title: Multi-contrast multi-atlas parcellation of diffusion tensor imaging of the human brain.
abstract: In this paper, we propose a novel method for parcellating the human brain into 193 anatomical structures based on diffusion tensor images (DTIs). This was accomplished in the setting of multi-contrast diffeomorphic likelihood fusion using multiple DTI atlases. DTI images are modeled as high dimensional fields, with each voxel exhibiting a vector valued feature comprising of mean diffusivity (MD), fractional anisotropy (FA), and fiber angle. For each structure, the probability distribution of each element in the feature vector is modeled as a mixture of Gaussians, the parameters of which are estimated from the labeled atlases. The structure-specific feature vector is then used to parcellate the test image. For each atlas, a likelihood is iteratively computed based on the structure-specific vector feature. The likelihoods from multiple atlases are then fused. The updating and fusing of the likelihoods is achieved based on the expectation-maximization (EM) algorithm for maximum a posteriori (MAP) estimation problems. We first demonstrate the performance of the algorithm by examining the parcellation accuracy of 18 structures from 25 subjects with a varying degree of structural abnormality. Dice values ranging 0.8-0.9 were obtained. In addition, strong correlation was found between the volume size of the automated and the manual parcellation. Then, we present scan-rescan reproducibility based on another dataset of 16 DTI images - an average of 3.73%, 1.91%, and 1.79% for volume, mean FA, and mean MD respectively. Finally, the range of anatomical variability in the normal population was quantified for each structure.
authors.affiliation: Center for Imaging Science, Johns Hopkins University, Baltimore, Maryland, United States of America; Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Tang
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Shoko
authors.initials: S
authors.lastname: Yoshida
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: John
authors.initials: J
authors.lastname: Hsu
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Thierry A G M
authors.initials: TA
authors.lastname: Huisman
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Andreia V
authors.initials: AV
authors.lastname: Faria
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Oishi
authors.affiliation: Center for Imaging Science, Johns Hopkins University, Baltimore, Maryland, United States of America.
authors.forename: Kwame
authors.initials: K
authors.lastname: Kutten
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Andrea
authors.initials: A
authors.lastname: Poretti
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Yue
authors.initials: Y
authors.lastname: Li
authors.affiliation: Center for Imaging Science, Johns Hopkins University, Baltimore, Maryland, United States of America; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Michael I
authors.initials: MI
authors.lastname: Miller
authors.affiliation: Center for Imaging Science, Johns Hopkins University, Baltimore, Maryland, United States of America; Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, United States of America.
authors.forename: Susumu
authors.initials: S
authors.lastname: Mori
mesh_terms: D000465:Algorithms; D001921:Brain / Q000002:abnormalities / Q000033:anatomy & histology*; D016022:Case-Control Studies; D002648:Child; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D016013:Likelihood Functions; D008297:Male; D015203:Reproducibility of Results