Praveena Chiowchanwisawakit

Resolution of inflammation following treatment of ankylosing spondylitis is associated with new bone formation.

Objective. To test the hypothesis that in patients with ankylosing spondylitis (AS) a vertebral corner inflammatory lesion (CIL) visible on magnetic resonance imaging (MRI) that completely resolves following treatment with anti-tumor necrosis factor-α (TNF-α) agents is more likely to develop into a de novo syndesmophyte visible on a radiograph as compared to a vertebral corner with no CIL. Methods. Fifty patients with AS, who had MRI at baseline and at followup (mean 19.2 months), and spinal radiography at baseline and after 2 years, were followed prospectively. A persistent CIL was defined as being present on both MRI, while a resolved CIL was defined as present at baseline MRI and completely disappeared at followup MRI. Two readers read the MRI independently, and analyses were done for areas with agreement (concordant reads) and for individual reads. Results. For patients receiving anti-TNF therapy (n = 23), new syndesmophytes developed more frequently from vertebral corners where a CIL had completely resolved on followup MRI (42.9% on concordant reads) as compared to vertebral corners where no CIL was demonstrable on either the baseline or followup MRI (2.4%; p < 0.0001). Results from individual readers showed similar differences. For patients receiving standard treatment (n = 27), the same pattern, although nonsignificant, was observed (20% vs 3.3%; p = 0.16) on concordant reads, as well as on individual reads. Conclusion. Our study of AS spines documents that MRI findings predict new bone formation on radiograph. Demonstration of an increased likelihood of developing new bone following resolution of inflammation after anti-TNF therapy supports the theory that TNF-α acts as a brake on new bone formation. Because the number of new syndesmophytes was low, further study is necessary to make firm conclusions.

Fat metaplasia and backfill are key intermediaries in the development of sacroiliac joint ankylosis in patients with ankylosing spondylitis.

Fat metaplasia in bone marrow on T1‐weighted magnetic resonance imaging (MRI) scans may develop after resolution of inflammation in patients with ankylosing spondylitis (AS) and may predict new bone formation in the spine. Similar tissue, termed backfill, may also fill areas of excavated bone in the sacroiliac (SI) joints and may reflect resolution of inflammation and tissue repair at sites of erosions. The purpose of this study was to test our hypothesis that SI joint ankylosis develops following repair of erosions and that tissue characterized by fat metaplasia is a key intermediary step in this pathway.

Structural Lesions Detected by Magnetic Resonance Imaging in the Spine of Patients with Spondyloarthritis – Definitions, Assessment System, and Reference Image Set

Objective. There is no reliable and sensitive magnetic resonance imaging (MRI) assessment system for structural lesions in patients with spondyloarthritis (SpA). We sought to develop and illustrate a detailed anatomy-based set of MRI definitions and an assessment system for structural lesions in the spine of patients with SpA. Methods. MRI definitions of different structural (“chronic”) lesions at various anatomical locations in the spine, and an accompanying assessment system, were agreed by consensus within the Canada-Denmark MRI working group. Subsequently, a reference image set of representative examples of the individual pathologies, as well as borderline cases and important artefacts, were collected. Results. The defined lesions were (a) Bone erosions, subdivided into corner and non-corner vertebral body erosions and facet joint erosions; (b) Focal fat infiltration at vertebral corners; (c) Bone spurs, subdivided into corner and non-corner vertebral body spurs; and (d) Ankylosis, subdivided into corner and non-corner vertebral body ankylosis and facet joint ankylosis. All definitions were based on their appearance on sagittal T1-weighted MR images. Vertebral body structural lesions are assessed at each vertebral endplate at all 23 spinal levels from C2/3 to L5/S1, whereas facet joint lesions are to be assessed by segmental level (cervical, thoracic, and lumbar). Conclusion. An anatomy-based set of definitions and an assessment system for structural lesions in the spine of patients with SpA were developed and illustrated. The system is designed to study the spatial pattern of the lesions and their relation to spine inflammation and clinical and radiographic outcomes.

Active Inflammatory Lesions Detected by Magnetic Resonance Imaging in the Spine of Patients with Spondyloarthritis – Definitions, Assessment System, and Reference Image Set

Objective. Currently available magnetic resonance imaging (MRI) assessment systems for spine inflammation in patients with spondyloarthritis (SpA) identify only the overall inflammation in the discovertebral units. We aimed to develop and illustrate a detailed anatomy-based set of definitions and an assessment system for active inflammatory lesions in the spine of patients with SpA. Methods. MRI definitions of different inflammatory lesions at various anatomical locations in the spine, and an accompanying assessment system, were agreed by consensus within the Canada-Denmark MRI working group. Subsequently, a reference image set of representative examples of the individual pathologies, as well as borderline cases and important artefacts, were collected. Results. The defined lesions were (a) vertebral body inflammatory lesions, subdivided into corner, non-corner, massive, and lateral inflammatory lesions; and (b) vertebral inflammatory lesions not involving the vertebral body, subdivided into facet joint and other posterior element inflammatory lesions. All definitions were based on presence of increased signal intensity on sagittal T2-weighted fat-suppressed or STIR-images, as compared with the normal bone marrow signal. Vertebral body inflammatory lesions are assessed at each vertebral endplate at all 23 spinal levels from C2/3 to L5/S1, whereas facet joint or posterior element inflammatory lesions are to be assessed by segmental level (cervical, thoracic, and lumbar). Conclusion. An anatomy-based set of definitions and an assessment system for active inflammatory lesions in the spine of patients with SpA was developed and illustrated. The system is designed to study the temporal and spatial patterns of inflammation and their relation to the development of structural damage.

Development and preliminary validation of the spondyloarthritis research consortium of Canada magnetic resonance imaging sacroiliac joint structural score.

Objective. There is an unmet need for reliable assessment of structural progression in the sacroiliac joints (SIJ) of patients with spondyloarthritis (SpA), but radiography is unreliable and lacks responsiveness. We aimed to develop and validate a new scoring method for structural lesions based on magnetic resonance imaging (MRI), the Spondyloarthritis Research Consortium of Canada (SPARCC) SIJ Structural Score (SSS). Methods. The SSS method for assessment of structural lesions is based on T1-weighted spin echo MRI, validated lesion definitions, slice selection according to well-defined anatomical principles, and dichotomous scoring (lesion present/absent) of 5 consecutive slices through the cartilaginous portion of the joint. Scoring ranges are fat metaplasia (0–40), erosion (0–40), backfill (0–20), and ankylosis (0–20). We progressively conducted 3 validation exercises with 2–4 readers on baseline, and either 2-year (exercises 1 and 2) or 1-year (exercise 3) scans from 147 patients with SpA assessed blinded to timepoint. Interobserver reliability was assessed by intraclass correlation coefficient (ICC) and smallest detectable change (SDC). Results. Interobserver reliability for status score was good to excellent for ankylosis (ICC 0.79–0.98), consistently good for fat metaplasia (ICC 0.71–0.78), moderate to good for erosion (ICC 0.58–0.62), and fair to good for backfill (ICC 0.35–0.66). Reliability for change scores was moderate to good for all structural lesions despite the relatively small changes in scores, and was highest for fat metaplasia when both ICC and SDC values were compared. Conclusion. The new SPARCC MRI SSS method can detect structural changes in the SIJ with acceptable reliability over a 1–2-year timeframe, and should be further validated in patients with SpA.

Development and Validation of Web-based Training Modules for Systematic Evaluation of Active Inflammatory Lesions in the Spine and Sacroiliac Joints in Spondyloarthritis

Objective. Reliable assessment of spinal and sacroiliac joint (SIJ) inflammation on magnetic resonance imaging (MRI) is difficult. We developed 2 Web-based training modules for scoring inflammation by MRI in the spine and SIJ using the SPARCC method. These provide explicit details on methodology and define the parameters of abnormalities scored in the spine and SIJ. Our objective was to assess the influence of rigorous standardization of methodology offered by Web-based training modules on the reliability of SPARCC scores for SIJ and spinal inflammation. Methods. We studied 32 patients randomized 1:1 to either anti-tumor necrosis factor–α (anti–TNF–α) therapy or placebo for 12 weeks, with MRI examination of the SIJ and spine being conducted at baseline and 12 weeks. MRI scans (as described at www.arthritisdoctor.ca) were assessed blinded to timepoint and treatment allocation by 3 readers who had no prior experience scoring inflammation by MRI and 2 experienced SPARCC readers. The first readings by the inexperienced readers were conducted after verbal instructions on the scoring method. The second readings were conducted after formal training using the Web-based training modules. Interreader reliability was compared before and after training using the 2 SPARCC readers as “gold standard” comparators. Results. After training, a consistent improvement in reproducibility was observed, which was particularly evident for SIJ inflammation and for change scores. After completion of the training modules the inexperienced readers scored to a similar level of reproducibility as the 2 SPARCC readers. Conclusion. Systematic evaluation of SIJ and spinal inflammation by MRI can be significantly improved using Web-based training modules.

Validation of Definitions for Structural Lesions Detected by Magnetic Resonance Imaging in the Spine of Patients with Spondyloarthritis

Objective. Assessment of structural features of spondyloarthritis (SpA) on magnetic resonance imaging (MRI) has proven to be no more reliable than plain radiography, which may reflect a lack of standardization and application of rigorous definitions. The Canada-Denmark MRI Working Group has developed a comprehensive list of definitions for the structural MRI changes in the spine of patients with SpA. We conducted a systematic evaluation of the frequency and reliability of detection of structural lesions. Methods. Chronic lesions were independently recorded dichotomously (present/absent) from lower C2 to the upper sacrum on T1-weighted MRI scans of 20 patients with ankylosing spondylitis by 4 readers. Prior to the exercise, a series of reference images was developed in which structural lesions were assigned by consensus. We tested a method for scoring new bone formation based on assigning a score of 2 for a bone spur and a score of 6 for intervertebral ankylosis [Canada-Denmark Spur and Ankylosis score (CanDen SAS)]. Results. Focal fat infiltration and non-corner vertebral endplate erosions were observed in the majority of patients and were reliably detected. Vertebral corner erosions were not reliably detected. New bone lesions were also detected in almost all patients, and intervertebral ankylosis was detected with good reliability. Bone spurs were not reliably detected. The CanDen SAS demonstrated excellent interobserver reliability (ICC = 0.93) across 4 readers. Conclusion. Definitions for focal fat infiltration, non-corner vertebral erosions, and intervertebral ankylosis function well as regards reliability. Despite rigorous standardization of definitions, substantial calibration is required for vertebral corner erosions and bone spurs.

Validation of Definitions for Active Inflammatory Lesions Detected by Magnetic Resonance Imaging in the Spine of Patients with Spondyloarthritis

Objective. Assessment of active inflammatory features of spondyloarthritis (SpA) on magnetic resonance imaging (MRI) is of diagnostic and prognostic significance. Further study requires standardization and application of rigorous definitions of the spinal changes observed on MRI. The Canada/Denmark MRI working group has developed a comprehensive list of definitions for active inflammatory spinal lesions. We aimed to conduct a systematic evaluation of the frequency and reliability of detection of active inflammatory lesions as defined by the working group. Methods. Four readers independently recorded dichotomously (present/absent) active inflammatory lesions from lower C2 to the upper sacrum of the spine on STIR MRI scans of 20 patients with ankylosing spondylitis. All lesions were recorded at individual spinal levels except for facet joint lesions, which were recorded according to affected spinal segments. Prior to the exercise, a series of reference images were developed in which active inflammatory lesions were assigned by consensus. Frequency data were analyzed descriptively, while reliability was assessed by Cohen’s unweighted kappa and percentage agreement. Results. Interobserver reliability of vertebral corner inflammatory lesions (CIL) varied substantially between reader pairs and between spinal segments. It was overall less than adequate (kappa < 0.60) for most reader pairs, although the most experienced reader pair achieved good reliability (kappa = 0.68). Reliability was fair to good for lateral segment inflammatory lesions (LIL) and non-corner inflammatory lesions (NIL) (mean kappa for experienced reader pair 0.58 and 0.66, respectively). Conclusion. Detection of CIL, LIL, and NIL was only satisfactory with the most experienced MRI reader pair. Despite rigorous standardization of definitions, detection of active inflammatory lesions is difficult and requires substantial calibration.

Measuring impairments of functioning and health in patients with axial spondyloarthritis by using the ASAS Health Index and the Environmental Item Set: translation and cross-cultural adaptation into 15 languages

Introduction The Assessments of SpondyloArthritis international society Health Index (ASAS HI) measures functioning and health in patients with spondyloarthritis (SpA) across 17 aspects of health and 9 environmental factors (EF). The objective was to translate and adapt the original English version of the ASAS HI, including the EF Item Set, cross-culturally into 15 languages. Methods Translation and cross-cultural adaptation has been carried out following the forward–backward procedure. In the cognitive debriefing, 10 patients/country across a broad spectrum of sociodemographic background, were included. Results The ASAS HI and the EF Item Set were translated into Arabic, Chinese, Croatian, Dutch, French, German, Greek, Hungarian, Italian, Korean, Portuguese, Russian, Spanish, Thai and Turkish. Some difficulties were experienced with translation of the contextual factors indicating that these concepts may be more culturally-dependent. A total of 215 patients with axial SpA across 23 countries (62.3% men, mean (SD) age 42.4 (13.9) years) participated in the field test. Cognitive debriefing showed that items of the ASAS HI and EF Item Set are clear, relevant and comprehensive. All versions were accepted with minor modifications with respect to item wording and response option. The wording of three items had to be adapted to improve clarity. As a result of cognitive debriefing, a new response option ‘not applicable’ was added to two items of the ASAS HI to improve appropriateness. Discussion This study showed that the items of the ASAS HI including the EFs were readily adaptable throughout all countries, indicating that the concepts covered were comprehensive, clear and meaningful in different cultures.

Atlas of Magnetic Resonance Imaging Abnormalities in the Spine in Spondyloarthritis: Definitions, Reliability, Training, and Conceptual Framework. A Report from the Canada (SPARCC) – Denmark International Spondyloarthritis Working Group

Substantial advances in the diagnostic evaluation of spondyloarthritis (SpA) and the assessment of disease activity are due to introduction of magnetic resonance imaging (MRI). Nevertheless, this still constitutes a relatively new imaging modality in the hands of rheumatologists, while most radiologists lack experience in assessment of MRI abnormalities specific to SpA. Perhaps more importantly, there has been little interface between the subspecialties to ensure the use of a common language to avoid misinterpretation and confusion. A standard theme throughout the imaging literature pertaining to rheumatic disease is the lack of standardized definitions to describe abnormalities, and nowhere is this more apparent than in the literature pertaining to MRI. This constitutes a serious impediment to studies of diagnostic utility, assessment of disease activity, and evaluation of prognosis. With regard to the assessment of disease activity, several scoring methods for the evaluation …