title: On characterizing population commonalities and subject variations in brain networks.
abstract: Brain networks based on resting state connectivity as well as inter-regional anatomical pathways obtained using diffusion imaging have provided insight into pathology and development. Such work has underscored the need for methods that can extract sub-networks that can accurately capture the connectivity patterns of the underlying population while simultaneously describing the variation of sub-networks at the subject level. We have designed a multi-layer graph clustering method that extracts clusters of nodes, called 'network hubs', which display higher levels of connectivity within the cluster than to the rest of the brain. The method determines an atlas of network hubs that describes the population, as well as weights that characterize subject-wise variation in terms of within- and between-hub connectivity. This lowers the dimensionality of brain networks, thereby providing a representation amenable to statistical analyses. The applicability of the proposed technique is demonstrated by extracting an atlas of network hubs for a population of typically developing controls (TDCs) as well as children with autism spectrum disorder (ASD), and using the structural and functional networks of a population to determine the subject-level variation of these hubs and their inter-connectivity. These hubs are then used to compare ASD and TDCs. Our method is generalizable to any population whose connectivity (structural or functional) can be captured via non-negative network graphs.
authors.affiliation: Center for Biomedical Image Computing and Analytics, Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States . Electronic address: yasser.ghanbari@uphs.upenn.edu.
authors.forename: Yasser
authors.initials: Y
authors.lastname: Ghanbari
authors.affiliation: Center for Biomedical Image Computing and Analytics, Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States ; Center for Autism Research, Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States.
authors.forename: Luke
authors.initials: L
authors.lastname: Bloy
authors.affiliation: Center for Biomedical Image Computing and Analytics, Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States.
authors.forename: Birkan
authors.initials: B
authors.lastname: Tunc
authors.affiliation: Center for Biomedical Image Computing and Analytics, Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States.
authors.forename: Varsha
authors.initials: V
authors.lastname: Shankar
authors.affiliation: Center for Autism Research, Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States.
authors.forename: Timothy P L
authors.initials: TPL
authors.lastname: Roberts
authors.affiliation: Center for Autism Research, Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States.
authors.forename: J Christopher
authors.initials: JC
authors.lastname: Edgar
authors.affiliation: Center for Autism Research, Children's Hospital of Philadelphia, Philadelphia, PA 19104, United States.
authors.forename: Robert T
authors.initials: RT
authors.lastname: Schultz
authors.affiliation: Center for Biomedical Image Computing and Analytics, Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States.
authors.forename: Ragini
authors.initials: R
authors.lastname: Verma
mesh_terms: D000293:Adolescent; D000465:Algorithms; D000067877:Autism Spectrum Disorder / Q000000981:diagnostic imaging; D001921:Brain / Q000000981:diagnostic imaging* / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D002648:Child; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000000981:diagnostic imaging*
keywords: Autism spectrum disorder; Connectivity analysis; Multi-layer graph clustering; Non-negative matrix factorization; Population difference