Development and evaluation of a manual segmentation protocol for deep grey matter in multiple sclerosis: Towards accelerated semi-automated references

Alexandra de Sitter, Jessica Burggraaff*, Fabian Bartel, Miklos Palotai, Yaou Liu, Jorge Simoes, Serena Ruggieri, Katharina Schregel, Stefan Ropele, Maria A. Rocca, Claudio Gasperini, Antonio Gallo, Menno M. Schoonheim, Michael Amann, Marios Yiannakas, Deborah Pareto, Mike P. Wattjes, Jaume Sastre-Garriga, Ludwig Kappos, Massimo FilippiChristian Enzinger, Jette Frederiksen, Bernard Uitdehaag, Charles R. G. Guttmann, Frederik Barkhof, Hugo Vrenken

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Background: Deep grey matter (dGM) structures, particularly the thalamus, are clinically relevant in multiple sclerosis (MS). However, segmentation of dGM in MS is challenging; labeled MS-specific reference sets are needed for objective evaluation and training of new methods. Objectives: This study aimed to (i) create a standardized protocol for manual delineations of dGM; (ii) evaluate the reliability of the protocol with multiple raters; and (iii) evaluate the accuracy of a fast-semi-automated segmentation approach (FASTSURF). Methods: A standardized manual segmentation protocol for caudate nucleus, putamen, and thalamus was created, and applied by three raters on multi-center 3D T1-weighted MRI scans of 23 MS patients and 12 controls. Intra- and inter-rater agreement was assessed through intra-class correlation coefficient (ICC); spatial overlap through Jaccard Index (JI) and generalized conformity index (CIgen). From sparse delineations, FASTSURF reconstructed full segmentations; accuracy was assessed both volumetrically and spatially. Results: All structures showed excellent agreement on expert manual outlines: intra-rater JI > 0.83; inter-rater ICC ≥ 0.76 and CIgen ≥ 0.74. FASTSURF reproduced manual references excellently, with ICC ≥ 0.97 and JI ≥ 0.92. Conclusions: The manual dGM segmentation protocol showed excellent reproducibility within and between raters. Moreover, combined with FASTSURF a reliable reference set of dGM segmentations can be produced with lower workload.
Original languageEnglish
Article number102659
JournalNeuroImage: Clinical
Volume30
DOIs
Publication statusPublished - 1 Jan 2021

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