectives To determine the evolution of MRI features of axSpA in ASAS-CC cases by central readers, whether this reflects diagnostic assignment by the rheumatologist, and the predictive utility of baseline MRI features of axSpA. Methods MR images were available from 108 cases in the ASAS-CC at baseline and follow up (mean 4.4 years) and also had a rheumatologist diagnosis at both time points. Eight readers from the ASAS MRI group recorded MRI lesions that comprised global assessment (MRI indicative of axSpA (yes/no), active and/or structural lesion typical of axSpA (yes/no) according to ASAS definitions), ASAS definition of positive MRI, and detailed scoring of lesions per SIJ quadrant (SPARCC SIJ method). MRI data from ≥2 readers and from the majority of readers (≥5/8) was used to calculate positive and negative predictive values (PPV, NPV). Results MRI was considered diagnostic of axSpA in 52/108 (48.1%) cases at baseline and in 47/86 (54.7%) diagnosed at baseline as axSpA by the rheumatologist. Change in MRI diagnosis was recorded in 10/108 (9.3%) of cases (2 from yes to no, and 4 from no to yes for axSpA) according to agreement by ≥2 readers and in only 3 cases according to ≥5/8 readers (Table 1). Change in rheumatologist diagnosis was recorded in 9/108 (8.3%), 2 of which had a change in MRI diagnosis. Baseline MRI lesions considered typical of axSpA had very high PPV for follow up diagnosis of axSpA (Table 2). Conclusion The infrequent change in diagnostic ascertainment of rheumatologists over follow up of the ASAS-CC is supported by this central reader evaluation of MRI scans. A positive MRI at baseline had very high PPV for a follow up diagnosis of axSpA. Reference [1] Sepriano et al. ARD 2016;75:1034-42 Disclosure of Interests Walter P Maksymowych Grant/research support from: AbbVie, Pfizer, Janssen, Novartis, Consultant for: AbbVie, Eli Lilly, Boehringer, Galapagos, Janssen, Novartis, Pfizer and UCB Pharma; Chief Medical Officer for Canadian Research and Education Arthritis, Xenofon Baraliakos Grant/research support from: AbbVie, Boehringer Ingelheim, Bristol-Myers Squibb, Celgene, Centocor, Chugai, Janssen, MSD, Novartis, Pfizer Inc, Roche and UCB, Grant/research support from: AbbVie, Pfizer, Merck Sharp & Dohme, UCB Pharma, Novartis, Consultant for: AbbVie, Bristol-Myers Squibb, Boehringer Ingelheim, Celgene, Chugai, Janssen Biologics, Novartis, Pfizer, UCB Pharma, Galapagos, Speakers bureau: AbbVie, Chugai, Janssen, Novartis, Pfizer, UCB Pharma, Manouk de Hooge: None declared, Iris Eshed: None declared, Susanne Juhl Pedersen: None declared, Ulrich Weber Consultant for: Abbvie, Joachim Sieper Consultant for: Abbvie, Bohringer Ingelheim, Janssen, Lilly, Merck, Mylan, Novartis, Pfizer, UCB., Speakers bureau: Abbvie, Bohringer Ingelheim, Janssen, Lilly, Merck, Mylan, Novartis, Pfizer, UCB., Stephanie Wichuk: None declared, Denis Poddubnyy Grant/research support from: AbbVie, Merck Sharp & Dohme, Novartis, Consultant for: AbbVie, Bristol-Myers Squibb, Janssen, Merck Sharp & Dohme, Novartis, Pfizer, UCB Pharma, Speakers bureau: AbbVie, Bristol-Myers Squibb, Janssen, Merck Sharp & Dohme, Novartis, Pfizer, Roche, UCB Pharma, Joel Paschke: None declared, Robert G Lambert Consultant for: Bioclinica, Parexel, Abbvie, Mikkel Ǿstergaard Grant/research support from: Abbvie, Celgene, Centocor, Merck, Novartis, Consultant for: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, and UCB, Speakers bureau: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, and UCB

The appendicular skeleton is frequently involved in patients with rheumatic diseases. Involved joints are affected by inflammation of the synovium and joint”s entheses. Imaging depicts joint derangement and generally mirrors the pathophysiology of the disease. MRI is considered the imaging modality of choice for the detection of acute joint inflammation as well as its structural sequela. Thus, MRI plays an important role in identifying, monitoring disease activity and the patient follow-up. The MRI features of inflammatory arthritis are well described, especially in the small appendicular joints of the hands and feet and include synovitis, erosions, osteitis, tenosynovitis and erosions. In the current presentation, the typical MRI properties of large joints arthritis in different rheumatic entities will be presented with special focus on the difference from inflammatory findings in smaller appendicular joints.: Disclosure of Interests: None declared

Background Whole body MRI (WBMRI) is a new promising tool for assessing synovitis in the whole body in one session, but is less validated. Ultrasound (US) is another sensitive and well-validated imaging technique that can assess the whole body in one session. Objectives To evaluate the agreement between US, WBMRI and clinical assessment of joint inflammation in rheumatoid arthritis (RA) patients on joint and patient level. Methods US, WBMRI and clinical assessment for tender joints (TJ) and swollen joints (SwJ) were performed in 19 RA patients (90% Women, median age 55 (26-73), diseases duration 5.5 years (1-42), SwJ(28) 5 (1-13), TJ(28) 7 (2-24) and DAS28-CRP 4.66 (3.48 -6.66))) fulfilling ACR 1987 criteria for RA. The 28 conventional joints, bilateral ankles and MTP 1-5 were assessed by WBMRI and US. Joint inflammation by US was graded 0-3 on both B-mode and colour Doppler (CD), and subsequently converted to +/- by defining US synovitis as B mode >2 or CD >1, and scored for individual joint. For WBMRI, joint inflammation was defined in two ways; 1) as presence of synovitis and/or osteitis, 2) as the presence of synovitis only. The total inflammatory burden was established as sum scores for the 28 conventional joints for US (US28) and for 26 joints (WBMRI26) for WMBRI - same 28 joints except elbows (due to poor image quality). The max score of a joint in US and WBMRI including osteitis was 2, while WMBRI excluding osteitis was 1. The agreement between the clinical joint assessment, US and WBMRI for joint inflammation was calculated with Cohen’s kappa (κ). The correlations between US28, WBMRI26 and DAS28-CRP were calculated by Spearman correlation coefficient (rho). Results When considering joint inflammation by WBMRI as synovitis and/or osteitis, US28 for synovitis and WBMRI26 sum scores showed good correlation rho= 0.72 (p=0.003) (Fig. 1), whereas US28 and WBMRI26 did not correlate with DAS28 CRP (rho=-0.26, p=0.28; rho=0.20, p=0.47 respectively). Moderate-good agreement was found between US and WBMRI in wrists and MCP 1, 2 and 5(κ= 0.42–0.62) but poor in other joints (κ By comparing WBMRI synovitis (excluding osteitis) with US synovitis, US28 and WBMRI26 sum scores showed weakened correlation rho= 0.46 (p=0.049) (Fig. 2), and without correlation between WBMRI26 and DAS28 CRP (rho=-0.07, p=0.78). At joint level, moderate-good agreement was found between US and WBMRI in wrists, MCP 2 and 5, and PIP 5(κ= 0.41–0.62) but poor in other joints (κ Agreement between US and clinical joint tenderness was poor (all κ Conclusion WBMRI and US sum scores of joint inflammation showed good correlation in RA patients for the overall inflammatory burden. The agreement at joint level was variable. Disclosure of Interests: Sin Ngai Ng: None declared, Mette Bjorndal Axelsen: None declared, Mikkel Ǿstergaard Grant/research support from: Abbvie, Celgene, Centocor, Merck, Novartis, Consultant for: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, and UCB, Speakers bureau: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli Lilly, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, and UCB, Iris Eshed: None declared, Merete L. Hetland Grant/research support from: BMS, MSD, AbbVie, Roche, Novartis, Biogen, Pfizer, Consultant for: Eli Lilly, Speakers bureau: Orion Pharma, Biogen, Pfizer, CellTrion, Merck, Samsung Bioepis, Jakob Mollenbach Moller: None declared, Susanne Juhl Pedersen: None declared, Lene Terslev Speakers bureau: Speakers fee from : Roche, Novartis, Pfizer, MSD, BMS, Celgene

Early diagnosis of sacroiliitis may lead to preventive treatment which can significantly improve the patient's quality of life in the long run. Oftentimes, a CT scan of the lower back or abdomen is acquired for suspected back pain. However, since the differences between a healthy and an inflamed sacroiliac joint in the early stages are subtle, the condition may be missed. We have developed a new automatic algorithm for the diagnosis and grading of sacroiliitis CT scans as incidental findings, for patients who underwent CT scanning as part of their lower back pain workout. The method is based on supervised machine and deep learning techniques. The input is a CT scan that includes the patient's pelvis. The output is a diagnosis for each sacroiliac joint. The algorithm consists of four steps: (1) computation of an initial region of interest (ROI) that includes the pelvic joints region using heuristics and a U-Net classifier; (2) refinement of the ROI to detect both sacroiliiac joints using a four-tree random forest; (3) individual sacroiliitis grading of each sacroiliiac joint in each CT slice with a custom slice CNN classifier, and; (4) sacroiliitis diagnosis and grading by combining the individual slice grades using a random forest. Experimental results on 484 sacroiliiac joints yield a binary and a 3-class case classification accuracy of 91.9% and 86%, a sensitivity of 95% and 82%, and an Area-Under-the-Curve of 0.97 and 0.57, respectively. Automatic computer-based analysis of CT scans has the potential of being a useful method for the diagnosis and grading of sacroiliitis as an incidental finding.

Objective.To investigate the distribution of whole-body magnetic resonance imaging (WB-MRI) inflammatory lesions of peripheral joints and entheses, and their response to adalimumab (ADA) treatment and agreement with clinical measures of disease activity in patients with axial spondyloarthritis (axSpA).Methods.Explorative analysis of an investigator-initiated randomized controlled trial of ADA. WB-MRI was performed at weeks 0, 6, 24, and 48. Detailed analyses of WB-MRI lesions in peripheral joints and entheses were performed, including agreement with clinical measures of disease activity.Results.WB-MRI inflammatory lesions were most frequently observed in the acromioclavicular, metatarsophalangeal, and wrist joints (> 10% of joints), and at the greater trochanter, calcaneal insertion of the Achilles tendon, and ischial tuberosity (> 15% of entheses). Inflammation resolved in ≥ 2/3 of involved sternoclavicular, metacarpophalangeal, first carpometacarpal, hip, and tarsometatarsal joints, and pubic symphyses and medial femoral condyles. In contrast, inflammation resolved in ≤ 1/6 of involved acromioclavicular joints, knee joints, and supraspinatus tendon insertions at humerus. Tenderness of joints and entheses agreed poorly with WB-MRI inflammation (κ < 0.40). Joint tenderness resolved more frequently in MRI-positive than MRI-negative joints (8/13, 62% vs 9/34, 26%) after 6 weeks of active treatment.Conclusion.Inflammatory lesions of peripheral joints and entheses in patients with predominantly axSpA, and changes therein, can be mapped using WB-MRI, and it may contribute to differentiate between inflammatory and noninflammatory joint tenderness. (Trial registration: ClinicalTrials NCT01029847).

Background:To date, the European Alliance of Associations for Rheumatology (EULAR) guidelines recommend X-ray (XR) as first line imaging in axial Spondyloarthritis (axSpA) and magnetic resonance imaging (MR) if the diagnosis cannot be established by XR and clinical features. However, much knowledge has been gained recently strengthening the applicability of MR for the detection of structural lesions and raising the question, whether XR is still necessary. Also, several publications used low-dose computed tomography (CT) as reference standard and imaging test.Objectives:In light of this complex diagnostic situation, the aim of this study was to compare the three major modalities, XR, MR and CT of SIJ, in their diagnostic performance of axSpA and differential diagnosis in a cohort of patients with low back pain using the final judgment of the rheumatologist as standard of reference.Methods:163 patients (89 with axSpA; 74 with degenerative diseases) underwent XR, CT and MR. Three blinded experts categorized the imaging into axSpA, other diseases or normal in 5 separate reading rounds (XR, CT, MR, XR+MR, CT+MR, respectively). The results were compared to the clinical diagnosis. Sensitivity and specificity values for axSpA and interrater reliability were compared.Results:XR showed lower sensitivity and specificity (66.3%/67.6% respectively) compared to MR (82.0%/86.5%) and CT (77.5%/97.3%). Sensitivity and specificity of XR+MR was similar to MR alone (77.5% / 87.8%). However, CT+MR was superior to MR alone (75.6% / 97.3%) (see Figure). CT had the best interrater reliability (kappa = 0.875) followed by MR (0.665) and XR (0.517). CR+MR reliability was similar (0.662) compared to MR alone, while CT+MR reliability (0.732) was superior.Figure 1.Frequency of positive and negative findings in radiography (XR), computed tomography (CT), magnetic resonance imaging (MR) and combinations and resulting diagnostic accuracy values. SE: Sensitivity, SP: Specificity, LR-/+: negative/positive likelihood ratio.Conclusion:In conclusion, XR is inferior to cross-sectional imaging and should be replaced by MR or CT for differential diagnosis. While MR is the most sensitive imaging technique, it lacks specificity when compared to CT. CT alone has high diagnostic accuracy, despite being insensitive to bone marrow lesions such as fatty metaplasia or osteitis. Adding CT to MR leads to an increase in specificity at a minor expense of sensitivity.References:[1]Sieper J, Rudwaleit M, Baraliakos X, et al. The Assessment of SpondyloArthritis international Society (ASAS) handbook: a guide to assess spondyloarthritis. Ann Rheum Dis. 2009;68 Suppl 2:ii1-44.[2]Mandl P, Navarro-Compán V, Terslev L, et al. EULAR recommendations for the use of imaging in the diagnosis and management of spondyloarthritis in clinical practice. Ann Rheum Dis. 2015;74(7):1327-39.[3]Diekhoff T, Hermann KA, Greese J, et al. Comparison of MRI with radiography for detecting structural lesions of the sacroiliac joint using CT as standard of reference: results from the SIMACT study. Ann Rheum Dis. 2017.[4]Diekhoff T, Greese J, Sieper J, Poddubnyy D, Hamm B, Hermann KA. Improved detection of erosions in the sacroiliac joints on MRI with volumetric interpolated breath-hold examination (VIBE): results from the SIMACT study. Ann Rheum Dis. 2018;77(11):1585-89.[5]Baraliakos X, Hoffmann F, Deng X, Wang YY, Huang F, Braun J. Detection of Erosions in Sacroiliac Joints of Patients with Axial Spondyloarthritis Using the Magnetic Resonance Imaging Volumetric Interpolated Breath-hold Examination. The Journal of rheumatology. 2019;46(11):1445-49.[6]Wu H, Zhang G, Shi L, et al. Axial Spondyloarthritis: Dual-Energy Virtual Noncalcium CT in the Detection of Bone Marrow Edema in the Sacroiliac Joints. Radiology. 2019;290(1):157-64.Disclosure of Interests:Torsten Diekhoff Speakers bureau: Canon MS, Roche, Novartis, MSD, Grant/research support from: Assessment of Spondyloarthritis International Society, Iris Eshed: None declared, Felix Radny: None declared, Katharina Ziegeler: None declared, Fabian Proft: None declared, Juliane Greese: None declared, Dominik Deppe: None declared, Robert Biesen: None declared, Kay-Geert Hermann: None declared, Denis Poddubnyy: None declared

Background:Whole-body MRI (WB-MRI) allows assessment of the overall inflammation in arthritis patients, including joint and entheses. To enhance the use of WB-MRI in clinical trials, the OMERACT MRI in Arthritis Working Group developed the OMERACT MRI Whole-body score for Inflammation in Peripheral joints and Entheses in inflammatory arthritis (MRI-WIPE) [1]. This has been validated for the entire body, including the hip/pelvis region, but not for each individual region. More detailed scoring systems exist for heels, hands and feet but although hip arthritis is a key cause of functional impairment in spondyloarthritis (SpA), no detailed scoring system has been published for use in SpA. The Hip Inflammation Magnetic Resonance Imaging Scoring System (HIMRISS) was developed and validated in osteoarthritis showing good reliability.Objectives:To validate reliability, correlation and responsiveness of two WB-MRI scores for the hip/pelvis region in SpA.Methods:Inflammation in the hip/pelvis region was assessed on coronal WB-MRIs in 4 iterative multi-reader exercises using MRI-WIPE for the hip/pelvis region and HIMRISS (Figure 1). In final exercises, images (axial/peripheral SpA and psoriatic arthritis) were obtained before and after TNF-inhibitor.Results:In final exercises reliability was mostly good for the best calibrated readers. Median single-measure intraclass correlation coefficients were 0.58-0.65 (WIPE osteitis), 0.10-0.88 (HIMRISS osteitis), 0.38-0.72/0.52-0.60 (WIPE synovitis/effusion) and 0.68-0.89/0.78-0.85 (HIMRISS synovitis/effusion) (Table 1). The methods correlated significantly for status in osteitis (0.72, p=0.019) and for synovitis/effusion status (0.83, p=0.003) and change (0.73, p=0.017) (Table 1). In exercise 4 Wilcoxon signed-rank test showed significant change in osteitis between timepoints using WIPE hip/pelvis and SRM was large (1.23), while lower for WIPE synovitis/effusion and HIMRISS.Table 1.MRI-WIPE hip/pelvis and HIMRISS interreader reliability for OMERACT exercises 3-4MRI-WIPE hip/pelvisHIMRISSOsteitisSynovitis/effusionOsteitisSynovitis/effusionVariablesNo. patients(cases)Type of scoreMeanscoreICCMeanscoreICCMeanscoreICCMeanscoreICCExercise 39 readers11Status2.3 (0-10)0.69 (0.23-0.93)1.4 (0-4)0.58 (-0.06-0.96)8.2 (1-60)0.84 (0.56-0.99)12.8 (3-25)0.52 (0.00-.91)11Change-0.2 (-1-1)NA-0.2 (-3-1)0.50 (0.10-0.87)-0.35 (-3-1)NA-1.8 (-17-10)0.50 (-0.05-0.89)Exercise 33 readers11Status1.8 (0-10)0.63 (0.46-0.93)1.7 (0-5)0.60 (0.34-0.80)6.6 (0-65)0.88 (0.77-0.94)12.8 (2-28)0.89 (0.87-0.91)11Change-0.12 (-1-1)NA-0.12 (-3-2)0.60 (0.48-0.83)-0.7 (-7-0)NA-1.6 (-21-8)0.78 (0.70-0.87)Exercise 49 readers10 (1-10)Status1.2 (0-4)0.21 (-0.39-0.91)1.1 (0-2)0.19 (-0.31-0.69)1.8 (0-6)0.07 (-0.17-0.83)16.4 (9-23)0.31 (0.00-0.89)10 (11-20)Status1.6 (0-6)0.51 (-0.08-0.99)1 (0-3)0.40 (-0.17-0.88)3.5 (1-8)0,08 (-0.21-0.95)11.2 (5-24)0.49 (0.00-0.94)10 11-20)Change-0.4 (-2-0)NA-0.39 (-2-0)0.22 (-0.68-0.83)-2.2 (-7-2)NA-5.2 (-18-0)0.57 (0.02-0.92)20 (1-20)Status1.4 (0-6)0.41 (-0.35-0.92)1.0 (0-3)0.27 (-0.07-0.75)2.7 (0-9)0.09 (-0.17-0.85)13.8 (5-25)0.45 (0.01-0.90)Exercise 43 readers10 (1-10)Status0.8 (0-4)0.29 (0.01-0.78)1.3 (0-2)-0.02 (-0.29-0.12)0.4 (0-2)-0.04 (-0.04-0.04)15.8 (5-26)0.73 (0.59-0.89)10 (11-20)Status1.8 (0-9)0.65 (0.52-0.76)1.2 (0-4)0.72 (0.62-0.81)1.7 (0-5)0.06 (-0.17-0.35)9.2 (2-26)0.68 (0.53-0.88)10 (11-20)Change-0.6 (-2-0)NA-0.5 (-3-1)0.52 (0.49-0.55)-0.2 (-2-1)NA-2.8 (-19-6)0.85 (0.82-0.88)20 (1-20)Status1.3 (0-9)0.58 (0.43-0.69)1.2 (0-4)0.38 (0.31-0.44)1.0 (0-5)0.10 (-0.09-0.33)12.5 (2-26)0.73 (0.69-0.77)Sum scores and ICCs are mean (range). ICC is 2-way mixed, single measure, by absolute agreement.Conclusion:MRI-WIPE and HIMRISS may be useful tools in modular WB-MRI evaluation of hip/pelvis inflammation in clinical trials in SpA.References:[1]Krabbe S et al. J Rheum. 2019;46(9):1215-21[2]Jaremko JL et al. J Rheum. 2019;46(9)1239-42Acknowledgements:We thank CARE Arthritis Limited (carearthritis.com) for help with setting up the web-based scoring interface, scoring exercises, and the web-based meetings. We acknowledge the contribution of SIG (Special Interest Group) participants at the virtual OMERACT meeting October 29, 2020. HMO, GDM and PGC are supported in part by the National Institute for Health Research (NIHR) Leeds Biomedical Research Centre, United Kingdom. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.Disclosure of Interests:Marie Wetterslev: None declared, Robert G Lambert Consultant of: Parexel and Pfizer, Walter P Maksymowych Speakers bureau: AbbVie, Janssen, Novartis, Pfizer and UCB, Consultant of: AbbVie, Boehringer Ingelheim, Celgene, Eli Lilly, Galapagos, Janssen, Novartis, Pfizer and UCB, Grant/research support from: AbbVie, Novartis, Pfizer and UCB, Iris Eshed: None declared, Susanne Juhl Pedersen Speakers bureau: MSD, Pfizer, AbbVie, Novartis and UCB, Consultant of: AbbVie and Novartis, Grant/research support from: AbbVie, MSD, and Novartis, Paul Bird Speakers bureau: Janssen, Abbvie, UCB, Celgene, BMS, Novartis, Pfizer, Gilead, Eli-Lilly, Consultant of: Janssen, Abbvie, UCB, Celgene, BMS, Novartis, Pfizer, Gilead, Eli-Lilly, Maria Stoenoiu: None declared, Simon Krabbe: None declared, Ashish Jacob Mathew: None declared, Violaine Foltz: None declared, Frederique Gandjbakhch: None declared, Joel Paschke: None declared, Gabriele De Marco: None declared, Helena Marzo-Ortega Speakers bureau: AbbVie, Celgene, Janssen, Lilly, Novartis, Pfizer, Takeda and UCB, Grant/research support from: Janssen and Novartis, Philippe Carron Speakers bureau: Pfizer, MSD, Novartis, BMS, AbbVie, UCB, Eli Lilly, Gilead and Celgene, Consultant of: Pfizer, MSD, Novartis, BMS, AbbVie, UCB, Eli Lilly, Gilead and Celgene, Grant/research support from: UCB, MSD and Pfizer, Anna Enevold Fløistrup Poulsen: None declared, Jacob L Jaremko: None declared, Philip G Conaghan Speakers bureau: AbbVie, BMS, Eli Lilly, Flexion Therapeutics, Galapagos, Gilead, Novartis, Pfizer, Regeneron, Stryker, Consultant of: AbbVie, BMS, Eli Lilly, Flexion Therapeutics, Galapagos, Gilead, Novartis, Pfizer, Regeneron, Stryker, Mikkel Østergaard Speakers bureau: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli-Lilly, Hospira, Janssen, Merck, Novartis, Pfizer, Regeneron, Roche, Sandoz, Sanofi and UCB, Consultant of: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli-Lilly, Hospira, Janssen, Merck, Novartis, Pfizer, Regeneron, Roche, Sandoz, Sanofi and UCB, Grant/research support from: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli-Lilly, Hospira, Janssen, Merck, Novartis, Pfizer, Regeneron, Roche, Sandoz, Sanofi and UCB

Background:The ASAS definition of a positive MRI for inflammation in the spine (ASAS-MRIspine+) is intended for classification of patients as having axSpA but is often misused for diagnostic purposes. This is problematic because bone marrow edema (BME) in the spine may occur in 20-40% of those with mechanical back disorders. The ASAS MRI group has generated updated consensus lesion definitions which have been validated on MRI spine images from the ASAS Classification Cohort.Objectives:We aimed to identify quantitative cut-offs based on numbers of vertebral corners that define ASAS-MRIspine+, there being two gold standards: A. majority central reader decision as to the presence of spine MRI findings consistent with axSpA B. rheumatologist expert opinion diagnosis of axSpA.Methods:Eight ASAS-MRI readers recorded MRI lesions in the spine according to recently updated ASAS definitions from 62 cases in an eCRF that comprises global assessment (MRI consistent with axSpA? (yes/no)), and detailed scoring of lesions for all sites in the spine. We calculated sensitivity and specificity for numbers of vertebral corners with BME where a majority of readers (≥5/8) agreed as to the presence of MRI findings consistent with axSpA. We selected cut-offs with ≥95% specificity. These cut-offs were analyzed for their predictive utility for rheumatologist diagnosis of axSpA by calculating positive and negative predictive values (PPV, NPV) and selecting cut-offs with PPV ≥95%. Both criteria were considered requirements for designation of MRI cut-offs defining ASAS-MRIspine+.Results:MRI findings consistent with axSpA were observed by majority read in 8 (20%) of 40 cases diagnosed with axSpA, and 0 (0%) of 19 cases without axSpA. Cut-offs achieving specificity of ≥95% for MRI findings consistent with axSpA were 4 vertebral corners (sensitivity 75%) for all cases, 3 vertebral corners (sensitivity 37.5%) for cases with ≥1 additional location with inflammation, 1 vertebral corner (sensitivity 62.5%) in cases with ≥2 vertebral corner fat lesions (Table 1). All of the above cut-offs also had very high PPV (≥95%) for diagnosis of axSpA in cases diagnosed by the rheumatologist (Table 2).Table 1.Majority readers agree MRI findings consistent with axSpA are present is the gold-standard external referenceMRI cut-offsSensitivity (95%CI)Specificity (95%CI)BME in ≥2 vertebral corners87.5 (47.3 - 99.7)87.0 (75.1 - 94.6)BME in ≥ 3 vertebral corners87.5 (47.3 - 99.7)94.4 (84.6 - 98.8)BME in ≥4 vertebral corners75.0 (34.9 - 96.8)98.2 (90.1 - 100.0)Cases with ≥1 additional non-corner site inflammatory lesionBME in ≥2 vertebral corners37.5 (8.5 - 75.5)94.4 (84.6 - 98.8)BME in ≥3 vertebral corners37.5 (8.5 - 75.5)98.2 (90.1-100.0)Cases with ≥2 vertebral corner fat lesionsBME in ≥1 vertebral corner62.5 (24.5 - 91.5)100.0 (93.4-100.0)BME in ≥2 vertebral corners62.5 (24.5 - 91.5)100.0 (93.4-100.0)Table 2.Predictive values of cut-offs for number of vertebral corners with BME according to the diagnostic ascertainment of the rheumatologistMRI cut-offsSensitivity (95%CI)Specificity (95%CI)PPVNPVMRI findings consistent with axSpA ≥any 2 readers52.5 (36.1 - 68.5)94.7 (74.0 - 99.9)95.5 (75.3 - 99.3)48.6 (40.2 - 57.2)MRI findings consistent with axSpA ≥majority read20.0 (9.1 - 35.6)100.0 (82.4 - 100.0)100.037.3 (33.7 - 40.9)BME in ≥ 4 vertebral corners17.5 (7.3 - 32.8100.0 (82.4 - 100.0)100.036.5 (33.3 - 39.9)Cases with ≥1 additional inflammatory lesionBME in ≥ 3 vertebral corners10.00 (2.8 - 23.7)100.00 (82.4 - 100.0)100.034.5 (32.2 - 36.9)Cases with ≥2 vertebral corner fat lesionsBME in ≥1 vertebral corner12.50 (4.2 - 26.8)100.00 (82.4 - 100.0)100.035.2 (32.6 - 37.9)Conclusion:A cut-off of BME in ≥4 vertebral corners, or ≥3 corners in the setting of additional inflammatory lesions at other locations or corner fat, are primary candidates for defining ASAS-MRIspine+. These cut-offs apply to typical patients referred to a rheumatologist with a high index of suspicion of axSpA and may not be appropriate in other populations.Disclosure of Interests:None declared

Background:Randomized controlled trials have targeted reducing the size of BML and degree of synovitis for the treatment of OA. We have developed the OMERACT Knee Inflammation MRI Scoring System (KIMRISS) and have recently refined it to maximize reliability and sensitivity to change. Innovations include electronic overlays for assessment of BML in 500 subregions, a web-based interface with direct online scoring, and real-time iterative calibration (RETIC) prior to reading exercises. Synovitis-effusion (S-E) is also scored on all consecutive sagittal slices on a web-based interface.Objectives:We aimed to test the feasibility, reliability, and responsiveness of KIMRISS versus an established method, MOAKS, in two multi-reader exercises.Methods:KIMRISS incorporates web-based graphic overlays for each of femur, tibia, and patella (range 0-500). S-E is recorded as the largest diameter perpendicular to the longest axis of this feature (range 0-100). All scores are pro-rated for a standardized number of MRI slices. In a pre-reading exercise for KIMRISS, readers scored sufficient cases in RETIC to attain scoring proficiency, pre-specified as an ICC of ≥0.80 and ≥0.70 for status and change scores of BML and S-E compared to developer reads. A new web-based scoring platform with overlays designating different subregions for scoring BML was developed for MOAKS. We compared reliability for status and change scores of BML and S-E in 2 international multi-reader exercises of baseline and one-year MRI scans from the Osteoarthritis Initiative: A. 4 expert readers and an OMERACT fellow scored 38 cases selected for MOAKS BML score ≥1. B. 7 expert readers and an OMERACT fellow scored 60 cases selected for MOAKS BML ≥3 and Kellgren-Lawrence (K-L) grade Results:For exercises A/B, subjects were 55.3%/ 26.7% male, mean(±SD) age 61.7(±9.1)/61.9(8.8) years, and radiographic K-L grade ≤2 in 39.4%/100%. Change was small in both exercises (Table 1.KIMRISS and MOAKS scores in Two International Multi-reader ExercisesMethodMRI featureScores mean (SD)SDC(% of max)P valueSRMBaselineOne-year Follow upChangeEXERCISE AMOAKSBML3.6 (2.9)3.4 (2.3)-0.2 (1.9)1.0 (2.2%)0.72-0.11Synovitis-effusion1.3 (0.8)1.5 (0.8)0.2 (0.4)0.4 (13.3%)0.0170.5KIMRISSBML15.7 (13.3)21.2 (22.5)5.5 (15.3)5.6 (1.1%)0.0220.36Synovitis-effusion21.8 (12.0)24.3 (11.9)2.5 (7.4)2.8 (2.8%)0.0430.34EXERCISE BMOAKSBML4.2 (2.6)3.7 (2.4)-0.5 (2.1)1.1 (2.4%)0.083-0.24Synovitis-effusion1.2 (0.7)1.3 (0.8)0.0 (0.5)0.4 (13.3%)0.590.0KIMRISSBML18.0 (17.5)15.9 (14.3)-2.1 (12.3)5.9 (1.2%)0.19-0.17Synovitis-effusion21.8 (9.3)22.9 (10.8)1.1 (7.1)2.2 (2.2%)0.250.15Intra-class Correlation Coefficients (95%CI)MethodMRI featureExercise AExercise BKIMRISS statusKIMRISS changeBML0.86 (0.78-0.92)0.88 (0.81-0.93)0.80 (0.70-0.87)0.72 (0.64-0.80)MOAKS statusMOAKS changeBML0.71 (0.46-0.85)0.76 (0.64-0.85)0.67 (0.56-0.77)0.69 (0.60-0.78)KIMRISS statusKIMRISS changeSynovitis-effusion0.88 (0.81-0.93)0.87 (0.79-0.92)0.75 (0.52-0.86)0.87 (0.82-0.91)MOAKS statusMOAKS changeSynovitis-effusion0.66 (0.4-0.79)0.52 (0.36-0.67)0.65 (0.52-0.75)0.48 (0.37-0.60)Conclusion:The KIMRISS method for scoring BML and Synovitis-Effusion scores highly for feasibility and demonstrates consistently high reliability when compared to MOAKS. Further validation for responsiveness is necessary in cases with greater change in MRI features than in the OAI dataset.Disclosure of Interests:None declared.

Purpose To investigate the current role of WB-MRI for rheumatic inflammatory diseases in clinical practice using a survey addressed to musculoskeletal radiologists. Methods A survey composed of 61 questions, subdivided in three sections, demographics (five questions), application of WB-MRI for inflammatory musculoskeletal diseases in adults and children (28 questions: 7 open and 21 multiple choice for each subgroup) was distributed via the European Society of Musculoskeletal Radiology (ESSR) from July 2 to December 31, 2018 to radiologists working in academic, private, and public workplaces. Comparisons among the different workplaces were performed using the Chi-squared and the Kruskal-Wallis test for nominal and ordinal data, respectively (p Results Seventy-two participants out of the 1779 (4%) members of the ESSR with 10.4 ± 7.9 years of experience in musculoskeletal imaging, replied to at least one question. 30.6% and 12.3% of the respondents performed at least 50 WB-MRI examinations per year in adults and children, respectively. The most frequent indications were myositis in adults and chronic recurrent multifocal osteomyelitis (CRMO) in children, the latter mostly in academic centers (p = 0.013). The ESSR Arthrits Subcommitte's protocol was applied by half of the participants and especially radiologists working in private practice used it for adults (p = 0.025). Contrast medium was rarely used for adults particularly by academics (p = 0.04). Diffusion Weighted Imaging was applied for children mostly in private practice (p = 0.01) although, overall, it plays a marginal role. Scoring systems were rarely used. Ongoing research is limited. Conclusion WB-MRI is not routinely applied for musculoskeletal inflammatory diseases. The most frequent indications are myositis and CRMO.

Background:Heterogeneity is a hallmark of psoriatic arthritis (PsA), which is reflected in diverse clinical, imaging and molecular features that may reflect disease course and response to treatment. We hypothesized that specific molecular pathways underlie the various manifestations of PsA.Objectives:To create a model for accurate and biologically meaningful sub-phenotyping of PsA using imaging and molecular data. Specifically, we aimed to identify imaging sub-phenotypes in patients with PsA and determine their association with whole blood mRNA expression markers.Methods:55 patients with PsA ready to initiate treatment for active disease were prospectively recruited. An ultrasound assessment of the extent of musculoskeletal inflammation in 64 joints, 34 tendons and 16 entheses was performed. Sonographic inflammation (in greyscale and Doppler) of the following domains was graded for: a) synovitis; b) peri-tendonitis; c) tenosynovitis; and d) enthesitis. A global inflammatory score was calculated for each tissue domain. Peripheral blood was profiled with RNAseq, and gene expression data were obtained. Analyses were performed in two stages: 1) Unsupervised cluster analysis was performed using hierarchial and k-means to define imaging sub-phenotypes in PsA that reflected the predominant tissue involved; 2) Principal component analysis with ellipses was used to determine the association between imaging-defined clusters and peripheral blood gene expression profile.Results:The patients could be divided into 3 groups based on unsupervised hierarchical and k-means clustering of images indicating the predominant involved tissue (Figure 1): 1) Enthesitis predominant (N=13 [24%]); 2) Peri-tendonitis predominant (N=11 [20%]); 3); Synovitis predominant (N=31 [56%]). Patients in the synovitis predominant group had more nail involvement, while those in the peri-tendonitis group had the highest number of clinically active joints (Table 1). Unsupervised clustering of gene expression data identified three clusters that partially overlapped with the imaging clustering (Figure 2). Overall, 344 genes were differentially expressed (pTable 1.Clinical Features by Imaging ClusteringVariableEnthesitis predominantcluster(N=13)Peritendonitis predominant cluster(N=11)Synovitis predominant cluster(N=31)Age (years)47 (14)49 (16)45 (20)Sex: Female8 (61.5%)5 (45.5%)15 (48.4%)PsA duration (years)1.2 (1.5)1.6 (11.5)0.8 (3.7)BMI29.4 (6.8)25 (8.1)26.1 (8.4)Nail lesions3 (23.1%)5 (45.5%)17 (54.8%)PASI1.2 (2.7)1.2 (3.2)2.8 (7.8)Tender joint count6 (9)11 (5)3 (6)Swollen joint count2 (6)10 (7)3 (6)Dactylitis3 (23.1%)4 (36.4%)7 (22.6%)Enthesitis count3 (3)1 (4)0 (2)Enthesitis12 (92.3%)7 (63.6%)15 (48.4%)hsCRP2.9 (8.8)8.5 (21.5)3.6 (9.4)Median (IQ range) and frequencies (%)Bolded=Statistically different between the 3 groups (pConclusion:We identified three different imaging clusters based on the predominant tissue involved in patients with active PsA. Distinct gene expression profiles may underlie these imaging clusters seen in PsA.Acknowledgments:The study was supported by a Discovery Grant from the National Psoriasis Foundation.Disclosure of Interests:Lihi Eder Grant/research support from: Abbvie, Lily, Janssen, Amgen, Novartis, Consultant of: Janssen, Speakers bureau: Abbvie, Lily, Janssen, Amgen, Novartis, Quan Li: None declared, Sara Rahmati: None declared, Iris Eshed: None declared, Proton Rahman Grant/research support from: Janssen and Novartis, Consultant of: Abbott, AbbVie, Amgen, BMS, Celgene, Lilly, Janssen, Novartis, and Pfizer., Speakers bureau: Abbott, AbbVie, Amgen, BMS, Celgene, Lilly, Janssen, Novartis, Pfizer, Igor Jurisica Grant/research support from: IBM, Vinod Chandran Grant/research support from: Abbvie, Celgene, Consultant of: Abbvie, Amgen, Bristol-Myers Squibb, Celgene, Eli Lily, Janssen, Novartis, Pfizer, UCB, Employee of: Spouse employed by Eli Lily

Objective.To develop and validate an enthesitis magnetic resonance imaging (MRI) scoring system for spondyloarthritis/psoriatic arthritis, using the heel as model.Methods.Consensus definitions of key pathologies and 3 heel enthesitis multireader scoring exercises were done, separated by discussion, training, and calibration.Results.Definitions for bone and soft tissue pathologies were agreed. In the final exercise, median pairwise single-measures intraclass correlation coefficients (ICC; patient-level) for entheseal inflammation status/change scores were 0.83/0.82 for all readers. For radiologists and selected rheumatologists, ICC were 0.91/0.84 and quadratic-weighted κ (lesion-level) 0.57–0.91/0.45–0.81.Conclusion.The proposed definitions and Heel Enthesitis Scoring System (HEMRIS) are reliable among trained readers and promising for clinical trials.

Juvenile spondyloarthritis may be present in at least 3 subtypes of juvenile idiopathic arthritis according to the classification of the International League of Associations for Rheumatology. By contrast with spondyloarthritis in adults, juvenile spondyloarthritis starts with inflammation of peripheral joints and entheses in the majority of children, whereas sacroiliitis and spondylitis may develop many years after the disease onset. Peripheral joint involvement makes it difficult to differentiate juvenile spondyloarthritis from other juvenile idiopathic arthritis subtypes. Sacroiliitis, and especially spondylitis, although infrequent in childhood, may manifest as low back pain. In clinical practice, radiographs of the sacroiliac joints or pelvis are performed in most of the cases even though magnetic resonance imaging offers more accurate diagnosis of sacroiliitis. Neither disease classification criteria nor imaging recommendations have taken this advantage into account in patients with juvenile spondyloarthritis. The use of magnetic resonance imaging in evaluation of children and adolescents with a clinical suspicion of sacroiliitis would improve early diagnosis, identification of inflammatory changes and treatment. In this paper, we present the imaging features of juvenile spondyloarthritis in juvenile ankylosing spondylitis, juvenile psoriatic arthritis, reactive arthritis with spondyloarthritis, and juvenile arthropathies associated with inflammatory bowel disease.

Background Patients with predominantly axial spondyloarthritis (axSpA) may also have inflammation of peripheral joints and entheses. Using a whole-body MRI (WBMRI) approach, peripheral joints and entheses can be assessed objectively and followed during treatment. Objectives To describe the localization and extent of inflammation of peripheral joints and entheses by WBMRI in patients with axSpA initiating TNF-inhibitor therapy, and to assess treatment-induced changes. Methods Fifty-three patients that fulfilled the ASAS criteria for axSpA were included. MRI of SIJs and spine and WBMRI of peripheral joints and entheses were performed at baseline and 4/16/52 weeks after starting TNF inhibitor treatment. 75 peripheral joints and 30 peripheral entheses were scored in chronological order by an experienced musculoskeletal radiologist (IE). Osteitis, synovitis and entheseal soft tissue inflammation were scored separately [0(none)/1(mild)/2(moderate/severe)]. A WBMRI peripheral joint and enthesis index (WBMRI index) was derived by summing scores of all peripheral lesions. Results Median age (IQR/range) was 35 years. (28–44/22–73); median symptom duration was 5 years. (3–13/0–31); 53% were male. Baseline median WBMRI index (n=53) was 7,4–14; 0–40 after 52 weeks (n=46) 4 (2–9; 0–26). WBMRI index decreased mean 0.6 at week 4 (p=0.17, paired t-test), 2.3 at week 16 (p In univariate analysis, WBMRI index at week 52 was associated with age (2.5 higher per 10 years increase in age, p In univariate analysis, higher age was not significantly associated with change in WBMRI index, but when adjusted for baseline WBMRI index, higher age was associated with a less prominent reduction in WBMRI index (+0.9 per 10 years increase in age). Conclusions Inflammation of peripheral joints and entheses decreased over time in a cohort of patients with predominantly axSpA. Most patients had WBMRI index above zero during follow-up, and this was related to age and involved sites prone to osteoarthritis. Thus, the WBMRI Index may capture both disease activity related to axSpA and age-related degenerative changes. Disclosure of Interest None declared