Introduction of a novel magnetic resonance imaging-based scoring system for assessing disease activity in children with juvenile dermatomyositis

Abstract

ObjectivesWe aimed to develop and assess the reliability of a novel MRI-based scoring system for reporting the severity of MRI findings in children with suspected JDM.MethodsNine consultant paediatric radiologists independently assessed and scored 40 axial and 30 coronal thigh MR images of children with suspected JDM on two occasions using the juvenile dermatomyositis magnetic resonance Imaging Score (JIS). JIS was calculated for both reads for each plane and each limb, with possible scores ranging from 0 (normal) to 100 (severe). Inter- and intraobserver agreement was calculated using the intraclass correlation coefficient (ICC) and two- and one-way random effects models, respectively. Bland-Altman plots of the difference in JIS against the average JIS were also produced for each rater.ResultsOverall, the interobserver reliability and agreement was good—for axial images, JIS ranged from 46.8 to 61.0 [ICC = 0.88 (95% CI: 0.82, 0.92)] for the left limb and 47.9–61.4 [ICC = 0.87 (95% CI: 0.81, 0.92)] for the right limb. For coronal images, JIS ranged from 56.7 to 65.1 [ICC = 0.90 (95% CI: 0.85, 0.95)] for the left limb and 55.7 to 66.8 [ICC = 0.90 (95% CI: 0.84, 0.94)] for the right limb. The intraobserver reliability and agreement was good, with ICC ranging from 0.90 to 0.94.ConclusionJIS is a semi-objective scoring system with potential to serve as a reliable biomarker of disease severity and response to therapeutic interventions in children with JDM.

Juvenile Dermatomyositis Magnetic Resonance Imaging Score (JIS) does not correlate with criteria for clinically inactive disease: a single-centre retrospective evaluation

“…All MRIs were scored by the same radiologist, limiting inter-observer variability. New strategies are required to assess disease activity accurately; JIS could be a valuable tool in making such an assessment, since it provides objective and quantitative measurement of disease activity, making it a reliable biomarker of disease severity and response to therapeutic interventions in children with JDM [14].…”

“…A European consensus guideline supported the use MRI to monitor disease activity [12]. The recently developed and validated Juvenile dermatomyositis Magnetic resonance imaging Score (JIS) was designed for quantifying muscle inflammation, with good inter and intra observer reliability and has the potential to be a useful additional tool in assessing disease activity [13,14]. In our tertiary paediatric rheumatology centre we have regularly used MRI as an adjunct to clinical findings to aid the diagnosis of remission and hence treatment escalation or tapering.…”

Keeping up with the progress in the diagnosis and management of pediatric rheumatic diseases

“…Increased signal intensity reflecting inflammation within muscle correlates better with disease activity than elevation of creatine kinase levels [9]. A novel magnetic resonance imaging-based semi-objective scoring system was recently developed as a reliable biomarker of disease severity and response to therapeutic interventions in children with JDM [10]. MRI could also be very helpful for assessing musculoskeletal and neurological involvements in juvenile localized scleroderma, with the most common encountered deep tissue findings in extremity MRI of fascial thickening and enhancement [11].…”

European Society of Paediatric Radiology 2019 strategic research agenda: improving imaging for tomorrow’s children

“…There are no normal standards for whole-body MRI, which poses particular problems for diagnosing abnormalities [30]. In other areas of musculoskeletal imaging, recent advances have been made regarding image-based classification systems for juvenile dermatomyositis [31] and establishment of normal US-based references for the wrist [32].…”