01 Nov 21. Featured Paper

Rim lesions are demonstrated in early relapsing–remitting multiple sclerosis using 3 T-based susceptibility-weighted imaging in a multi-institutional setting.

Link to paper on Neuroradiology

Authors

Koy Chong Ng Kee Kwong, Daisy Mollison, Rozanna Meijboom, Elizabeth N. York, Agniete Kampaite, Sarah-Jane Martin, David P. J. Hunt, Michael J. Thrippleton, Siddharthan Chandran, Adam D. Waldman & FutureMS consortium

Abstract

Purpose: Rim lesions, characterised by a paramagnetic rim on susceptibility-based MRI, have been suggested to reflect chronic inflammatory demyelination in multiple sclerosis (MS) patients.

Here, we assess, through susceptibility-weighted imaging (SWI), the prevalence, longitudinal volume evolution & clinical associations of rim lesions in subjects with early relapsing–remitting MS (RRMS).

Methods: Subjects (n = 44) with recently diagnosed RRMS underwent 3 T MRI at baseline (M0) & 1 year (M12) as part of a multi-centre study.

SWI was acquired at M12 using a 3D segmented gradient-echo echo-planar imaging sequence.

Rim lesions identified on SWI were manually segmented on FLAIR images at both time points for volumetric analysis.

Results: Twelve subjects (27%) had at least one rim lesion at M12.

A linear mixed-effects model, with ‘subject’ as a random factor, revealed mixed evidence for the difference in longitudinal volume change between rim lesions & non-rim lesions (p = 0.0350 & p = 0.0556 for subjects with & without rim lesions, respectively).

All 25 rim lesions identified showed T1-weighted hypointense signal.

Subjects with & without rim lesions did not differ significantly with respect to age, disease duration or clinical measures of disability (p > 0.05).

Conclusion: We demonstrate that rim lesions are detectable in early-stage RRMS on 3 T MRI across multiple centres, although their relationship to lesion enlargement is equivocal in this small cohort.

Identification of SWI rims was subjective.

Agreed criteria for defining rim lesions & their further validation as a biomarker of chronic inflammation are required for translation of SWI into routine MS clinical practice.

Keywords

• Magnetic resonance imaging
• Multiple sclerosis
• Rim lesions
• Susceptibility-weighted imaging