The anisotropic elastic constants of human cortical bone were predicted using a specimen-specific micromechanical model that accounted for structural parameters across multiple length scales. At the nano-scale, the elastic constants of the mineralized collagen fibril were estimated from measured volume fractions of the constituent phases, namely apatite crystals and Type I collagen. The elastic...

We propose a linear-elastic registration method to register diffusion-weighted MRI (DW-MRI) data sets by mapping their diffusion orientation distribution functions (ODFs). The ODFs were reconstructed using a q-ball imaging (QBI) technique to resolve intravoxel fiber crossing. The registration method is based on mapping the ODF maps represented by spherical harmonics which yield analytic solutio...

Introduction and Background. High angular resolution distribution diffusion imaging (HARDI) implicitly captures information about the structure in which the diffusion process takes place. HARDI allows examination of relatively wide range of diffusion signal angular frequencies that, due to the complexity of both diffusion process and its milieu, may spread over multiple bands. In consequence, w...

PURPOSE To develop a bootstrap method to assess the quality of High Angular Resolution Diffusion Imaging (HARDI) data using Q-Ball imaging (QBI) reconstruction. MATERIALS AND METHODS HARDI data were re-shuffled using regular bootstrap with jackknife sampling. For each bootstrap dataset, the diffusion orientation distribution function (ODF) was estimated voxel-wise using QBI reconstruction bas...

Abstract Materials design aims to identify the material features that provide optimal properties for various engineering applications, such as aerospace, automotive, and naval. One of important but challenging problems materials is discover multiple polycrystalline microstructures with properties. This paper proposes an end-to-end artificial intelligence (AI)-driven microstructure optimization ...

We present a new methodology based on directional data clustering to represent white matter fiber orientations in magnetic resonance analyses for high angular resolution diffusion imaging. A probabilistic methodology is proposed for estimating intravoxel principal fiber directions, based on clustering directional data arising from orientation distribution function (ODF) profiles. ODF reconstruc...

In this work, large-scale atomistic modeling is conducted to explore a relatively cold consolidation process: nanoparticles compressed by a stress wave from a sacrificial layer that is ablated by a picosecond laser. The temperature, stress, atomic configuration, and crystallinity are studied in detail to understand the structural behaviors under extreme compression. Study of the temperature and...

C. Lin, W. I. Tseng, L. Kuo, V. J. Wedeen, J. Chen Interdisciplinary MRI/MRS Lab at Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, Center for Optoelectronic Biomedicine, National Taiwan University College of Medicine, Taipei, Taiwan, MGH Martinos Center for Biomedical Imaging, Harvard Medical School, Charlestown, MA, United States Synopsis DSI reflects the dis...

Diffusion MRI has become an established research tool for the investigation of tissue structure and orientation. Since its inception, Diffusion MRI has expanded considerably to include a number of variations such as diffusion tensor imaging (DTI), diffusion spectrum imaging (DSI) and Q-ball imaging (QBI). The acquisition and analysis of such data is very challenging due to its complexity. Recen...

INTRODUCTION: The quest of diffusion-weighted (DW) imaging is to non-invasively obtain information about the average diffusion of water molecules in biological tissue. Many recent high angular resolution diffusion imaging (HARDI) [1, and references therein] techniques are proposed to infer the diffusion or fiber orientation distribution function (ODF), but this ODF only captures the angular str...