Download or read book Investigation and Development of High Angular Resolution Diffusion Imaging written by 卓冠宏 and published by . This book was released on 2009 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of High Angular Resolution Diffusion Imaging Analysis Paradigms for the Investigation of Neuropathology written by Luke Bloy and published by . This book was released on 2012 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Introduction to Diffusion Tensor Imaging written by Susumu Mori and published by Academic Press. This book was released on 2013-08-02 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: The concepts behind diffusion tensor imaging (DTI) are commonly difficult to grasp, even for magnetic resonance physicists. To make matters worse, a many more complex higher-order methods have been proposed over the last few years to overcome the now well-known deficiencies of DTI. In Introduction to Diffusion Tensor Imaging: And Higher Order Models, these concepts are explained through extensive use of illustrations rather than equations to help readers gain a more intuitive understanding of the inner workings of these techniques. Emphasis is placed on the interpretation of DTI images and tractography results, the design of experiments, and the types of application studies that can be undertaken. Diffusion MRI is a very active field of research, and theories and techniques are constantly evolving. To make sense of this constantly shifting landscape, there is a need for a textbook that explains the concepts behind how these techniques work in a way that is easy and intuitive to understand—Introduction to Diffusion Tensor Imaging fills this gap. Extensive use of illustrations to explain the concepts of diffusion tensor imaging and related methods Easy to understand, even without a background in physics Includes sections on image interpretation, experimental design, and applications Up-to-date information on more recent higher-order models, which are increasingly being used for clinical applications
Download or read book Atlas of Human Brain Connections written by Marco Catani and published by Oxford University Press, USA. This book was released on 2012-06-14 with total page 533 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the major challenges of modern neuroscience is to define the complex pattern of neural connections that underlie cognition and behaviour. This atlas capitalises on novel diffusion MRI tractography methods to provide a comprehensive overview of connections derived from virtual in vivo tractography dissections of the human brain.
Download or read book High Angular Resolution Diffusion MRI written by Maxime Descoteaux and published by . This book was released on 2008 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: At the current resolution of diffusion-weighted (DW) magnetic resonance imaging (MRI), research groups agree that there are between one third to two thirds of imaging voxels in the human brain white matter that contain fiber crossing bundles. This thesis tackles the important problem of recovering fiber crossing bundles from DW-MRI measurements. The main goal is to overcome the limitations of diffusion tensor imaging (DTI). It is well-known that imaging voxels where there are multiple fiber crossings produce a non-Gaussian DW signal. This is precisely where DTI is limited due to the intrinsic Gaussian assumption of the technique. Hence, this thesis is dedicated to the development of local reconstruction methods, segmentation and tractography algorithms able to infer multiple fiber crossing from DW-MRI data. To do so, high angular resolution diffusion imaging (HARDI) is used to measure DW images along several directions. Q-ball imaging (QBI) is a recent such HARDI technique that reconstructs the diffusion orientation distribution function (ODF), a spherical function that has its maxima aligned with the underlying fiber directions at every voxel. QBI and the diffusion ODF will play a central role in this thesis.There are many original contributions in this thesis. First, we propose a robust estimation of the HARDI signal using a closed-form regularization algorithm based on the spherical harmonics. Then, we estimate the apparent coefficient coefficient (ADC) to study HARDI anisotropy measures and to discriminate voxels with underlying isotropic, single fiber and multiple fiber distributions. Next, we develop a linear, robust and analytical QBI solution using the spherical harmonic basis, which is used in a new statistical region-based active contour algorithm to segment important white matter fiber bundles. In addition, we develop a new spherical deconvolution sharpening method that transforms the diffusion q-ball ODF into a fiber ODF. Finally, we propose a new deterministic tractography algorithm and a new probabilistic tractography algorithm exploiting the full distribution of the fiber ODF. Overall, we show local reconstruction, segmentation and tracking results on complex fiber regions with known fiber crossing on simulated HARDI data, on a biological phantom and on multiple human brain datasets. Most current DTI based methods neglect these complex fibers, which might lead to wrong interpretations of the brain anatomy and functioning.
Download or read book Optimized Analysis and Population Statistics for High Angular Resolution Diffusion Imaging written by Lian Zhan and published by . This book was released on 2011 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multi Compartment Model Estimation and Analysis in High Angular Resolution Diffusion Imaging written by Xinghua Zhu and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Multi-compartment Model Estimation and Analysis in High Angular Resolution Diffusion Imaging" by Xinghua, Zhu, 朱星华, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Diffusion weighted magnetic resonance images offer unique insights into the neural networks of in vivo human brain. In this study, we investigate estimation and statistical analysis of multi-compartment models in high angular resolution diffusion imaging (HARDI) involving the Rician noise model. In particular, we address four important issues in multi-compartment diffusion model estimation, namely, the modelling of Rician noise in diffusion weighted (DW) images, the automatic determination of the number of compartments in the diffusion signal, the application of spatial prior on multi-compartment models, and the evaluation of parameter indeterminacy in diffusion models. We propose an expectation maximization (EM) algorithm to estimate the parameters of a multi-compartment model by maximizing the Rician likelihood of the diffusion signal. We introduce a novel scheme for automatically selecting the number of compartments, via a sparsity-inducing prior on the compartment weights. A non-local weighted maximum likelihood estimator is proposed to improve estimation accuracy utilizing repetitive patterns in the image. Experimental results show that the proposed algorithm improves estimation accuracy in low signal-to-noise-ratio scenarios, and it provides better model selection than several alternative strategies. In addition, we derive the Cramer-Rao Lower Bound (CRLB) of the maximum Rician likelihood estimator for the balland-stick model and general differentiable diffusion models. The CRLB provides a general theoretical tool for comparing diffusion models and examining parameter indeterminacy in the maximum likelihood estimation problem. DOI: 10.5353/th_b5223987 Subjects: Diffusion magnetic resonance imaging
Download or read book Neuroimaging in Developmental Clinical Neuroscience written by Judith M. Rumsey and published by Cambridge University Press. This book was released on 2009-02-19 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern neuroimaging offers tremendous opportunities for gaining insights into normative development and a wide array of developmental neuropsychiatric disorders. Focusing on ontogeny, this text covers basic processes involved in both healthy and atypical maturation, and also addresses the range of neuroimaging techniques most widely used for studying children. This book will enable you to understand normative structural and functional brain maturation and the mechanisms underlying basic developmental processes; become familiar with current knowledge and hypotheses concerning the neural bases of developmental neuropsychiatric disorders; and learn about neuroimaging techniques, including their unique strengths and limitations. Coverage includes normal developmental processes, atypical processing in developmental neuropsychiatric disorders, ethical issues, neuroimaging techniques and their integration with psychopharmacologic and molecular genetic research approaches, and future directions. This comprehensive volume is an essential resource for neurologists, neuropsychologists, psychiatrists, pediatricians, and radiologists concerned with normal development and developmental neuropsychiatric disorders.
Download or read book Diffusion MRI written by Derek K Jones and published by Oxford University Press. This book was released on 2010-11-11 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt: Professor Derek Jones, a world authority on diffusion MRI, has assembled most of the world's leading scientists and clinicians developing and applying diffusion MRI to produce an authorship list that reads like a "Who's Who" of the field and an essential resource for those working with diffusion MRI. Destined to be a modern classic, this definitive and richly illustrated work covers all aspects of diffusion MRI from basic theory to clinical application. Oxford Clinical Neuroscience is a comprehensive, cross-searchable collection of resources offering quick and easy access to eleven of Oxford University Press's prestigious neuroscience texts. Joining Oxford Medicine Online these resources offer students, specialists and clinical researchers the best quality content in an easy-to-access format.
Download or read book Visualization and Processing of Tensor Fields written by Joachim Weickert and published by Springer Science & Business Media. This book was released on 2007-06-25 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: Matrix-valued data sets – so-called second order tensor fields – have gained significant importance in scientific visualization and image processing due to recent developments such as diffusion tensor imaging. This book is the first edited volume that presents the state of the art in the visualization and processing of tensor fields. It contains some longer chapters dedicated to surveys and tutorials of specific topics, as well as a great deal of original work by leading experts that has not been published before. It serves as an overview for the inquiring scientist, as a basic foundation for developers and practitioners, and as as a textbook for specialized classes and seminars for graduate and doctoral students.
Download or read book Investigating the human brainstem with structural and functional MRI written by Florian Beissner and published by Frontiers E-books. This book was released on 2014-07-30 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: The brainstem is one of the least understood parts of the human brain despite its prime importance for the maintenance of basic vital functions. Owing to its role as a relay station between spinal cord, cerebellum and neocortex, the brainstem contains vital nodes of all functional systems in the central nervous system, including the visual, auditory, gustatory, vestibular, somatic and visceral senses, and the somatomotor as well as autonomic nervous systems. While the brainstem has been extensively studied in animals using invasive methods, human studies remain scarce. Magnetic resonance imaging (MRI) as a non-invasive and widely available method is one possibility to access the brainstem in humans and measure its structure as well as function. The close vicinity of the brainstem to large arteries and ventricles and the small size of the anatomical structures, however, place high demands on imaging as well as data analysis methods. Nevertheless, the field of brainstem-(f)MRI has significantly advanced in the past few years, largely due to the development of several new tools that facilitate studying this critical part of the human brain. Within this scope, the goal of this Research Topic is to compile work representing the state of the art in functional and structural MRI of the human brainstem.
Download or read book Quantitative Magnetic Resonance Imaging written by Nicole Seiberlich and published by Academic Press. This book was released on 2020-11-18 with total page 1094 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantitative Magnetic Resonance Imaging is a ‘go-to’ reference for methods and applications of quantitative magnetic resonance imaging, with specific sections on Relaxometry, Perfusion, and Diffusion. Each section will start with an explanation of the basic techniques for mapping the tissue property in question, including a description of the challenges that arise when using these basic approaches. For properties which can be measured in multiple ways, each of these basic methods will be described in separate chapters. Following the basics, a chapter in each section presents more advanced and recently proposed techniques for quantitative tissue property mapping, with a concluding chapter on clinical applications. The reader will learn: The basic physics behind tissue property mapping How to implement basic pulse sequences for the quantitative measurement of tissue properties The strengths and limitations to the basic and more rapid methods for mapping the magnetic relaxation properties T1, T2, and T2* The pros and cons for different approaches to mapping perfusion The methods of Diffusion-weighted imaging and how this approach can be used to generate diffusion tensor maps and more complex representations of diffusion How flow, magneto-electric tissue property, fat fraction, exchange, elastography, and temperature mapping are performed How fast imaging approaches including parallel imaging, compressed sensing, and Magnetic Resonance Fingerprinting can be used to accelerate or improve tissue property mapping schemes How tissue property mapping is used clinically in different organs Structured to cater for MRI researchers and graduate students with a wide variety of backgrounds Explains basic methods for quantitatively measuring tissue properties with MRI - including T1, T2, perfusion, diffusion, fat and iron fraction, elastography, flow, susceptibility - enabling the implementation of pulse sequences to perform measurements Shows the limitations of the techniques and explains the challenges to the clinical adoption of these traditional methods, presenting the latest research in rapid quantitative imaging which has the possibility to tackle these challenges Each section contains a chapter explaining the basics of novel ideas for quantitative mapping, such as compressed sensing and Magnetic Resonance Fingerprinting-based approaches
Download or read book Anisotropy Across Fields and Scales written by Evren Özarslan and published by Springer Nature. This book was released on 2021 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book focuses on processing, modeling, and visualization of anisotropy information, which are often addressed by employing sophisticated mathematical constructs such as tensors and other higher-order descriptors. It also discusses adaptations of such constructs to problems encountered in seemingly dissimilar areas of medical imaging, physical sciences, and engineering. Featuring original research contributions as well as insightful reviews for scientists interested in handling anisotropy information, it covers topics such as pertinent geometric and algebraic properties of tensors and tensor fields, challenges faced in processing and visualizing different types of data, statistical techniques for data processing, and specific applications like mapping white-matter fiber tracts in the brain. The book helps readers grasp the current challenges in the field and provides information on the techniques devised to address them. Further, it facilitates the transfer of knowledge between different disciplines in order to advance the research frontiers in these areas. This multidisciplinary book presents, in part, the outcomes of the seventh in a series of Dagstuhl seminars devoted to visualization and processing of tensor fields and higher-order descriptors, which was held in Dagstuhl, Germany, on October 28-November 2, 2018.
Download or read book Imaging fibres in the brain written by Michiel Kleinnijenhuis and published by Michiel Kleinnijenhuis. This book was released on 2014-05-19 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: In these times where connectionist accounts of brain function are gaining in popularity, there is a need for reliable tools for determining anatomical connectivity in the living human brain. The technique of choice is diffusion MRI, but it is debatable whether this tool is suitable for mapping all but the major pathways. The thesis describes my contribution to the development and validation of tools to map the connections in the human brain. To honour the giants whose shoulders we stand on, and to provide neuroanatomical background, the thesis starts with a historical essay on connectional neuroanatomy. MRI techniques are introduced, focusing on the two modalities most relevant to the topic: diffusion MRI and susceptibility MRI. The thesis starts with proposing a novel tractography method: Structure Tensor Informed Fibre Tractography (STIFT). With STIFT, the strengths of diffusion MRI (angular resolution) and susceptibility MRI (spatial resolution) are harnessed in one technique. It provides improved spatial specificity of the resulting tracts. Furthermore, in regions with complex fibre configurations, STIFT is able to distinguish between crossing and kissing fibres. Although the method might not be applicable to all tracts in the brain, STIFT is expected to be a useful addition to the tractographer’s toolkit. The focus then shifts to the cortex. Cortical diffusion imaging becomes increasingly relevant now that high resolutions can be achieved in vivo, which perhaps allows fibres to be tracked into the cortex. By imaging human tissue samples of the primary visual cortex ex vivo on preclinical MR systems, it was demonstrated that cortical diffusion properties are layer-specific. While infra- and supragranular layers show anisotropic diffusion tensors oriented radially to the cortical sheet, the stria of Gennari has low anisotropy. Additionally, the thesis has shown that cortical layers could be better distinguished with the biophysical model NODDI than with conventional diffusion models. In that investigation, diffusion MRI and histology both suggested that fibre dispersion patterns at the grey-white matter boundary vary over the folding cortical sheet. The gyral fibre configurations were investigated further by high resolution diffusion tensor imaging at 7T in vivo. A characteristic pattern of fibre anatomy of the gyrus was derived, in which we observed variations of tensor anisotropy and radiality with cortical curvature, not only in the white matter, but also within the cortex. This set of experiments has considerable implications for tractography, suggesting that (artefactual) biases towards particular locations on the cortical sheet might exist; that models should be designed to capture a variety of dispersion and crossing patterns for tracking fibres in the gyrus; and that intracortical tractography might one day be feasible. The neuroanatomical teaching tools that are described in the final part of the thesis were created by combining white matter dissection, plastination and tractography. The plastinated prosections have considerable advantages over formalin-fixed specimens because they are durable, non-toxic and easy to handle. These tools might inspire new generations of students to take up research in connectional neuroanatomy.
Download or read book Multi dimensional characterization of neuropsychiatric disorders written by Peng Wang and published by Frontiers Media SA. This book was released on 2023-01-03 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Introduction to Functional Magnetic Resonance Imaging written by Richard B. Buxton and published by Cambridge University Press. This book was released on 2009-08-27 with total page 479 pages. Available in PDF, EPUB and Kindle. Book excerpt: Functional Magnetic Resonance Imaging (fMRI) has become a standard tool for mapping the working brain's activation patterns, both in health and in disease. It is an interdisciplinary field and crosses the borders of neuroscience, psychology, psychiatry, radiology, mathematics, physics and engineering. Developments in techniques, procedures and our understanding of this field are expanding rapidly. In this second edition of Introduction to Functional Magnetic Resonance Imaging, Richard Buxton – a leading authority on fMRI – provides an invaluable guide to how fMRI works, from introducing the basic ideas and principles to the underlying physics and physiology. He covers the relationship between fMRI and other imaging techniques and includes a guide to the statistical analysis of fMRI data. This book will be useful both to the experienced radiographer, and the clinician or researcher with no previous knowledge of the technology.
Download or read book Medical Image Computing and Computer Assisted Intervention MICCAI 2010 written by Tianzi Jiang and published by Springer. This book was released on 2010-09-21 with total page 751 pages. Available in PDF, EPUB and Kindle. Book excerpt: The13thInternationalConferenceonMedicalImageComputingandComputer- Assisted Intervention, MICCAI 2010, was held in Beijing, China from 20-24 September,2010.ThevenuewastheChinaNationalConventionCenter(CNCC), China’slargestandnewestconferencecenterwith excellentfacilities andaprime location in the heart of the Olympic Green, adjacent to characteristic constr- tions like the Bird’s Nest (National Stadium) and the Water Cube (National Aquatics Center). MICCAI is the foremost international scienti?c event in the ?eld of medical image computing and computer-assisted interventions. The annual conference has a high scienti?c standard by virtue of the threshold for acceptance, and accordingly MICCAI has built up a track record of attracting leading scientists, engineersandcliniciansfromawiderangeoftechnicalandbiomedicaldisciplines. This year, we received 786 submissions, well in line with the previous two conferences in New York and London. Three program chairs and a program committee of 31 scientists, all with a recognized standing in the ?eld of the conference, were responsible for the selection of the papers. The review process was set up such that each paper was considered by the three program chairs, two program committee members, and a minimum of three external reviewers. The review process was double-blind, so the reviewers did not know the identity of the authors of the submission. After a careful evaluation procedure, in which all controversialand gray area papers were discussed individually, we arrived at a total of 251 accepted papers for MICCAI 2010, of which 45 were selected for podium presentation and 206 for poster presentation. The acceptance percentage (32%) was in keeping with that of previous MICCAI conferences. All 251 papers are included in the three MICCAI 2010 LNCS volumes.
