title: Integrated multimodal network approach to PET and MRI based on multidimensional persistent homology.
abstract: Finding underlying relationships among multiple imaging modalities in a coherent fashion is one of the challenging problems in multimodal analysis. In this study, we propose a novel approach based on multidimensional persistence. In the extension of the previous threshold-free method of persistent homology, we visualize and discriminate the topological change of integrated brain networks by varying not only threshold but also mixing ratio between two different imaging modalities. The multidimensional persistence is implemented by a new bimodal integration method called 1D projection. When the mixing ratio is predefined, it constructs an integrated edge weight matrix by projecting two different connectivity information onto the one dimensional shared space. We applied the proposed methods to PET and MRI data from 23 attention deficit hyperactivity disorder (ADHD) children, 21 autism spectrum disorder (ASD), and 10 pediatric control subjects. From the results, we found that the brain networks of ASD, ADHD children and controls differ, with ASD and ADHD showing asymmetrical changes of connected structures between metabolic and morphological connectivities. The difference of connected structure between ASD and the controls was mainly observed in the metabolic connectivity. However, ADHD showed the maximum difference when two connectivity information were integrated with the ratio 0.6. These results provide a multidimensional homological understanding of disease-related PET and MRI networks that disclose the network association with ASD and ADHD. Hum Brain Mapp 38:1387-1402, 2017. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, Korea.|Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Korea.
authors.forename: Hyekyoung
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, Korea.|Data Science and Knowledge Creation Research Center, Seoul National University, Seoul, Korea.
authors.forename: Hyejin
authors.initials: H
authors.lastname: Kang
authors.affiliation: Department of Biostatistics and Medical Informatics, University of Wisconsin, Madison, Wisconsin.|Waisman Laboratory for Brain Imaging and Behavior, University of Wisconsin, Madison, Wisconsin.
authors.forename: Moo K
authors.initials: MK
authors.lastname: Chung
authors.affiliation: Department of Mathematical Sciences, Seoul National University College of Natural Sciences, Seoul, Korea.
authors.forename: Seonhee
authors.initials: S
authors.lastname: Lim
authors.affiliation: Division of Child and Adolescent Psychiatry, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Bung-Nyun
authors.initials: BN
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul, Korea.|Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Korea.
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Lee
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000000981:diagnostic imaging* / Q000473:pathology; D000067877:Autism Spectrum Disorder / Q000000981:diagnostic imaging* / Q000473:pathology; D001921:Brain / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D002648:Child; D002675:Child, Preschool; D003198:Computer Simulation; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography
keywords: FDG-PET; T1-weighted MRI; attention deficit hyperactivity disorder; autism spectrum disorder; brain connectivity; multimodal brain image analysis; persistent homology