Download or read book Advanced Methods for Diffusion MRI Data Analysis and Their Application to the Healthy Ageing Brain written by Rafael Neto Henriques and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced analysis of diffusion MRI data written by Xuan Gu and published by Linköping University Electronic Press. This book was released on 2019-11-19 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffusion magnetic resonance imaging (diffusion MRI) is a non-invasive imaging modality which can measure diffusion of water molecules, by making the MRI acquisition sensitive to diffusion. Diffusion MRI provides unique possibilities to study structural connectivity of the human brain, e.g. how the white matter connects different parts of the brain. Diffusion MRI enables a range of tools that permit qualitative and quantitative assessments of many neurological disorders, such as stroke and Parkinson. This thesis introduces novel methods for diffusion MRI data analysis. Prior to estimating a diffusion model in each location (voxel) of the brain, the diffusion data needs to be preprocessed to correct for geometric distortions and head motion. A deep learning approach to synthesize diffusion scalar maps from a T1-weighted MR image is proposed, and it is shown that the distortion-free synthesized images can be used for distortion correction. An evaluation, involving both simulated data and real data, of six methods for susceptibility distortion correction is also presented in this thesis. A common problem in diffusion MRI is to estimate the uncertainty of a diffusion model. An empirical evaluation of tractography, a technique that permits reconstruction of white matter pathways in the human brain, is presented in this thesis. The evaluation is based on analyzing 32 diffusion datasets from a single healthy subject, to study how reliable tractography is. In most cases only a single dataset is available for each subject. This thesis presents methods based on frequentistic (bootstrap) as well as Bayesian inference, which can provide uncertainty estimates when only a single dataset is available. These uncertainty measures can then, for example, be used in a group analysis to downweight subjects with a higher uncertainty.
Download or read book Diffusion Tensor Imaging written by Wim Van Hecke and published by Springer. This book was released on 2015-12-14 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an overview of the practical aspects of diffusion tensor imaging (DTI), from understanding the basis of the technique through selection of the right protocols, trouble-shooting data quality, and analyzing DTI data optimally. DTI is a non-invasive magnetic resonance imaging (MRI) technique for visualizing and quantifying tissue microstructure based on diffusion. The book discusses the theoretical background underlying DTI and advanced techniques based on higher-order models and multi-shell diffusion imaging. It covers the practical implementation of DTI; derivation of information from DTI data; and a range of clinical applications, including neurosurgical planning and the assessment of brain tumors. Its practical utility is enhanced by decision schemes and a fully annotated DTI brain atlas, including color fractional anisotropy maps and 3D tractography reconstructions of major white matter fiber bundles. Featuring contributions from leading specialists in the field of DTI, Diffusion Tensor Imaging: A Practical Handbook is a valuable resource for radiologists, neuroradiologists, MRI technicians and clinicians.
Download or read book Diffusion MRI written by Heidi Johansen-Berg and published by Academic Press. This book was released on 2013-11-04 with total page 627 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffusion MRI remains the most comprehensive reference for understanding this rapidly evolving and powerful technology and is an essential handbook for designing, analyzing, and interpreting diffusion MR experiments. Diffusion imaging provides a unique window on human brain anatomy. This non-invasive technique continues to grow in popularity as a way to study brain pathways that could never before be investigated in vivo. This book covers the fundamental theory of diffusion imaging, discusses its most promising applications to basic and clinical neuroscience, and introduces cutting-edge methodological developments that will shape the field in coming years. Written by leading experts in the field, it places the exciting new results emerging from diffusion imaging in the context of classical anatomical techniques to show where diffusion studies might offer unique insights and where potential limitations lie. Fully revised and updated edition of the first comprehensive reference on a powerful technique in brain imaging Covers all aspects of a diffusion MRI study from acquisition through analysis to interpretation, and from fundamental theory to cutting-edge developments New chapters covering connectomics, advanced diffusion acquisition, artifact removal, and applications to the neonatal brain Provides practical advice on running an experiment Includes discussion of applications in psychiatry, neurology, neurosurgery, and basic neuroscience Full color throughout
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 Analysis Methods for the Study of Multimodal MRI and Individual Variability in Brain Structure and Function written by Mohammed Patel and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The past two decades have seen significant advances in the field of neuroimaging. Progress in magnetic resonance imaging (MRI) and increasing availability of large scale public datasets have made it more common for researchers to study the brain via multiple measures of brain structure and function. These rich datasets are accompanied by in depth behavioural phenotyping as well, so that researchers may relate neuroanatomical measurements to cognitive function. This offers a unique and exciting opportunity, but necessitates corresponding advances in analysis methods. Traditional univariate and single modality approaches suffer from limitations in the context of current large-scale multivariate analyses. The main contribution of this thesis is the integration of multimodal MRI data into a novel analytical framework which, using non-negative matrix factorization, enables the study of inter-individual variation and its relation to behavioural data. Chapter 3 presents a novel analytical framework for parcellating brain anatomy based on multimodal MRI data. Non-negative matrix factorization (NMF) is applied to structural and diffusion MRI data of the human hippocampus in a sample of healthy young adults. This approach identifies four distinct hippocampus subregions, each displaying different anatomical properties. Additionally, we perform a multivariate brain-behaviour analysis to show that individual variation within each of the four regions demonstrates strong relationships to a wide variety of behavioural and demographic features. Chapter 4 studies the relationship between cortical anatomy and longitudinal cognitive trajectories. Here we study a unique sample of healthy elderly individuals from Whitehall II Imaging Sub Study, with structural and diffusion MRI data collected in late life and cognitive performance assessed from mid-life to late life at 5 year intervals. Applying the methods developed in Chapter 3, we identify two latent dimensions relating late life cortical anatomy and mid to late life cognitive trajectories. Each contains a mixture of maintenance and decline, suggesting a heterogenous relationship between brain and behaviour. Finally, we find that mid-life features are the dominant factor in determining late life phenotypes which adds substantial evidence towards using a full lifespan approach when studying aging. Chapter 5 studies structure-function relationships in the brain. Previous studies have shown that regions of the brain with similar structural properties are likely to share similar functional activity properties. We applied NMF to structural and functional measurements in a sample of healthy young adults to show that previous group level findings had indeed obscured individual level variability. This approach shows that in certain regions, some but not all individuals display strong structure-function coupling. This finding demonstrates how the NMF framework used in this thesis can go beyond group level findings to highlight individual variability. The techniques proposed in this thesis are adaptable to a variety of neuroimaging modalities and data types, and will thus provide advancements for future works to fully capitalize on the growth of the neuroimaging field to build towards individual level applications"--
Download or read book Advanced Magnetic Resonance Imaging Techniques in the Diagnosis of Alzheimer s Disease Ad and Evaluation of Ad Pathogenesis in an Aging Brain written by Ka-Fung Henry Mak 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, "Advanced Magnetic Resonance Imaging Techniques in the Diagnosis of Alzheimer's Disease (AD), and Evaluation of AD Pathogenesis in an Aging Brain" by Ka-fung, Henry, Mak, 麥嘉豐, 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: Background: The impact of Alzheimer's disease (AD) on society's resources and manpower has been forecasted for more than a decade, and recent statistics across the globe reveal that it is forthcoming. Pioneering work since 1980s confirmed the pathological hallmarks of the disease, such as neuritic plaques, neurofibrillary tangles, amyloid-β peptides, and microtubule-associated tau proteins. There are many gaps in the full appraisal of this complex disease, which possibly begins early in life in susceptible individuals and present at different severity and speed. In current thesis, advanced magnetic resonance imaging (MRI) techniques were evaluated for their efficacy in diagnosis, and in exploring AD pathogenesis. Methods: In MRI volumetry/perfusion and diffusion studies, 20 and 18 AD subjects (different cohorts) were recruited respectively from the memory clinic of a University hospital, while 20 and 18 cognitively normal older adults (CN) were recruited respectively from elderly centers, community and university volunteers, as well as 17 young adults in the diffusion study. In MR Spectroscopy (MRS), 30 healthy volunteers of 3 different age ranges (20-39, 40-59, 60-89) were recruited. All studies were performed using a 3-tesla MRI scanner. For MRI volumetry, a standardized T1-weighted 3D volumetric Fast Field Echo sequence, and for pulsatile Arterial Spin Labeling (ASL), a Look-Locker-based echo-planar imaging sequence was employed. Single-shot echo-planar diffusion weighted imaging was used to examine white matter (WM) integrity; diffusion sensitizing gradients (b = 800 s/mm2) applied in 16 directions, and one additional image without diffusion gradient (b0 = 0 s/mm2). Single voxel MRS was performed in the limbic regions, with point resolved spectroscopy for volume selection and excitation for water suppression. Results: Voxel Based Morphometry with Diffeomorphic Anatomical Registration using Exponentiated Lie algebra and standard registration has similarly high efficacies as manual hippocampal volumetry in discriminating AD from CN. Using pulsatile ASL, we found impairment of hemodynamic parameters other than cerebral blood flow (CBF) in moderate AD, indicative of underlying vascular abnormality. Combined MR hippocampal volumetry and ASL CBF was superior to single measure in AD diagnosis. Using diffusion tensor imaging (DTI) techniques, parallel evidence of anterior WM disintegrity in normal elderly, and more extensively in the AD was found. AD showed further loss of WM integrity in the posterior brain regions, and such WM disintegrity may result from demyelination. In aging, we found increased choline and creatine, and N-acetyl-aspartate in cingulate gyri, which might suggest glial proliferation and neuronal hypertrophy respectively. Discussion: A 'one-stop-shop' study combining structural and perfusion MRI has improved efficacy in discriminating AD from CN. DTI showed possible WM retrogenesis in normal aging and AD, although ischemic effect on WM cannot be ruled out. Our MRS study highlighted metabolic changes with age, which could be compensatory to an increased energy demand coupled with a lower CBF. Neuroimaging is likely to have a great impact on early diagnosis of AD, which will benefit patient care, prognostication and future therapy. Hopefully, insights into the physiol
Download or read book Translational Research in Traumatic Brain Injury written by Daniel Laskowitz and published by CRC Press. This book was released on 2016-04-21 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traumatic brain injury (TBI) remains a significant source of death and permanent disability, contributing to nearly one-third of all injury related deaths in the United States and exacting a profound personal and economic toll. Despite the increased resources that have recently been brought to bear to improve our understanding of TBI, the developme
Download or read book Diffusion MRI written by Heidi Johansen-Berg and published by Academic Press. This book was released on 2009-04-28 with total page 507 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffusion MRI is a magnetic resonance imaging (MRI) method that produces in vivo images of biological tissues weighted with the local microstructural characteristics of water diffusion, providing an effective means of visualizing functional connectivities in the nervous system. This book is the first comprehensive reference promoting the understanding of this rapidly evolving and powerful technology and providing the essential handbook for designing, analyzing or interpreting diffusion MR experiments.The book presents diffusion imaging in the context of well-established, classical experimental techniques, so that readers will be able to assess the scope and limitations of the new imaging technology with respect to techniques available previously. All chapters are written by leading international experts and cover methodology, validation of the imaging technology, application of diffusion imaging to the study of variation and development of normal brain anatomy, and disruption to the white matter in neurological disease or psychiatric disorder. • Discusses all aspects of a diffusion MRI study from acquisition, through analysis, to interpretation, providing an essential reference text for scientists designing or interpreting diffusion MR experiments• Practical advice on running an experiment• Full color throughout
Download or read book Cognitive Changes and the Aging Brain written by Kenneth M. Heilman and published by Cambridge University Press. This book was released on 2019-12-05 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the changes in the brain and in cognitive functions that occur with aging in the absence of a neurological, psychiatric, or medical disease. It discusses aging-related changes in many brain functions, including memory, language, sensory perception, motor function, creativity, attention, executive functions, emotions and mood. The neural mechanisms that may account for specific aging-related changes in cognition, perception and behavior are explored, as well as the means by which aging-related cognitive decrements can be managed and possibly ameliorated. Consequently, this book will be of value to clinicians, including neurologists, psychiatrists, geriatricians, primary care physicians, psychologists and speech-language pathologists. In addition, researchers and graduate students who want to learn about the aging brain will find this an indispensable guide.
Download or read book Advanced Neuroimaging Methods in Brain Disorders written by Jurong Ding and published by Frontiers Media SA. This book was released on 2022-05-05 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Handbook of MRI Pulse Sequences written by Matt A. Bernstein and published by Elsevier. This book was released on 2004-09-21 with total page 1041 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic Resonance Imaging (MRI) is among the most important medical imaging techniques available today. There is an installed base of approximately 15,000 MRI scanners worldwide. Each of these scanners is capable of running many different "pulse sequences", which are governed by physics and engineering principles, and implemented by software programs that control the MRI hardware. To utilize an MRI scanner to the fullest extent, a conceptual understanding of its pulse sequences is crucial. Handbook of MRI Pulse Sequences offers a complete guide that can help the scientists, engineers, clinicians, and technologists in the field of MRI understand and better employ their scanner. Explains pulse sequences, their components, and the associated image reconstruction methods commonly used in MRI Provides self-contained sections for individual techniques Can be used as a quick reference guide or as a resource for deeper study Includes both non-mathematical and mathematical descriptions Contains numerous figures, tables, references, and worked example problems
Download or read book Neuroimaging in Dementia written by Frederik Barkhof and published by Springer Science & Business Media. This book was released on 2011-02-11 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: This up-to-date, superbly illustrated book is a practical guide to the effective use of neuroimaging in the patient with cognitive decline. It sets out the key clinical and imaging features of the various causes of dementia and directs the reader from clinical presentation to neuroimaging and on to an accurate diagnosis whenever possible. After an introductory chapter on the clinical background, the available "toolbox" of structural and functional neuroimaging techniques is reviewed in detail, including CT, MRI and advanced MR techniques, SPECT and PET, and image analysis methods. The imaging findings in normal ageing are then discussed, followed by a series of chapters that carefully present and analyze the key findings in patients with dementias. Throughout, a practical approach is adopted, geared specifically to the needs of clinicians (neurologists, radiologists, psychiatrists, geriatricians) working in the field of dementia, for whom this book will prove an invaluable resource.
Download or read book Advanced Diffusion Encoding Methods in MRI written by Daniel Topgaard and published by Royal Society of Chemistry. This book was released on 2020-08-06 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: The medical MRI community is by far the largest user of diffusion NMR techniques and this book captures the current surge of methods and provides a primary source to aid adoption in this field. There is a trend to adapting the more advanced diffusion encoding sequences developed by NMR researchers within the fields of porous media, chemical engineering, and colloid science to medical research. Recently published papers indicate great potential for improved diagnosis of the numerous pathological conditions associated with changes of tissue microstructure that are invisible to conventional diffusion MRI. This book disseminates these recent developments to the wider community of MRI researchers and clinicians. The chapters cover the theoretical basis, hardware and pulse sequences, data analysis and validation, and recent applications aimed at promoting further growth in the field. This is a fast moving field and chapters are written by key MRI scientists that have contributed to the successful translation of the advanced diffusion NMR methods to the context of medical MRI, from global locations.
Download or read book Clinical Functional MRI written by Christoph Stippich and published by Springer. This book was released on 2015-02-27 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second, revised edition of this successful textbook provides an up-to-date description of the use of preoperative fMRI in patients with brain tumors and epilepsies. State of the art fMRI procedures are presented, with detailed consideration of practical aspects, imaging and data processing, normal and pathological findings, and diagnostic possibilities and limitations. Relevant information on brain physiology, functional neuroanatomy, imaging technique, and methodology is provided by recognized experts in these fields. Compared with the first edition, chapters have been updated to reflect the latest developments and in particular the current use of diffusion tensor imaging (DTI) and resting-state fMRI. Entirely new chapters are included on resting-state presurgical fMRI and the role of DTI and tractography in brain tumor surgery. Further chapters address multimodality functional neuroimaging, brain plasticity, and pitfalls, tips, and tricks.
