Reporting Sacroiliac Joint Imaging Performed for Known or Suspected Axial Spondyloarthritis: Assessment of SpondyloArthritis International Society Recommendations.

Whereas previous projects attempted to standardize imaging in patients with axial spondyloarthritis (axSpA), few studies have been published about the need for specific details regarding the image acquisition and lesions that may be less familiar to general radiologists. This work reports consensus recommendations developed by the Assessment of SpondyloArthritis International Society (ASAS) that aim to standardize the imaging reports in patients suspected of having or with known axSpA. A task force consisting of radiologists and rheumatologists from ASAS and one patient representative formulated two surveys that were completed by ASAS members. The results of these surveys led to the development of 10 recommendations that were endorsed by 73% (43 of 59) of ASAS members. The recommendations are targeted to the radiologist and include best practices for the inclusion of clinical information, technical details, image quality, and imaging findings in radiology reports. These recommendations also emphasize that imaging findings that indicate differential diagnoses and referral suggestions should be included in the concluding section of the radiology report. With these recommendations, ASAS aims to improve the diagnostic process and care for patients suspected of having or with known axSpA.

Detection of structural lesions of the sacroiliac joints in patients with spondyloarthritis: A comparison of T1-weighted 3D spoiled gradient echo MRI and MRI-based synthetic CT versus T1-weighted turbo spin echo MRI.

OBJECTIVES: To investigate the detection of erosion, sclerosis and ankylosis using 1 mm 3D T1-weighted spoiled gradient echo (T1w-GRE) MRI and 1 mm MRI-based synthetic CT (sCT), compared with conventional 4 mm T1w-TSE. MATERIALS AND METHODS: Prospective, cross-sectional study. Semi-coronal 4 mm T1w-TSE and axial T1w-GRE with 1.6 mm slice thickness and 0.8 mm spacing between overlapping slices were performed. The T1w-GRE images were processed into sCT images using a commercial deep learning algorithm, BoneMRI. Both were reconstructed into 1 mm semi-coronal images. T1w-TSE, T1w-GRE and sCT images were assessed independently by 3 expert and 4 non-expert readers for erosion, sclerosis and ankylosis. Cohen's kappa for inter-reader agreement, exact McNemar test for lesion frequencies and Wilcoxon signed-rank test for confidence in lesion detection were used. RESULTS: Nineteen patients with axial spondyloarthritis were evaluated. T1w-GRE increased inter-reader agreement for detecting erosion (kappa 0.42 vs 0.21 in non-experts), increased detection of erosion (57 vs 43 of 152 joint quadrants) and sclerosis (26 vs 17 of 152 joint quadrants) among experts, and increased reader confidence for scoring erosion and sclerosis. sCT increased inter-reader agreement for detecting sclerosis (kappa 0.69 vs 0.37 in experts) and ankylosis (0.71 vs 0.52 in non-experts), increased detection of sclerosis (34 vs 17 of 152 joint quadrants) and ankylosis (20 vs 13 of 76 joint halves) among experts, and increased reader confidence for scoring erosion, sclerosis and ankylosis. CONCLUSION: T1w-GRE and sCT increase sensitivity and reader confidence for the detection of erosion, sclerosis and ankylosis, compared with T1w-TSE. CLINICAL RELEVANCE STATEMENT: These methods improve the detection of sacroiliac joint structural lesions and might be a useful addition to SIJ MRI protocols both in routine clinical care and as structural outcome measures in clinical trials.

Data-driven definitions for active and structural MRI lesions in the sacroiliac joint in spondyloarthritis and their predictive utility.

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.

Novel whole-body magnetic resonance imaging response and remission criteria document diminished inflammation during golimumab treatment in axial spondyloarthritis.

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.

Quantifying bone marrow inflammatory edema in the spine and sacroiliac joints with thresholding.

BACKGROUND: Psoriatic Arthritis (PsA) is a chronic inflammatory arthritis that develops in patients with psoriasis. Inflammatory edema in the spine may reflect subclinical disease activity and be a predictor of radiographic progression. A semi-quantitative method established by the spondyloarthritis research consortium of Canada (SPARCC) is commonly used to assess the disease activity in MR images of the spine. This study aims to evaluate thresholding for quantification of subtle bone marrow inflammation in the spine and the sacroiliac (SI) joints of patients with PsA and compare it with the SPARCC scoring system. METHODS: Short tau inversion recovery (STIR) MR images of the spine (N = 85) and the SI joints (N = 95) of patients with PsA (N = 41) were analyzed. A threshold was applied to visible bone marrow in order to mask areas with higher signal intensity, which are consistent with inflammation. These areas were considered as inflammatory lesions. The volume and relative signal intensity of the lesions were calculated. Results from thresholding were compared to SPARCC scores using linear mixed-effects models. The specificity and sensitivity of thresholding were also calculated. RESULTS: A significant positive correlation between the volumes and mean relative signal intensities, which were calculated by thresholding analysis, and the SPARCC scores was detected for both spine (p < 0.001) and SI joints (p < 0.001). For the spine, thresholding had sensitivity and specificity of 83% and 76% respectively, while for the SI joints the values were 51% and 88% respectively. CONCLUSIONS: Thresholding allows quantification of subtle bone marrow inflammatory edema in patients with psoriatic arthritis, and could support SPARCC scoring of the spine. Improved image processing and inclusion of automatic segmentation are required for thresholding of STIR images to become a rapid and reliable method for quantitative measures of inflammation. TRIAL REGISTRATION: NCT02995460 (December 14, 2016) - Retrospectively registered.

Does spinal MRI add incremental diagnostic value to MRI of the sacroiliac joints alone in patients with non-radiographic axial spondyloarthritis?

OBJECTIVE: To assess the incremental diagnostic value of spine MRI evaluated separately from and combined with sacroiliac joint (SIJ) MRI in non-radiographic axial spondyloarthritis (nr-axSpA) compared with SIJ MRI alone. METHODS: The study sample comprised two independent cohorts A/B of 130 consecutive patients aged ≤50 years with back pain, newly referred to two university clinics, and 20 healthy controls. Patients were classified according to clinical examination and pelvic radiographs as having nr-axSpA (n=50), ankylosing spondylitis (n=33), or non-specific back pain (n=47). Four readers assessed SIJ and spine MRI separately 6 months apart, and 1-12 months later both scans simultaneously using standardised modules. Readers recorded presence/absence of SpA and their level of confidence in this conclusion on a 0-10 scale (0=definitely not; 10=definite). We analysed differences between SIJ MRI versus spine MRI alone, and SIJ MRI alone versus combined MRI, descriptively by the number/percentage of subjects according to the mean of four readers. RESULTS: In cohorts A/B, 15.8%/24.2% of patients with nr-axSpA having a negative SIJ MRI were reclassified as being positive for SpA by global evaluation of combined scans. However, 26.8%/11.4% of non-specific back pain controls and 17.5% of healthy volunteers with a negative SIJ MRI were falsely reclassified as having SpA by combined MRI. Low confidence in a diagnosis of SpA by SIJ MRI increased to high confidence by combined MRI in 6.6%/7.3% of patients with nr-axSpA. CONCLUSIONS: Combined spine and SIJ MRI added little incremental value compared with SIJ MRI alone for diagnosing patients with nr-axSpA and enhancing confidence in this diagnosis.

Candidate lesion-based criteria for defining a positive sacroiliac joint MRI in two cohorts of patients with axial spondyloarthritis.

OBJECTIVE: To determine candidate lesion-based criteria for a positive sacroiliac joint (SIJ) MRI based on bone marrow oedema (BMO) and/or erosion in non-radiographic axial spondyloarthritis (nr-axSpA); to compare the performance of lesion-based criteria with global evaluation by expert readers. METHODS: Two independent cohorts A/B of 69/88 consecutive patients with back pain aged ≤50 years, with median symptom duration 1.3/10.0 years, were referred for suspected SpA (A) or acute anterior uveitis plus back pain (B). Patients were classified according to rheumatologist expert opinion based on clinical examination, pelvic radiography and laboratory values as having nr-axSpA (n=51), ankylosing spondylitis (n=34) or non-specific back pain (n=72). Four blinded readers assessed SIJ MRI, recording the presence/absence of SpA by concomitant global evaluation of T1-weighted spin echo (T1SE) and short τ inversion recovery (STIR) scans and, thereafter, whether BMO and/or erosion were present/absent in each SIJ quadrant of each MRI slice. We derived candidate lesion-based criteria based on the number of SIJ quadrants with BMO and/or erosion and calculated mean sensitivity and specificity for SpA. RESULTS: For both cohorts A/B, global assessment showed high specificity (0.95/0.83) compared with the Assessment in SpondyloArthritis international Society (ASAS) definition (0.76/0.74). BMO ≥3 (0.89/0.84) or ≥4 (0.92/0.87) showed comparably high specificity to global assessment. Erosion ≥2 and/or BMO ≥3 or ≥4 were associated with comparably high sensitivity to global assessment without affecting specificity. These combined criteria showed both higher sensitivity and specificity than the ASAS definition. CONCLUSIONS: Lesion-based criteria for a positive SIJ MRI based on both BMO and/or erosion performed best for classification of axial SpA, reflecting the contextual information provided by T1SE and STIR sequences.

Identification of patient endotypes and adalimumab treatment responders in axial spondyloarthritis using blood-derived extracellular matrix biomarkers.

OBJECTIVE: To explore the potential of a panel of ECM remodelling markers as endotyping tools for axial spondyloarthritis (axSpA) by separating patients into subtypes and investigate how they differ among each other in disease activity scores and response to treatment with adalimumab. METHODS: In three axSpA studies, a panel of 14 blood-based ECM biomarkers related to formation of collagen (PRO-C2, PRO-C3, PRO-C6), degradation of collagen by metalloproteinases (C1M, C2M, T2CM, C3M, C4M, C6M, C10C), matrix metalloproteinase (MMP)-degraded prolargin (PROM), MMP-degraded and citrullinated vimentin (VICM), basement membrane turnover (PRO-C4) and neutrophil activity (CPa9-HNE) were assessed to enable patient clustering (endotyping). MASH (n=41) was a cross-sectional study, while Adalimumab in Axial Spondyloarthritis study (ASIM,n=45) and Danish Multicenter Study of Adalimumab in Spondyloarthritis (DANISH, n=49) were randomised, double-blind placebo-controlled trials of adalimumab versus placebo every other week for 6 or 12 weeks, respectively, followed by active treatment. Biomarker data were log-transformed, standardised by mean centering and scaled by the SD prior to principal component analysis and K-means clustering. RESULTS: Based on all three studies, we identified two orthogonal dimensions reflecting: (1) inflammation and neutrophil activity (driven by C1M and CPa9-HNE) and (2) collagen turnover (driven by PRO-C2). Three endotypes were identified: high inflammation endotype (Endotype1), low inflammation endotype (Endotype 2) and high collagen turnover endotype (Endotype3). Endotype1 showed higher disease activity (Ankylosing Spondylitis Disease Activity Score (ASDAS)) at baseline compared with Endotype2 and Endotype3 and higher percentage of patients responding to adalimumab based on ASDAS clinical improvement at week 24. Endotype3 showed higher percentage of patients with 50% improvement in Bath Ankylosing Spondylitis Disease Activity Index response at week 24 compared with Endotype2. CONCLUSION: These endotypes differ in their tissue remodelling profile and may in the future have utility for patient stratification and treatment tailoring.

The OMERACT whole-body MRI scoring system for inflammation in peripheral joints and entheses (WIPE) in spondyloarthritis - reference image atlas for the knee region.

OBJECTIVE: To develop a reference image atlas for the Outcome Measures in Rheumatology whole-body MRI scoring system for inflammation in peripheral joints and entheses (OMERACT MRI-WIPE) of the knee region. METHODS: Image examples of each pathology, location and grade, were collected and discussed at web-based, interactive meetings within the OMERACT MRI in Arthritis Working Group. Subsequently, reference images were selected by consensus. RESULTS: Reference images for each grade, pathology and location are depicted, along with definitions, reader rules and recommended MRI-sequences. CONCLUSION: The atlas guides scoring whole-body MRIs for inflammation in joints and entheses of the knee region according to MRI-WIPE methodology in clinical trials and cohorts.

Hip and pelvis region MRI reference image atlas for scoring inflammation in peripheral joints and entheses according to the OMERACT-MRI WIPE scoring system in patients with spondyloarthritis.

OBJECTIVE: To develop a reference image atlas for scoring the hip/pelvis region according to the OMERACT whole-body MRI scoring system for inflammation in peripheral joints and entheses (MRI-WIPE). METHODS: We collected image examples of each pathology, location and grade, discussed them at web-based, interactive meetings and, finally, selected reference images by consensus. RESULTS: Reference images for each grade and location of osteitis, synovitis and soft tissue inflammation are provided, as are definitions, reader rules and recommended MRI-sequences. CONCLUSION: A reference image atlas was created to guide scoring whole-body MRIs for arthritis and enthesitis in the hip/pelvis region in spondyloarthritis/psoriatic arthritis clinical trials and cohorts.

Comparative validation of the knee inflammation MRI scoring system and the MRI osteoarthritis knee score for semi-quantitative assessment of bone marrow lesions and synovitis-effusion in osteoarthritis: an international multi-reader exercise.

Background: Bone marrow lesions (BMLs) and synovitis on magnetic resonance imaging (MRI) are associated with symptoms and predict degeneration of articular cartilage in osteoarthritis (OA). Validated methods for their semiquantitative assessment on MRI are available, but they all have similar scoring designs and questionable sensitivity to change. New scoring methods with completely different designs need to be developed and compared to existing methods. Objectives: To compare the performance of new web-based versions of the Knee Inflammation MRI Scoring System (KIMRISS) with the MRI OA Knee Score (MOAKS) for quantification of BMLs and synovitis-effusion (S-E). Design: Retrospective follow-up cohort. Methods: We designed web-based overlays outlining regions in the knee that are scored for BML in MOAKS and KIMRISS. For KIMRISS, both BML and S-E are scored on consecutive sagittal slices. The performance of these methods was compared in an international reading exercise of 8 readers evaluating 60 pairs of scans conducted 1 year apart from cases recruited to the OA Initiative (OAI) cohort. Interobserver reliability for baseline status and baseline to 1 year change in BML and S-E was assessed by intra-class correlation coefficient (ICC) and smallest detectable change (SDC). Feasibility was assessed using the System Usability Scale (SUS). Results: Mean change in BML and S-E was minimal over 1 year. Pre-specified targets for acceptable reliability (ICC ⩾ 0.80 and ⩾ 0.70 for status and change scores, respectively) were achieved more frequently for KIMRISS for both BML and synovitis. Mean (95% CI) ICC for change in BML was 0.88 (0.83-0.92) and 0.69 (0.60-0.78) for KIMRISS and MOAKS, respectively. KIMRISS mean SUS usability score was 85.7 and at the 95th centile of ranking for usability versus a score of 55.4 and 20th centile for MOAKS. Conclusion: KIMRISS had superior performance metrics to MOAKS for quantification of BML and S-E. Both methods should be further compared in trials of new therapies for OA.

The diagnostic utility of magnetic resonance imaging in spondylarthritis: an international multicenter evaluation of one hundred eighty-seven subjects.

OBJECTIVE: To systematically assess the diagnostic utility of magnetic resonance imaging (MRI) to differentiate patients with spondylarthritis (SpA) from patients with nonspecific back pain and healthy volunteers, using a standardized evaluation of MR images of the sacroiliac joints. METHODS: Five readers blinded to the patients and diagnoses independently assessed MRI scans (T1-weighted and STIR sequences) of the sacroiliac joints obtained from 187 subjects: 75 patients with ankylosing spondylitis (AS; symptom duration ≤ 10 years), 27 patients with preradiographic inflammatory back pain (IBP; mean symptom duration 29 months), 26 patients with nonspecific back pain, and 59 healthy control subjects; all participants were age 45 years or younger. Bone marrow edema, fat infiltration, erosion, and ankylosis were recorded according to standardized definitions using an online data entry system. We calculated sensitivity, specificity, and positive and negative likelihood ratios (LRs) for the diagnosis of SpA based on global assessment of the MRI scans. RESULTS: Diagnostic utility was high for all 5 readers, both for patients with AS (sensitivity 0.90, specificity 0.97, positive LR 44.6) and for patients with preradiographic IBP (sensitivity 0.51, specificity 0.97, positive LR 26.0). Diagnostic utility based solely on detection of bone marrow edema enhanced sensitivity (67%) for patients with IBP but reduced specificity (88%); detection of erosions in addition to bone marrow edema further enhanced sensitivity (81%) without changing specificity. A single lesion of the sacroiliac joint on MRI was observed in up to 27% of control subjects. CONCLUSION: This systematic and standardized evaluation of sacroiliac joints in patients with SpA showed that MRI has much greater diagnostic utility than has been documented previously. We present for the first time a data-driven definition of MRI-visualized positivity for SpA.

The OMERACT Knee Inflammation MRI Scoring System: Validation of quantitative methodologies and tri-compartmental overlays in osteoarthritis.

OBJECTIVE: To validate a revised version of the KIMRISS method for quantification of BML and synovitis-effusion in the knee by comparison with an established method, MOAKS. METHODS: Novel calibration tools were developed for both methods. We compared reliability for status and change scores of BML and synovitis-effusion on baseline and one-year MRI scans. RESULTS: Significant increase in both BML and synovitis-effusion was evident using KIMRISS but only for synovitis-effusion using MOAKS. Pre-specified targets for acceptable reliability (≥0.80 and ≥0.70 for status and change scores, respectively) were achieved more frequently for KIMRISS for both BML and synovitis. CONCLUSION: Per OFISA criteria, KIMRISS should progress to assessment of discrimination.

Diffusion-weighted MR imaging in chronic non-bacterial osteitis: Proof-of-concept of the apparent diffusion coefficient as an outcome measure.

BACKGROUND: The apparent diffusion coefficient (ADC), as determined by whole-body diffusion-weighted MRI, may be useful as an outcome measure for monitoring response to treatment in chronic non-bacterial osteitis. PURPOSE: To test and demonstrate the feasibility of ADC-measurement methods for use as outcome measure in chronic non-bacterial osteitis. MATERIALS AND METHODS: Using data from a randomized pilot study, feasibility of change-score ADC between baseline and second MRI (ΔADC12) and third MRI (ΔADC13) as outcome measure was assessed in three settings: "whole-lesion," "single-slice per lesion," and "index-lesion per patient". Bone marrow edema lesions were depicted on short tau inversion recovery sequence at baseline and copied to ADC maps at the three time-points. Correlations between the three settings were measured as were analysis of variances. Discriminant validity was assessed as inter- and intra-observer reproducibility and smallest detectable change. RESULTS: 12 subjects were enrolled, and MRI was performed at baseline and weeks 12 and 36. Pearson correlation was high (r > 0.86; p ≤ 0.01) for ΔADC between single-slice-whole-lesion and whole-lesion-index-lesion and tended to be significant for single-slice-index-lesion settings (p = 0.06). For ΔADC12 and ΔADC13, Bland-Altman plots showed small differences (0.02, 0.03) and narrow 95% limits-of-agreement (-0.13-0.09, -0.07-0.05 µm2/s) between whole-lesion and single-slice ROI settings. Inter-observer reproducibility measured by intra-class correlation coefficient was poor-to-fair (range: 0.09-0.31), whereas intra-observer reproducibility was good-to-excellent (range: 0.67-0.90). Smallest detectable changes were between 0.21-0.28 µm2/s. CONCLUSION: ADC change-score as outcome measure was feasible, and the single-slice per lesion ROI setting performed almost equally to whole-lesion setting resulting in reduced assessment time.

Anatomic Distribution of Sacroiliac Joint Lesions on Magnetic Resonance Imaging in Patients With Axial Spondyloarthritis and Control Subjects: A Prospective Cross-Sectional Study, Including Postpartum Women, Patients With Disc Herniation, Cleaning Staff, Runners, and Healthy Individuals.

OBJECTIVE: To investigate the anatomic location and distribution of lesions on magnetic resonance imaging (MRI) in the sacroiliac (SI) joints in patients with axial spondyloarthritis (SpA), women with and without postpartum pain (childbirth within 4-16 months), patients with disc herniation, cleaning staff, runners, and healthy persons. METHODS: In a prospective cross-sectional study of 204 participants, MRI of the entire cartilaginous compartment of the SI joint was scored blindly by 2 independent, experienced readers, according to Spondyloarthritis Research Consortium of Canada definitions of SI joint inflammation and structural lesions in each SI joint quadrant or half and in each of 9 slices. The locations of the lesions (unilateral/bilateral, upper/lower, sacral/iliac, and anterior/central/posterior slices) were analyzed based on concordant reads. RESULTS: Bone marrow edema (BME) occurred in all quadrants in nearly all participant groups, but rarely bilaterally, except in patients with axial SpA and women with postpartum pain. Fat lesions were mainly found in axial SpA and occurred in all quadrants, but mostly bilaterally in sacral quadrants. Erosion was rare, except in axial SpA, where it was mainly iliac and often bilateral. Sclerosis was exclusively iliac and most frequent in women with postpartum pain. CONCLUSION: The location and distribution of common SI joint lesions in axial SpA and non-axial SpA were reported, and group-specific patterns were revealed. BME distributed bilaterally or unilaterally, both locally and more widespread in the SI joint, is common in both postpartum women with pain and axial SpA patients, which limits the use of BME to differentiate these groups. This study indicates that the presence of fat lesions, especially when widespread, and/or erosion, particularly when located centrally or posteriorly, are diagnostically important and should be investigated further.

Development and Validation of 3 Preliminary MRI Sacroiliac Joint Composite Structural Damage Scores in a 5-year Longitudinal Axial Spondyloarthritis Study.

OBJECTIVE: In axial spondyloarthritis (axSpA), sacroiliac joint (SIJ) erosion is often followed by fat metaplasia in an erosion cavity (backfill), and subsequently ankylosis. We aimed to combine the Spondyloarthritis Research Consortium of Canada (SPARCC) SIJ structural score for erosion, backfill, and ankylosis into 3 versions of a novel preliminary axSpA magnetic resonance imaging (MRI) SIJ Composite Structural Damage Score (CSDS) and to test these. METHODS: Thirty-three patients with axSpA, followed for 5 years after initiation of tumor necrosis factor inhibitor, had MRIs of the SIJs at baseline, and yearly thereafter. Three versions of CSDS were calculated based on different weightings of erosion, backfill, and ankylosis: (1) equal weighting: CSDSequal = (erosion × 0.5) + backfill + ankylosis; (2) advanced stages weighting more: CSDSstepwise = (erosion × 1) + (backfill × 4) + (ankylosis × 6); and (3) advanced stages overruling earlier stages ("hierarchical") with "<" meaning "overruled by": CSDShierarchical = (erosion × 1) < (backfill × 4) < (ankylosis × 6). RESULTS: At baseline, all CSDS correlated positively with SPARCC fat and ankylosis scores and modified New York radiography grading, and negatively with the Bath Ankylosing Spondylitis Disease Index and SPARCC SIJ inflammation scores. CSDSstepwise and CSDShierarchical (not CSDSequal) correlated positively with symptom duration and the Bath Ankylosing Spondylitis Metrology Index, and closer with SPARCC ankylosis score and modified New York radiography grading than CSDSequal. The adjusted annual progression rate for CSDSstepwise and CSDShierarchical (not CSDSequal) was higher the first year compared with fourth year (P = 0.04 and P = 0.01). Standardized response mean (baseline to Week 46) was moderate for CSDShierarchical (0.64) and CSDSstepwise (0.59) and small for CSDSequal (0.25). CONCLUSION: Particularly CSDSstepwise and CSDShierarchical showed construct validity and responsiveness, encouraging further validation in larger clinical trials. The potential clinical implication is assessment of SIJ damage progression by 1 composite score.

Utility of magnetic resonance imaging in Crohn's associated sacroiliitis: A cross-sectional study.

OBJECTIVE: Prevalence of sacroiliitis in Crohn's disease (CD) is variable depending on defining criteria. This study utilized standardized sacroiliac joint (SIJ) magnetic resonance imaging (MRI) to identify sacroiliitis in CD patients and its association with clinical and serological markers. METHODS: Consecutive adult subjects with CD prospectively enrolled from an inflammatory bowel disease clinic underwent SIJ MRI. Data collected included CD duration, history of joint/back pain, human leukocyte antigen-B27 status, Bath Ankylosing Spondylitis Metrology Index (BASMI), Bath Ankylosing Spondylitis Disease Activity Index, Harvey Bradshaw Index (HBI) for activity of CD, Ankylosing Spondylitis Disease Activity Score, and various serologic markers of inflammation. Three blinded readers reviewed MRIs for active and structural lesions according to the Spondyloarthritis Research Consortium of Canada modules. RESULTS: Thirty-three CD patients were enrolled: 76% female, 80% White, median age 36.4 years (interquartile range 27.2-49.0), moderate CD activity (mean HBI 8.8 ± SD 4.5). Nineteen subjects (58%) reported any back pain, 13 of whom had inflammatory back pain. Four subjects (12%) showed sacroiliitis using global approach and 6 (18%) met Assessment of SpondyloArthritis international Society MRI criteria of sacroiliitis. Older age (mean 51.2 ± SD 12.5 vs. 37.2 ± 14; P = .04), history of dactylitis (50.0% vs. 3.4%, P = .03) and worse BASMI (4.1 ± 0.7 vs. 2.4 ± 0.8, P ≤ .001) were associated with MRI sacroiliitis; no serologic measure was associated. CONCLUSION: There were 12%-18% of CD patients who had MRI evidence of sacroiliitis, which was not associated with back pain, CD activity or serologic measures. This data suggests that MRI is a useful modality to identify subclinical sacroiliitis in CD patients.

Joint and entheseal inflammation in the knee region in spondyloarthritis - reliability and responsiveness of two OMERACT whole-body MRI scores.

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.

Arthritis and enthesitis in the hip and pelvis region in spondyloarthritis - OMERACT validation of two whole-body MRI methods.

OBJECTIVE: To validate reliability, correlation and responsiveness of two whole-body MRI scores for the hip/pelvis region in spondyloarthritis. METHODS: Assessment of hip/pelvis inflammation in 4 multi-reader exercises using the OMERACT MRI Whole-body score for Inflammation in Peripheral joints and Entheses (MRI-WIPE) and Hip Inflammation Magnetic Resonance Imaging Scoring System (HIMRISS). RESULTS: In exercises 3-4 (11/20 cases, respectively; 9 readers) reliability was mostly good for the 3 best calibrated readers. Median pairwise single-measure ICC for status were 0.58-0.65 (WIPE-osteitis), 0.10-0.88 (HIMRISS-osteitis) and for status/change 0.38-0.72/0.52-0.60 (WIPE-synovitis/effusion) and 0.68-0.89/0.78-0.85 (HIMRISS-synovitis/effusion). SRM was 1.23 for WIPE-osteitis, while lower for WIPE-synovitis/effusion and HIMRISS. CONCLUSION: MRI-WIPE and HIMRISS may after further validation be useful in future spondyloarthritis trials.