Spondyloarthritis research consortium of canada magnetic resonance imaging index for assessment of spinal inflammation in ankylosing spondylitis

Abstract

Objective. To develop a feasible magnetic resonance imaging (MRI)-based scoring system for spinal inflammation in patients with spondylarthropathy that requires minimal scan time, does not require contrast enhancement, evaluates the extent of lesions in 3 dimensional planes, and limits the number of vertebral levels that are scored because MRI demonstrates characteristic inflammatory lesions in the spine of patients with ankylosing spondylitis (AS) prior to the development of typical features on plain radiographic. Methods. Our scoring method was based entirely on the assessment of increased signal denoting bone marrow edema on T2-weighted STIR sequences. Blinded MRI films were assessed in random order at 2 sites by 3 blinded readers at each of the 2 sites (the Universities of Alberta and Toronto). Intra-and interreader reliability was assessed by intraclass correlation coefficient. The 24-week response of patients with AS randomized to infliximab:placebo (8:3) was assessed by effect size and standardized response mean.Results. An initial analysis of all discovertebral units (DVUs) in the spine of 11 patients demonstrated a mean of 3.2 (95% confidence interval 3.2, 5.2) affected units, while limiting the scoring to a maximum of 6 units captured most of the affected units. We scanned 11 patients with AS with clinically active disease and 20 additional patients randomized to a 24-week trial of either infliximab or placebo. Intraobserver reproducibility for the 6-DVU STIR score ranged from 0.93 to 0.98 (P < 0.0001). Interobserver reproducibility of scores by readers from both sites was 0.79 (P < 0.0001) for status score and 0.82 (P < 0.0001) for change score. Analysis of pretreatment and posttreatment scores for all 20 patients randomized to infliximab/placebo showed a large degree of responsiveness (standardized response mean ‫؍‬ 0.87). Reproducibility and responsiveness were only slightly improved by using contrast enhancement with gadolinium diethylenetriaminepentaacetic acid. Conclusion. The Spondyloarthritis Research Consortium of Canada MRI index is a feasible, reproducible, and responsive index for measuring spinal inflammation in AS.

Focal fat lesions at vertebral corners on magnetic resonance imaging predict the development of new syndesmophytes in ankylosing spondylitis

“…In reading the MR images, we adhered to standardized definitions for acute and chronic spinal lesions observed on MRI in patients with AS that were developed by the Spondyloarthritis 2216 CHIOWCHANWISAWAKIT ET AL Research Consortium of Canada (SPARCC) as well as an international working group of rheumatologists and radiologists from Canada and Denmark (16,18,22). For the purposes of this study, we have focused on the identification of focal fat infiltration and inflammation at the anterior corners of the vertebral bodies.…”

Evaluation of the diagnostic utility of spinal magnetic resonance imaging in axial spondylarthritis

“…The Leeds Scoring System (6,12) was used to score spinal BME as well as BME of the SI joints on STIR sequences. BME was defined, according to the OMERACT definitions (22,23), as low signal intensity on the T1 sequence and high/ intermediate bone marrow signals with irregular contour on the STIR image, when compared with normal bone marrow signals coming from the sacral interforaminal area in the SI joint scans or the center of an unaffected vertebra in the spinal scans, similar to the Spondyloarthritis Research Consortium of Canada definition (9).…”

“…In addition to the scoring of active BME lesions, structural changes, as shown by the presence or absence of erosions and ankylosis, were also recorded, with erosions identified as subchondral defects with a low signal on T1-weighted images, and ankylosis defined as complete bridging of the SI joints with total loss of joint space on T1 sequences. 1332 BENNETT ET AL For the spine, the Leeds Scoring System was used to identify different patterns of vertebral lesions, since some patterns of acute vertebral inflammation are thought to also occur frequently in DA (9,19). The scoring system was modified to grade the severity of the lesions, since it was considered important to use a semiquantitative system rather than a dichotomous system to grade the severity of spinal lesions, because severity of BME lesions in the SI joints has been shown to play a role in the early diagnosis of AS (3).…”

“…The scoring system was modified to grade the severity of the lesions, since it was considered important to use a semiquantitative system rather than a dichotomous system to grade the severity of spinal lesions, because severity of BME lesions in the SI joints has been shown to play a role in the early diagnosis of AS (3). We decided to modify the Leeds Scoring System rather than use other available scoring systems (9)(10)(11), since other systems do not include posterior elements (25), which is an area that seems to be highly relevant to SpA, as has also been noted by other authors (26,27).…”

“…It is generally assumed that these MRI patterns of disease can be used to distinguish SpA from other diseases. Indeed, these lesions are being used to diagnose axial SpA early in its onset (3,8) and might influence early initiation of biologic therapy; for this purpose, several systems of scoring spinal BME lesions have been established (6,(9)(10)(11)(12). However, the specificity of these spinal BME lesions for SpA and their diagnostic utility for SpA have not been confirmed.…”