A simple, clinically usable whole-body MRI system of joint assessment in adolescents and young people with juvenile idiopathic arthritis

Varvara Choida; Timothy J P Bray; Niels van Vucht; Maaz Ali Abbasi; Alan P Bainbridge; Thomas Parry; Debajit Sen; Sue Mallett; Coziana Ciurtin; Margaret A Hall-Craggs

doi:10.1093/rheumatology/keae117

A simple, clinically usable whole-body MRI system of joint assessment in adolescents and young people with juvenile idiopathic arthritis

Rheumatology (Oxford). 2024 Feb 29:keae117. doi: 10.1093/rheumatology/keae117. Online ahead of print.

Authors

Varvara Choida^{1

2

3}, Timothy J P Bray^{1

4}, Niels van Vucht⁴, Maaz Ali Abbasi⁴, Alan P Bainbridge^{1

5}, Thomas Parry¹, Debajit Sen^{2

3}, Sue Mallett¹, Coziana Ciurtin^{2

3}, Margaret A Hall-Craggs^{1

4}

Affiliations

¹ Centre for Medical Imaging, University College London, University College London, London, UK.
² Centre for Adolescent Rheumatology, Division of Medicine, University College London, UK.
³ Department of Rheumatology, University College London Hospitals NHS Foundation Trust, London, UK.
⁴ Department of Imaging, University College London Hospitals NHS Foundation Trust, London, UK.
⁵ Department of Medical Physics, University College Hospitals Trust, London, UK.

PMID: 38426363
DOI: 10.1093/rheumatology/keae117

Abstract

Objectives: To introduce and evaluate a simple method for assessing joint inflammation and structural damage on whole-body MRI (WBMRI) in juvenile idiopathic arthritis (JIA), which is usable in clinical practice.

Methods: The proposed system utilises post-contrast Dixon WBMRI scans. Joints are assessed for synovitis (grade 0-2) and structural damage (present/absent) at 81 sites. The synovitis grading is based on features including above-normal intensity synovial enhancement, synovial hypertrophy, joint effusion, subarticular bone marrow oedema and peri-articular soft tissue oedema.This system was evaluated in a prospective study of 60 young people (47 patients with JIA and 13 controls with non-inflammatory musculoskeletal pain) who underwent a WBMRI. Three readers (blinded to diagnosis) independently reviewed all images and re-reviewed 20 individual scans. The intra- and inter-reader overall agreement (OA) and the intra- and inter-reader Gwet's agreement coefficients 2 (GAC2) were measured for the detection of a) participants with ≥1 joint with inflammation or structural damage and b) joint inflammation or structural damage for each joint.

Results: The inter-reader OA for detecting patients with ≥1 joint with inflammation, defined as grade 2 synovitis (G2), and ≥1 joint with structural damage were 80% and 73%, respectively. The intra-reader OA for readers 1-3 were 80-90% and 75-90% respectively. The inter-reader OA and GAC2 for joint inflammation (G2) at each joint were both ≥85% for all joints but were lower if grade 1 synovitis was included as positive.

Conclusion: The intra- and inter-reader agreements of this WBMRI assessment system are adequate for assessing objective joint inflammation and damage in JIA.

Keywords: Dixon; JIA; MRI; activity; agreement; joint; reliability; scoring; synovitis; whole-body.