title: Spatio-angular consistent construction of neonatal diffusion MRI atlases.
abstract: Atlases constructed using diffusion-weighted imaging are important tools for studying human brain development. Atlas construction is in general a two-step process involving spatial registration and fusion of individual images. The focus of most studies so far has been on improving the accuracy of registration while image fusion is commonly performed using simple averaging, often resulting in fuzzy atlases. In this article, we propose a patch-based method for diffusion-weighted (DW) atlas construction. Unlike other atlases that are based on the diffusion tensor model, our atlas is model-free and generated directly from the diffusion-weighted images. Instead of independently generating an atlas for each gradient direction and hence neglecting angular image correlation, we propose to construct the atlas by jointly considering DW images of neighboring gradient directions. We employ a group regularization framework where local patches of angularly neighboring images are constrained for consistent spatio-angular atlas reconstruction. Experimental results confirm that our atlas, constructed for neonatal data, reveals more structural details with higher fractional anisotropy than the atlas generated without angular consistency as well as the average atlas. Also the normalization of test subjects to the proposed atlas results in better alignment of brain structures. Hum Brain Mapp 38:3175-3189, 2017. © 2017 Wiley Periodicals, Inc.
authors.affiliation: Department of Radiology and the Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, North Carolina.
authors.forename: Behrouz
authors.identifier: 0000-0003-1605-1825
authors.initials: B
authors.lastname: Saghafi
authors.affiliation: Department of Radiology and the Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, North Carolina.
authors.forename: Jaeil
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Radiology and the Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, North Carolina.
authors.forename: Geng
authors.initials: G
authors.lastname: Chen
authors.affiliation: Department of Radiology and the Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, North Carolina.|Cedars-Sinai, Biomedical Imaging Research Institute, 8700 Beverly Blvd, Los Angeles, California.
authors.forename: Feng
authors.initials: F
authors.lastname: Shi
authors.affiliation: Department of Radiology and the Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, North Carolina.
authors.forename: Weili
authors.initials: W
authors.lastname: Lin
authors.affiliation: Department of Radiology and the Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, North Carolina.
authors.forename: Pew-Thian
authors.initials: PT
authors.lastname: Yap
authors.affiliation: Department of Radiology and the Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, North Carolina.|Department of Brain and Cognitive Engineering, Korea University, Seoul, 02841, Republic of Korea.
authors.forename: Dinggang
authors.initials: D
authors.lastname: Shen
mesh_terms: D000465:Algorithms; D001921:Brain / Q000000981:diagnostic imaging* / Q000254:growth & development*; D001931:Brain Mapping; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009434:Neural Pathways / Q000000981:diagnostic imaging* / Q000254:growth & development*; D066127:White Matter / Q000000981:diagnostic imaging
keywords: diffusion MRI; multi-task learning; neonatal brain atlases; sparse representation; spatio-angular consistency