title: BEaST: brain extraction based on nonlocal segmentation technique.
abstract: Brain extraction is an important step in the analysis of brain images. The variability in brain morphology and the difference in intensity characteristics due to imaging sequences make the development of a general purpose brain extraction algorithm challenging. To address this issue, we propose a new robust method (BEaST) dedicated to produce consistent and accurate brain extraction. This method is based on nonlocal segmentation embedded in a multi-resolution framework. A library of 80 priors is semi-automatically constructed from the NIH-sponsored MRI study of normal brain development, the International Consortium for Brain Mapping, and the Alzheimer's Disease Neuroimaging Initiative databases. In testing, a mean Dice similarity coefficient of 0.9834±0.0053 was obtained when performing leave-one-out cross validation selecting only 20 priors from the library. Validation using the online Segmentation Validation Engine resulted in a top ranking position with a mean Dice coefficient of 0.9781±0.0047. Robustness of BEaST is demonstrated on all baseline ADNI data, resulting in a very low failure rate. The segmentation accuracy of the method is better than two widely used publicly available methods and recent state-of-the-art hybrid approaches. BEaST provides results comparable to a recent label fusion approach, while being 40 times faster and requiring a much smaller library of priors.
authors.affiliation: McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Canada. se@hst.aau.dk
authors.forename: Simon F
authors.initials: SF
authors.lastname: Eskildsen
authors.forename: Pierrick
authors.initials: P
authors.lastname: Coupé
authors.forename: Vladimir
authors.initials: V
authors.lastname: Fonov
authors.forename: José V
authors.initials: JV
authors.lastname: Manjón
authors.forename: Kelvin K
authors.initials: KK
authors.lastname: Leung
authors.forename: Nicolas
authors.initials: N
authors.lastname: Guizard
authors.forename: Shafik N
authors.initials: SN
authors.lastname: Wassef
authors.forename: Lasse Riis
authors.initials: LR
authors.lastname: Østergaard
authors.forename: D Louis
authors.initials: DL
authors.lastname: Collins
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D001921:Brain / Q000033:anatomy & histology*; D001931:Brain Mapping / Q000379:methods; D003201:Computers; D016208:Databases, Factual; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods* / Q000706:statistics & numerical data; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D008297:Male; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D012984:Software; D055815:Young Adult