Download or read book D veloppement de nouvelles s quences d IRM de diffusion d di es la neuro imagerie written by Renaud Nicolas and published by . This book was released on 2012 with total page 601 pages. Available in PDF, EPUB and Kindle. Book excerpt: Le sujet de cette thèse est dédié au développement d'une technique, l'IRM de diffusion, qui permet d'obtenir des images de propriétés micro-structurelles (inférieures à la taille du pixel obtenu par IRM) des milieux biologique, et à son application à l'étude du cerveau. La capacité de cette technique à révéler des modifications précoces de changement micro-structuraux qui sont associés à des modifications métaboliques énergétiques complexes en a fait une méthode de référence pour détecter précocement certaines pathologies focales telles les Accidents Vasculaires Cérébraux Ischémiques. Le lecteur pourra trouver dans cette thèse une introduction complète aux phénomènes physiques de la diffusion brownienne dans les milieux biologiques, de l'IRM et de la RMN de diffusion ainsi qu'une synthèse originale sur les origine biologiques et biophysiques des modifications de Coefficient de Diffusion Apparent observés dans l'ischémie. Afin d'étendre le domaine de l'IRM de diffusion des phénomènes ischémiques focaux (étudiés expérimentalement sur l'homme et l'animal) aux pathologies non focales, l'étude de la déviation à la diffusion gaussienne de l'eau dans les tissus biologiques a été étudiée du point de vue bibliographique et expérimental. Les méthodologies pratiques permettant de traiter et de préparer les images de diffusion pour l'étude des diffusion non gaussienne ainsi que les corrections d'artefacts nécessaires y sont soigneusement décrites. Ceci a pu donner lieu à une étude des modèles de diffusion non gaussienne en tant que problématique inverse et à des applications dans la détection de la Maladie d'Alzheimer, caractérisée par des lésions peu focales et microscopiques. Enfin, nous avons mis au point trois approches originales de développement technologiques de séquences d'IRM de diffusion ainsi que les traitements d'images associés nécessaires à leur exploitation. Le premier développement inclut les mesures de diffusion non gaussienne avec variation des temps de diffusion appliquée à l'imagerie à 4.7 et 7 T. Le second a consisté à mettre en place et tester à 3 T des séquences combinées de diffusion et de transfert d'aimantation permettant d'apporter des indications additionnelles sur la nature de l'eau sondée par l'IRM de diffusion. La troisième approche a consisté à développer à 3 T une méthodologie d'IRM fonctionnelle du tenseur de diffusion destinée à expérimenter les postulats biologiques résumés dans la première partie de cette thèse concernant le rôle potentiel de l'eau et de sa biologie dans les phénomènes d'activation cérébrales fonctionnelles. Au fil des validations, les hypothèses sur les micro-structures des milieux biologiques sont testées et affinées par différentes approches in vivo, ex vivo et in silico, afin d'appliquer les avancées physiques récentes en l'IRM de diffusion à la détection médicale des pathologies focales et non focales et interpréter celle-ci.
Download or read book Acquisition Compress e en IRM de Diffusion written by Sylvain Merlet and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is dedicated to the development of new acquisition and processing methods in diffusion MRI (dMRI) to characterize the diffusion of water molecules in white matter fiber bundles at the scale of a voxel. In particular, we focus our attention on the accurate recovery of the Ensemble Average Propagator (EAP), which represents the full 3D displacement of water molecule diffusion. Diffusion models such that the Diffusion Tensor or the Orientation Distribution Function (ODF) are largely used in the dMRI community in order to quantify water molecule diffusion. These models are partial EAP representations and have been developed due to the small number of measurement required for their estimations. It is thus of utmost importance to be able to accurately compute the EAP and order to acquire a better understanding of the brain mechanisms and to improve the diagnosis of neurological disorders. Estimating the full 3D EAP requires the acquisition of many diffusion images sensitized todifferent orientations in the q-space, which render the estimation of the EAP impossible in most of the clinical dMRI scanner. A surge of interest has been seen in order to decrease this time for acquisition. Some works focus on the development of new and efficient acquisition sequences. In this thesis, we use sparse coding techniques, and in particular Compressive Sensing (CS) to accelerate the computation of the EAP. Multiple aspects of the CS theory and its application to dMRI are presented in this thesis.
Download or read book Diffusion Weighted MR Imaging of the Brain written by Toshio Moritani and published by Springer Science & Business Media. This book was released on 2009-08-03 with total page 411 pages. Available in PDF, EPUB and Kindle. Book excerpt: Few advances in MR imaging have had the impact degenerative neurologic disorders, white matter d- that dif usion-weighted (DW) imaging has had in the eases, toxic/metabolic disorders, and tumors. As one evaluation of brain. From the time of the early de- can easily see from the table of contents, the authors scriptions by LeBihan and colleagues of the ability have systematically covered all major areas of neu- to image and measure the micromovement of water radiology. T is will allow cross-referencing to pr- molecules in the brain to the present time, dif usion lematic cases which one may encounter. Additionally, imaging and its derivatives have made an impact in knowledge of what represents a normal adult brain the evaluation of multiple disease processes, primar- and a normal developing brain along with an exp- ily in ischemia, but also in other conditions of the nation of artifacts seen in DW imaging makes this a brain. In most medical centers dif usion imaging is valuable book. It is noteworthy that the authors have no longer considered a sequence to be used in spe- chosen to abundantly illustrate the clinical material, cial circumstances, but rather it is employed as part drawing on pathologic correlations in a number of of routine MR imaging of the brain. Because the in- areas.
Download or read book Diffusion MRI of Human Spine and Kidney written by Mario Ries and published by . This book was released on 2001 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: La mesure locale de la constante de diffusion fournit des informations sur l'environ-nement microscopique cellulaire des molécules d'eau. L'information sur la microstructure issue des images IRM de diffusion peut servir à déterminer la structure des fibres neu-ronales. Bien que cette possibilité soit très prometteuse pour le diagnostic, son applica-tion en routine clinique a été jusqu'à ce jour rendue difficile par le fait que la géométrie complexe des structures fibreuses du cerveau complique le traitement des données et l'interprétation des résultats. Le travail présenté dans cet ouvrage a été inspiré par l'idée séduisante d'utiliser les expériences de diffusion pour sonder la microstructure neuronale dans des systèmes neuronaux à forte symmétrie, comme la moelle. Malheureusement, l'IRM de diffusion hors du cerveau est assez difficile à réaliser à cause de la forte sensi-bilité de la technique aux mouvements. D'autre part, l'utilisation de séquences d'imagerie rapide avec de tels systèmes nécessite une approche méthodologique soignée. Parce que l'analyse de systèmes neuronaux organisés offre un grand potentiel en terme de diagnostic d'affections qui induisent des changements pathologiques perturbant cette symmétrie, une étude clinique a été initiée dans le but de tester cette hypothèse. De plus, le développement de séquences d'imagerie et des techniques de traitement de données inhérentes aux mesures de diffusion sur la moelle nous a permis d'appliquer les méthodes d'imagerie paramétrique par IRM à des systèmes anatomiques plus compliqués, comme le rein. Dans ce cas précis, le temps d'imagerie court, ainsi que l'influence des mouvements respiratoires et des artéfacts de susceptibilité ont poussé les méthodes d'imagerie dans leurs derniers retranchements.
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 Tensor Imaging written by Bram Stieltjes and published by Springer Science & Business Media. This book was released on 2013-02-14 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffusion Tensor Imaging (DTI) is a variation of diffusion-weighed imaging. Particularly in the neurosciences, this technique has gained tremendous momentum in the past decade, both from a technical point of view as well as in its applications. DTI is mainly used in neurological diagnosis and psychiatric and neurologic research, e.g. in order to locate brain tumors and depict their invasivity. DTI offers a unique in-vivo insight into the three-dimensional structure of the human central nervous system. While easy interpretation and evaluation is often hampered by the complexity of both the technique and neuroanatomy, this atlas helps you recognize every one of the important structures rapidly and unambiguously. In the introduction, this atlas provides a concise outline of the evolution of diffusion imaging and describes its potential applications. In the core part of the atlas, the neuroanatomically important structures are clearly labeled both on DTI-derived color maps and conventional MRI. Complex fiber architecture is illustrated schematically and described concisely in textboxes directly on the relevant page. In the final part of the atlas, a straightforward, step-by-step approach for the three-dimensional reconstruction of the most prominent fiber structures is given, and potential pitfalls are indicated. The atlas aims at neuroscientists, neuoanatomists, neurologists, psychiatrists, clinical psychologists, physicists, and computer scientists. For advanced users, the atlas may serve as a reference work, while students and scientists are thoroughly introduced in DTI.
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 Diffusion Weighted MR Imaging of the Brain written by T. Moritani and published by Springer Science & Business Media. This book was released on 2005-08-11 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffusion-weighted MR imaging is widely accepted as a means to identify stroke, thus enabling rapid and effective treatment. Over the past four years, these expert authors have presented over 30 exhibits and scientific reports on diffusion-weighted imaging at the RSNA and the American Society of Neuroradiology (ASNR), and more than 10 of these presentations have been recognized by specific awards. Diffusion-Weighted MR Imaging of the Brain’s chapters range from basic principles to interpretation of diffusion-weighted MR imaging and specific disease. This is a valuable reference for radiologists, neurologists, neurosurgeons as well as residents, fellows, radiology technologists.
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 Trait d imagerie m dicale Volume 1 2e d written by NAHUM Henri and published by Lavoisier. This book was released on 2013-12-12 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exhaustive et très richement illustrée, cette deuxième édition entièrement en couleur aborde de manière toujours claire et précise les méthodes et les résultats de l’imagerie de l’ensemble du corps humain. Chaque section présente de façon systématique : Les différentes techniques d’imagerie disponibles, des plus classiques au plus innovantes. Les principales stratégies diagnostiques pour toutes les pathologies de la région explorée. L’ensemble des chapitres a été actualisé et les chapitres de neurocardiologie et d'imagerie cardiovasculaire ont été totalement réécrits pour tenir compte des nouveaux apports de l’imagerie et des plus récents développements technologiques.
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 Weighted and Diffusion Tensor Imaging written by Claudia Leite and published by Thieme. This book was released on 2015-12-16 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffusion-weighted imaging (DWI) is an integral part of routine neuroimaging, used nearly universally in brain MRIs, and more recently for the spine, spinal cord, and head and neck. DWI provides clinically relevant information on conditions including stroke, infection, and neoplasms. Diffusion tensor imaging (DTI) is a powerful, newer technique with the potential for multiple protocols, including the diagnosis of mild traumatic brain injury and psychiatric disorders. Written by leading authorities in neuroradiology and radiology, Diffusion Weighted and Diffusion Tensor Imaging: A Clinical Guide provides key points and summaries on the concepts and applications required for proper implementation and interpretation of DWI and DTI. Key Features: More than 600 high-quality illustrations Protocols and applications from early childhood to older adulthood Methods to differentiate normal versus pathological states Brain edema pathophysiology and use of DWI to distinguish between cytotoxic and vasogenic edema Utilization of DWI and DTI to diagnose trauma, white matter disease, tumors, cerebrovascular disease, and head, neck, and spine disorders This concise handbook is an invaluable resource for neuro-radiologists and radiologists, as well as fellows and residents in these disciplines. With the expanding use of these procedures, neuroscientists, neurologists, neurosurgeons, and psychiatrists will also find it indispensable.
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 2020-08-17 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 Diffusion in Nanoporous Materials 2 Volumes written by Jörg Kärger and published by John Wiley & Sons. This book was released on 2012-10-29 with total page 932 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atoms and molecules in all states of matter are subject to continuous irregular movement. This process, referred to as diffusion, is among the most general and basic phenomena in nature and determines the performance of many technological processes. This book provides an introduction to the fascinating world of diffusion in microporous solids. Jointly written by three well-known researchers in this field, it presents a coherent treatise, rather than a compilation of separate review articles, covering the theoretical fundamentals, molecular modeling, experimental observation and technical applications. Based on the book Diffusion in Zeolites and other Microporous Solids, originally published in 1992, it illustrates the remarkable speed with which this field has developed since that time. Specific topics include: new families of nanoporous materials, micro-imaging and single-particle tracking, direct monitoring of transient profiles by interference microscopy, single-file diffusion and new approaches to molecular modeling.
Download or read book Diffusion Weighted MR Imaging of the Brain Head and Neck and Spine written by Toshio Moritani and published by Springer Nature. This book was released on 2021-05-30 with total page 928 pages. Available in PDF, EPUB and Kindle. Book excerpt: This richly illustrated book, now in an updated and extended third edition, systematically covers the use of diffusion-weighted (DW) MR imaging in all major areas of neuroradiology, including imaging of the head and neck and the spine as well as the brain. The authors guide the reader from the basic principles of DW imaging through to the use of cutting-edge diffusion sequences such as diffusion tensor (DTI) and kurtosis (DKI), fiber tractography, high b value, intravoxel incoherent motion (IVIM), neurite orientation dispersion and density imaging (NODDI), and oscillating gradient spin echo (OGSE). Pathology, pathophysiology, and patient management and treatment are all thoroughly discussed. Since the early descriptions by LeBihan and colleagues of the ability to image and measure the micromovement of water molecules in the brain, diffusion imaging and its derivatives have contributed ever more significantly to the evaluation of multiple disease processes. In comprehensively describing the state of the art in the field, this book will be of high value not only for those who deal routinely with neuro-MR imaging but also for readers who wish to establish a sound basis for understanding diffusion images in the hope of extending these principles into more exotic areas of neuroimaging.
Download or read book ETUDE DE FAISABILITE DES SEQUENCES DE DIFFUSION ET DE PERFUSION EN IRM ENCEPHALIQUE written by PIERRE.. GUILLEM and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
