@inproceedings{9e477661d47f475780cc4bbaf05b3142,
title = "Joint longitudinal modeling of brain appearance in multimodal MRI for the characterization of early brain developmental processes",
abstract = "Early brain maturational processes such as myelination manifest as changes in the relative appearance of white-gray matter tissue classes in MR images. Imaging modalities such as T1W (T1-Weighted) and T2W (T2-Weighted) MRI each display specific patterns of appearance change associated with distinct neurobiological components of these maturational processes. In this paper we present a framework to jointly model multimodal appearance changes across time for a longitudinal imaging dataset, resulting in quantitative assessment of the patterns of early brain maturation not yet available to clinicians. We measure appearance by quantifying contrast between white and gray matter in terms of the distance between their intensity distributions, a method demonstrated to be relatively stable to interscan variability. A multivariate nonlinear mixed effects (NLME) model is used for joint statistical modeling of this contrast measure across multiple imaging modalities. The multivariate NLME procedure considers correlations between modalities in addition to intra-modal variability. The parameters of the logistic growth function used in NLME modeling provide useful quantitative information about the timing and progression of contrast change in multimodal datasets. Inverted patterns of relative white-gray matter intensity gradient that are observable in T1W scans with respect to T2W scans are characterized by the SIR (Signal Intensity Ratio). The CONTDIR (Contrast Direction) which measures the direction of the gradient at each time point relative to that in the adult-like scan adds a directional attribute to contrast. The major contribution of this paper is a framework for joint multimodal temporal modeling of white-gray matter MRI contrast change and estimation of subject-specific and population growth trajectories. Results confirm qualitative descriptions of growth patterns in pediatric radiology studies and our new quantitative modeling scheme has the potential to advance understanding of variability of brain tissue maturation and to eventually differentiate normal from abnormal growth for early diagnosis of pathology.",
author = "Avantika Vardhan and Marcel Prastawa and Neda Sadeghi and Clement Vachet and Joseph Piven and Guido Gerig",
note = "Publisher Copyright: {\textcopyright} Springer International Publishing Switzerland 2015; 3rd International Workshop on Spatio-temporal Image Analysis for Longitudinal and Time-Series Image Data, STIA 2014 in conjunction with the International Conference on Medical Image Computing and Computer Assisted Intervention, MICCAI 2014 ; Conference date: 18-09-2014 Through 18-09-2014",
year = "2015",
doi = "10.1007/978-3-319-14905-9_5",
language = "English (US)",
series = "Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)",
publisher = "Springer Verlag",
pages = "49--63",
editor = "Stanley Durrleman and Tom Fletcher and Guido Gerig and Marc Niethammer and Xavier Pennec",
booktitle = "Spatio-temporal Image Analysis for Longitudinal and Time-Series Image Data - 3rd International Workshop, STIA 2014 Held in Conjunction with MICCAI 2014, Revised Selected Papers",
}