Evidence for a white matter lesion size threshold to support the diagnosis of relapsing remitting multiple sclerosis

S Grahl; V Pongratz; P Schmidt; C Engl; M Bussas; A Radetz; G Gonzalez-Escamilla; S Groppa; F Zipp; C Lukas; J Kirschke; C Zimmer; M Hoshi; A Berthele; B Hemmer; M Mühlau

doi:10.1016/j.msard.2019.01.042

Evidence for a white matter lesion size threshold to support the diagnosis of relapsing remitting multiple sclerosis

Mult Scler Relat Disord. 2019 Apr:29:124-129. doi: 10.1016/j.msard.2019.01.042. Epub 2019 Jan 28.

Authors

S Grahl¹, V Pongratz¹, P Schmidt¹, C Engl¹, M Bussas¹, A Radetz², G Gonzalez-Escamilla², S Groppa³, F Zipp³, C Lukas⁴, J Kirschke⁵, C Zimmer⁵, M Hoshi⁶, A Berthele⁶, B Hemmer⁷, M Mühlau⁸

Affiliations

¹ Department of Neurology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81541, Munich, Germany; TUM Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81541, Munich, Germany.
² Neurology, University Medical Centre of the Johannes Gutenberg University Mainz and Neuroimaging Center of the Focus Program Translational Neuroscience (FTN-NIC), Langenbeckstr. 1, 55131, Mainz, Germany.
³ Neurology, University Medical Centre of the Johannes Gutenberg University Mainz and Neuroimaging Center of the Focus Program Translational Neuroscience (FTN-NIC), Langenbeckstr. 1, 55131, Mainz, Germany; German Competence Network Multiple Sclerosis (KKNMS).
⁴ German Competence Network Multiple Sclerosis (KKNMS); Diagnostic and Interventional Radiology and Nuclear Medicine, St Josef Hospital, Ruhr, University Bochum, Gudrunstr. 56, 44791, Bochum, Germany.
⁵ Department of Neuroradiology, Technische Universität München, Ismaninger Str. 22, 81541, Munich, Germany.
⁶ Department of Neurology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81541, Munich, Germany.
⁷ Department of Neurology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81541, Munich, Germany; German Competence Network Multiple Sclerosis (KKNMS); Munich Cluster for Systems Neurology (SyNergy), Feodor-Lynen-Str. 17, 81377, Munich, Germany.
⁸ Department of Neurology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81541, Munich, Germany; TUM Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81541, Munich, Germany; German Competence Network Multiple Sclerosis (KKNMS). Electronic address: mark.muehlau@tum.de.

PMID: 30711877
DOI: 10.1016/j.msard.2019.01.042

Abstract

Background: The number of white matter lesions (WML) in brain MRI is the most established paraclinical tool to support the diagnosis of multiple sclerosis (MS) and to monitor its course. Diagnostic criteria have stipulated a minimum detectable diameter of 3 mm per WML, although this threshold is not evidence-based. We aimed to provide a rationale for a WML size threshold for three-dimensional MRI sequences at 3 T by comparing patients with relapsing-remitting MS (RRMS) to control subjects (CS).

Methods: We analyzed MR images from two cohorts, obtained at scanners from two different vendors, each comprising patients with RRMS and CS. Both cohorts were examined with FLAIR and T1w sequences. In total, 232 patients with RRMS (Expanded Disability Status Scale: mean = 1.6 ± 1.2; age: mean = 36 ± 10) as well as 116 age- and sex-matched CS were studied. We calculated odds ratios across WML volumes. The WML size threshold, which discriminated best between patients and CS, was estimated with receiver operating characteristic curve analysis.

Results: In both cohorts, odds ratios increased continuously with increasing WML volumes, and discriminative power was highest at a WML size threshold corresponding to a diameter of about 3 mm.

Conclusion: The stipulated WML size threshold of 3 mm in diameter for the diagnostic criteria of MS seems a reasonable choice for three-dimensional MRI sequences at 3 T.

Keywords: Relapsing-remitting multiple sclerosis; Structural MRI; White matter lesion; White matter lesion size threshold.

MeSH terms

Adult
Female
Humans
Magnetic Resonance Imaging / standards*
Male
Multiple Sclerosis, Relapsing-Remitting / diagnostic imaging*
Multiple Sclerosis, Relapsing-Remitting / pathology
Neuroimaging / standards*
Reference Standards
Retrospective Studies
White Matter / diagnostic imaging*
White Matter / pathology
Young Adult