Magnetic resonance imaging of sacroiliitis in children: frequency of findings and interobserver reliability

Katharine E Orr,Athimalaipet V Ramanan,Flavia Menegotto,Savvas Andronikou,Izidora Holjar-Erlic,Marc James Bramham

doi:10.1007/s00247-018-4185-x

Katharine E Orr, Athimalaipet V Ramanan + Show 4 more

Open Access

https://doi.org/10.1007/s00247-018-4185-x

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Abstract

BackgroundClinicians increasingly rely on imaging in juvenile idiopathic arthritis (JIA) to identify sacroiliitis and guide treatment. However, there is limited evidence about magnetic resonance imaging (MRI) for sacroiliitis in children, and interobserver reliability is variable.ObjectiveIdentify the frequency of MRI findings in children with suspected sacroiliitis, calculate inter-reporter reliability and assess the value of diffusion-weighted imaging and contrast-enhanced sequences.Materials and methodsWe retrospectively reviewed 3 years of sacroiliac joint MRI records for suspected sacroiliitis in patients <21 years at a United Kingdom tertiary referral paediatric hospital. Five radiologists (panel of three radiologists and two independent radiologists) reviewed all MRI examinations using a pictorial checklist to identify oedema, effusions, diffusion-weighted signal abnormality, enhancement, erosions and sclerosis. The frequency of panel findings was reported. Interobserver agreement was calculated using the Cohen kappa coefficient.ResultsAn MRI diagnosis of sacroiliitis was made in 12 of 99 examinations (12%). The findings in all scans included oedema (9%), erosions (8%), diffusion-weighted signal abnormality (6%), abnormal enhancement (6%) and effusion (4%). All scans with abnormal contrast enhancement had other MRI features of sacroiliitis. Interobserver agreement was slight to moderate.ConclusionOedema and erosions were the most common findings. Inter-reporter reliability was variable with at best moderate agreement for the presence of sacroiliitis and erosions. The use of contrast enhancement for diagnosing sacroiliitis in children with JIA may be questionable.

Highlights

Sacroiliitis affects 30% of children with the enthesitis-related arthritis subtype of juvenile idiopathic arthritis (JIA) [1]
Sacroiliitis causes reduced mobility and disability [5], with worse functional status in those presenting as children [3]
Referral criteria for magnetic resonance imaging (MRI) investigation for suspected sacroiliitis at this institution were teenagers presenting with back pain or children of any age with known JIA and back pain

Summary

Introduction

Sacroiliitis affects 30% of children with the enthesitis-related arthritis subtype of juvenile idiopathic arthritis (JIA) [1]. Patients with juvenile spondyloarthritis present with lower limb arthritis and enthesitis, with sacroiliitis occurring later [2, 3]. Anti-tumour necrosis factor drugs as first-line agents for sacroiliitis increase mobility, improve quality of life and reduce pain [3, 6,7,8,9,10]. Clinicians rely on imaging in JIA to identify those with axial disease who would benefit from biologics, highlighting the importance of quality imaging and reliable reporting to allow correct patient selection. Clinicians increasingly rely on imaging in juvenile idiopathic arthritis (JIA) to identify sacroiliitis and guide treatment. There is limited evidence about magnetic resonance imaging (MRI) for sacroiliitis in children, and interobserver reliability is variable

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Conclusion