Download or read book Advances in Portable TRASE MRI written by Aaron R. Purchase and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic resonance imaging (MRI) is a valuable medical diagnostic technique due to its exceptional soft tissue contrast. Unfortunately, standard clinical MRI systems have limited accessibility worldwide, especially in developing countries, due to high costs, high weight, large physical dimensions, and maintenance and operating complexity. Standard MRI systems are currently inaccessible to over half the world's population. In MRI accessible regions, they are the bottlenecks of the clinical workflow due to high patient volume and low scanner numbers. Portable, low-cost, and clinically relevant MRI systems have many applications worldwide, such as alleviating accessibility issues in developing countries, rural areas, emergency rooms and medical clinics for point-of-care diagnostic imaging. In addition, mobile MRI systems may find application in ground and air ambulance services, in the military, and even beyond Earth on long-duration spaceflight. Standard MRI systems use gradients of the main magnetic field for spatial encoding, requiring expensive and bulky hardware. A novel MRI encoding method, called Transmit Array Spatial Encoding (TRASE), uses the phase of the radiofrequency (RF) field for spatial encoding signal rather than applying a switching B0 gradient. TRASE removes the need for the entire standard B0 gradient system and relaxes the main magnet's homogeneity requirement, leading to compact, lower cost, and portable MRI systems. However, the first in vivo TRASE MR wrist images, obtained in 2013, were acquired using an immobile 0.2 T magnet and with low spatial resolution due to RF hardware limitations. The objectives of this research were to (a) design and construct a new RF amplifier to improve TRASE spatial resolution; (b) design and construct a new portable magnet for TRASE to reduce the overall weight, size and cost of the system; (c) investigate magnetic field modifications allowing in vivo TRASE imaging on the constructed portable magnet; and (d) design and construct an accurate magnet rotation system that would simplify the 2D TRASE MRI hardware and acquisition technique. An RF power amplifier is an essential component in all MRI systems. Unfortunately, no commercial amplifier exists to fulfil the needs of the TRASE MRI technique, requiring a high duty cycle, high RF output power and independently controlled multi-channel capability. Therefore, we designed and constructed an RF power amplifier and tested it on the bench. In addition, the amplifier performance was tested using a 0.22 T MRI magnet with a twisted solenoid and saddle RF coil combination capable of single-axis TRASE. We showed that the amplifier is capable of sequential, dual-channel operation up to 50% duty cycle, 1 kW peak output per channel and highly stable 100 us RF pulse trains. Furthermore, high spatial resolution one-dimensional TRASE was obtained with the power amplifier to demonstrate its capability. Although TRASE resolution was improved with the new RF amplifier, the main magnet prevents portability and has high associated costs. Recently designed Halbach magnets, made of permanent magnet blocks distributed around a cylinder, used for portable MRI systems are much lighter and more compact than standard biplanar permanent or superconductive magnets. However, improved designs and manufacturing techniques aiming at a lower weight and smaller external size are of continuing interest, especially for space flight applications. In this work, we designed and constructed a 67 mT Halbach magnet with a very low aspect-ratio (length per inner diameter ~ 1:1) that produces almost identical homogeneity (11,152 ppm) as simulations (11,451 ppm) within a 12.7 cm diameter, 1 cm long cylinder region of interest (ROI). The magnet support structure was 3D printed ring-by-ring and assembled coaxially. The final magnet weight is only 25 kilograms and may be disassembled for transportation. Although the constructed Halbach magnet is compact and portable, the remaining field inhomogeneity is not well suited to slice selection using the twisted-solenoid TRASE RF coils. Therefore, the bare Halbach magnet's field requires adjustments for in-vivo TRASE MRI. As a first approach to field adjustments, a simulation study was completed to determine the feasibility and performance of various permanent magnet block configurations used as a shim array to achieve a desired target field in the ROI. Although the presented shim arrays would be inexpensive and straightforward to manufacture, excitation volumes are always present outside the ROI, requiring further field optimization or development of a new receive system to allow in-vivo TRASE. Despite the magnet's field inhomogeneity, magnet rotation allows a 2D TRASE image acquisition using two RF transmit coils rather than three, significantly reducing challenges with RF coil decoupling and reducing costs due to one less required RF amplifier channel. Accurate and high-resolution angular rotation of the Halbach magnet was achieved using an inexpensive stepper motor and driver. The proof-of-concept was verified by obtaining a set of 1D TRASE projections and using this data in a 2D TRASE reconstruction technique.
Download or read book Portable Low Field MRI Scanners written by David J. Ariando and published by Springer Nature. This book was released on with total page 340 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 Mobile NMR and MRI written by Mike Johns and published by Royal Society of Chemistry. This book was released on 2015-10-27 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book will summarise recent hardware developments, highlight the challenges facing mobile and generally low-field NMR and MRI and describe various emerging applications - some of which have commercial interest.
Download or read book Medical Imaging Systems written by Andreas Maier and published by Springer. This book was released on 2018-08-02 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book gives a complete and comprehensive introduction to the fields of medical imaging systems, as designed for a broad range of applications. The authors of the book first explain the foundations of system theory and image processing, before highlighting several modalities in a dedicated chapter. The initial focus is on modalities that are closely related to traditional camera systems such as endoscopy and microscopy. This is followed by more complex image formation processes: magnetic resonance imaging, X-ray projection imaging, computed tomography, X-ray phase-contrast imaging, nuclear imaging, ultrasound, and optical coherence tomography.
Download or read book Breast MRI written by Katja Pinker and published by Academic Press. This book was released on 2022-09-22 with total page 646 pages. Available in PDF, EPUB and Kindle. Book excerpt: Breast MRI: State of the Art and Future Directions provides a comprehensive overview of the current applications of breast MRI, including abbreviated MRI, as well as presenting technical recommendations, practical implementation and associated challenges in clinical routine. In addition, the book introduces novel MRI techniques, multimodality imaging, and advanced image processing coupled with AI, reviewing their potential for impeding and future clinical implementation. This book is a complete reference on state-of-the-art breast MRI methods suitable for MRI researchers, radiographers and clinicians. Breast cancer is one of the leading causes of death among women with early detection being the key to improved prognosis and survival. Magnetic resonance imaging (MRI) of the breast is undisputedly the most sensitive imaging method to detect cancer, with a higher detection rate than mammography, digital breast tomosynthesis, and ultrasound. Spans the whole spectrum of breast MRI, including basic imaging techniques, indications, interpretation, and the latest cutting-edge techniques Reviews multiparametric MRI and abbreviated protocols, providing an outlook on the future of this technique Discusses the predictive and prognostic value of MRI as well as the evolving field of radiomics/genomics and AI
Download or read book Fundamental and Advanced Fetal Imaging written by Beth Kline-Fath and published by Lippincott Williams & Wilkins. This book was released on 2014-09-09 with total page 2503 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effectively evaluate obstetric patients with Fundamental and Advanced Fetal Imaging: Ultrasound and MRI! Written by an impressive roster of leading fetal radiologists and maternal-fetal medicine specialists, with additional input from cardiologists, geneticists, and Doppler specialists, this state-of-the-art reference explores how to obtain the maximum information from fetal ultrasound and magnetic resonance imaging, so you can rule out pathologies with confidence – or identify them early enough to initiate the most appropriate interventions.
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 Brain and Human Body Modeling written by Sergey Makarov and published by Springer Nature. This book was released on 2019-08-27 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book describes modern applications of computational human modeling with specific emphasis in the areas of neurology and neuroelectromagnetics, depression and cancer treatments, radio-frequency studies and wireless communications. Special consideration is also given to the use of human modeling to the computational assessment of relevant regulatory and safety requirements. Readers working on applications that may expose human subjects to electromagnetic radiation will benefit from this book’s coverage of the latest developments in computational modelling and human phantom development to assess a given technology’s safety and efficacy in a timely manner. Describes construction and application of computational human models including anatomically detailed and subject specific models; Explains new practices in computational human modeling for neuroelectromagnetics, electromagnetic safety, and exposure evaluations; Includes a survey of modern applications for which computational human models are critical; Describes cellular-level interactions between the human body and electromagnetic fields.
Download or read book MRI from Picture to Proton written by Donald W. McRobbie and published by Cambridge University Press. This book was released on 2017-04-13 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: MR is a powerful modality. At its most advanced, it can be used not just to image anatomy and pathology, but to investigate organ function, to probe in vivo chemistry, and even to visualise the brain thinking. However, clinicians, technologists and scientists struggle with the study of the subject. The result is sometimes an obscurity of understanding, or a dilution of scientific truth, resulting in misconceptions. This is why MRI from Picture to Proton has achieved its reputation for practical clarity. MR is introduced as a tool, with coverage starting from the images, equipment and scanning protocols and traced back towards the underlying physics theory. With new content on quantitative MRI, MR safety, multi-band excitation, Dixon imaging, MR elastography and advanced pulse sequences, and with additional supportive materials available on the book's website, this new edition is completely revised and updated to reflect the best use of modern MR technology.
Download or read book Advances in Visual Computing written by George Bebis and published by Springer. This book was released on 2014-12-02 with total page 989 pages. Available in PDF, EPUB and Kindle. Book excerpt: The two volume set LNCS 8887 and 8888 constitutes the refereed proceedings of the 10th International Symposium on Visual Computing, ISVC 2014, held in Las Vegas, NV, USA. The 74 revised full papers and 55 poster papers presented together with 39 special track papers were carefully reviewed and selected from more than 280 submissions. The papers are organized in topical sections: Part I (LNCS 8887) comprises computational bioimaging, computer graphics; motion, tracking, feature extraction and matching, segmentation, visualization, mapping, modeling and surface reconstruction, unmanned autonomous systems, medical imaging, tracking for human activity monitoring, intelligent transportation systems, visual perception and robotic systems. Part II (LNCS 8888) comprises topics such as computational bioimaging , recognition, computer vision, applications, face processing and recognition, virtual reality, and the poster sessions.
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 Cerebral Cortex written by Edward G. Jones and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cerebral cortex, especially that part customarily designated "neocortex," is one of the hallmarks of mammalian evolution and reaches its greatest size, relatively speaking, and its widest structural diversity in the human brain. The evolution of this structure, as remarkable for the huge numbers of neurons that it contains as for the range of behaviors that it controls, has been of abiding interest to many generations of neuroscientists. Yet few theories of cortical evo lution have been proposed and none has stood the test of time. In particular, no theory has been successful in bridging the evolutionary gap that appears to exist between the pallium of non mammalian vertebrates and the neocortex of mam mals. Undoubtedly this stems in large part from the rapid divergence of non mammalian and mammalian forms and the lack of contemporary species whose telencephalic wall can be seen as having transitional characteristics. The mono treme cortex, for example, is unquestionably mammalian in organization and that of no living reptile comes close to resembling it. Yet anatomists such as Ramon y Cajal, on examining the finer details of cortical structure, were struck by the similarities in neuronal form, particularly of the pyramidal cells, and their predisposition to laminar alignment shared by representatives of all vertebrate classes.
Download or read book MRI of the Musculoskeletal System written by Thomas H. Berquist and published by Lippincott Williams & Wilkins. This book was released on 2012-04-06 with total page 1190 pages. Available in PDF, EPUB and Kindle. Book excerpt: MRI of the Musculoskeletal System, Sixth Edition, comprehensively presents all aspects of MR musculoskeletal imaging, including basic principles of interpretation, physics, and terminology before moving through a systematic presentation of disease states in each anatomic region of the body. Its well-deserved reputation can be attributed to its clarity, simplicity, and comprehensiveness. The Sixth Edition features many updates, including: New pulse sequences and artifacts in the basics chapters Over 3,000 high-quality images including new anatomy drawings and images FREE access to a companion web site featuring full text as well as an interactive anatomy quiz with matching labels of over 300 images.
Download or read book MRI Made Easy written by Govind B Chavhan and published by JP Medical Ltd. This book was released on 2013-01-30 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic resonance imaging (MRI) is a type of scan used to diagnose health conditions that affect organs, tissue and bone. MRI scanners use strong magnetic fields and radio waves to produce detailed images of the inside of the body. Divided into two sections, this concise guide introduces radiology trainees to the principles, sequences and interpretation of MRI. The first section describes the basic principles, instrumentation and interpretation of MRI, whilst the second section discusses the higher applications of the technique. Authored by Canadian radiologist Govind Chavhan, this second edition includes 250 images and illustrations, as well as a photo CD, to assist trainees with learning. Key points New edition introducing radiology trainees to principles, sequences and interpretation of MRI Authored by Canadian radiology specialist Features 250 images and illustrations Includes photo CD First edition published in 2007
Download or read book Portable Spectroscopy and Spectrometry Applications written by Richard A. Crocombe and published by John Wiley & Sons. This book was released on 2021-04-28 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most comprehensive resource available on the many applications of portable spectrometers, including material not found in any other published work Portable Spectroscopy and Spectrometry: Volume Two is an authoritative and up-to-date compendium of the diverse applications for portable spectrometers across numerous disciplines. Whereas Volume One focuses on the specific technologies of the portable spectrometers themselves, Volume Two explores the use of portable instruments in wide range of fields, including pharmaceutical development, clinical research, food analysis, forensic science, geology, astrobiology, cultural heritage and archaeology. Volume Two features contributions by a multidisciplinary team of experts with hands-on experience using portable instruments in their respective areas of expertise. Organized both by instrumentation type and by scientific or technical discipline, 21 detailed chapters cover various applications of portable ion mobility spectrometry (IMS), infrared and near-infrared (NIR) spectroscopy, Raman and x-ray fluorescence (XRF) spectroscopy, smartphone spectroscopy, and many others. Filling a significant gap in literature on the subject, the second volume of Portable Spectroscopy and Spectrometry: Features a significant amount of content published for the first time, or not available in existing literature Brings together work by authors with assorted backgrounds and fields of study Discusses the central role of applications in portable instrument development Covers the algorithms, calibrations, and libraries that are of critical importance to successful applications of portable instruments Includes chapters on portable spectroscopy applications in areas such as the military, agriculture and feed, hazardous materials (HazMat), art conservation, and environmental science Portable Spectroscopy and Spectrometry: Volume Two is an indispensable resource for developers of portable instruments in universities, research institutes, instrument companies, civilian and government purchasers, trainers, operators of portable instruments, and educators and students in portable spectroscopy courses.
Download or read book Visualizing Chemistry written by National Research Council and published by National Academies Press. This book was released on 2006-06-01 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientists and engineers have long relied on the power of imaging techniques to help see objects invisible to the naked eye, and thus, to advance scientific knowledge. These experts are constantly pushing the limits of technology in pursuit of chemical imagingâ€"the ability to visualize molecular structures and chemical composition in time and space as actual events unfoldâ€"from the smallest dimension of a biological system to the widest expanse of a distant galaxy. Chemical imaging has a variety of applications for almost every facet of our daily lives, ranging from medical diagnosis and treatment to the study and design of material properties in new products. In addition to highlighting advances in chemical imaging that could have the greatest impact on critical problems in science and technology, Visualizing Chemistry reviews the current state of chemical imaging technology, identifies promising future developments and their applications, and suggests a research and educational agenda to enable breakthrough improvements.
