کد مقاله کد نشریه سال انتشار مقاله انگلیسی ترجمه فارسی نسخه تمام متن
4953324 1443004 2018 17 صفحه PDF سفارش دهید دانلود کنید
عنوان انگلیسی مقاله
Director Field Analysis (DFA): Exploring Local White Matter Geometric Structure in Diffusion MRI
موضوعات مرتبط
مهندسی و علوم پایه مهندسی کامپیوتر گرافیک کامپیوتری و طراحی به کمک کامپیوتر
پیش نمایش صفحه اول مقاله
Director Field Analysis (DFA): Exploring Local White Matter Geometric Structure in Diffusion MRI
چکیده انگلیسی


- We introduce concepts of director, orientational order, orientational distortion from liquid crystals to diffusion MRI.
- It is the first work to quantitatively describe orientational distortion (splay, twist, and bend) in diffusion MRI.
- We provide a set of mathematical tools to process general director data which consists of dyadic tensors that have orientations but no direction.
- Orientational Order (OO) and Orientational Dispersion (OD) indices are proposed to describe the degree of alignment and dispersion of a spherical function.
- We propose three indices to describe three types of orientational distortion (splay, twist, and bend) in a local spatial neighborhood, and a total distortion index to describe distortions of all three types.

In Diffusion Tensor Imaging (DTI) or High Angular Resolution Diffusion Imaging (HARDI), a tensor field or a spherical function field (e.g., an orientation distribution function field), can be estimated from measured diffusion weighted images. In this paper, inspired by the microscopic theoretical treatment of phases in liquid crystals, we introduce a novel mathematical framework, called Director Field Analysis (DFA), to study local geometric structural information of white matter based on the reconstructed tensor field or spherical function field: (1) We propose a set of mathematical tools to process general director data, which consists of dyadic tensors that have orientations but no direction. (2) We propose Orientational Order (OO) and Orientational Dispersion (OD) indices to describe the degree of alignment and dispersion of a spherical function in a single voxel or in a region, respectively; (3) We also show how to construct a local orthogonal coordinate frame in each voxel exhibiting anisotropic diffusion; (4) Finally, we define three indices to describe three types of orientational distortion (splay, bend, and twist) in a local spatial neighborhood, and a total distortion index to describe distortions of all three types. To our knowledge, this is the first work to quantitatively describe orientational distortion (splay, bend, and twist) in general spherical function fields from DTI or HARDI data. The proposed DFA and its related mathematical tools can be used to process not only diffusion MRI data but also general director field data, and the proposed scalar indices are useful for detecting local geometric changes of white matter for voxel-based or tract-based analysis in both DTI and HARDI acquisitions. The related codes and a tutorial for DFA will be released in DMRITool.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Medical Image Analysis - Volume 43, January 2018, Pages 112-128
نویسندگان
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