Download or read book MRI Optimization written by Peggy Woodward and published by McGraw-Hill Professional Publishing. This book was released on 1997 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Compressed Sensing Magnetic Resonance Image Reconstruction Algorithms written by Bhabesh Deka and published by Springer. This book was released on 2018-12-29 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive review of the recent developments in fast L1-norm regularization-based compressed sensing (CS) magnetic resonance image reconstruction algorithms. Compressed sensing magnetic resonance imaging (CS-MRI) is able to reduce the scan time of MRI considerably as it is possible to reconstruct MR images from only a few measurements in the k-space; far below the requirements of the Nyquist sampling rate. L1-norm-based regularization problems can be solved efficiently using the state-of-the-art convex optimization techniques, which in general outperform the greedy techniques in terms of quality of reconstructions. Recently, fast convex optimization based reconstruction algorithms have been developed which are also able to achieve the benchmarks for the use of CS-MRI in clinical practice. This book enables graduate students, researchers, and medical practitioners working in the field of medical image processing, particularly in MRI to understand the need for the CS in MRI, and thereby how it could revolutionize the soft tissue imaging to benefit healthcare technology without making major changes in the existing scanner hardware. It would be particularly useful for researchers who have just entered into the exciting field of CS-MRI and would like to quickly go through the developments to date without diving into the detailed mathematical analysis. Finally, it also discusses recent trends and future research directions for implementation of CS-MRI in clinical practice, particularly in Bio- and Neuro-informatics applications.
Download or read book Clinical Low Field Strength Magnetic Resonance Imaging written by Hans-Martin Klein and published by Springer. This book was released on 2015-10-03 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers all aspects of low field MRI, describing its advantages, problems and prerequisites. Individual chapters are devoted to site planning, safety considerations, coils, imaging technique, image quality optimization, the imaging of different anatomic regions and likely future developments. The factors that must be borne in mind when selecting a low field system are clearly identified and detailed attention is paid to the applications for which such a system is adequate. The focus on high field systems has led to a situation where only a few systems with field strengths lower than 0.5 T survive. Some of these systems possess high field features such as multichannel coils and strong gradients; furthermore, sequence technology and image processing techniques taken from higher field strength systems have resulted in impressive imaging capabilities. While 1.5-T systems will probably continue to remain the standard, low field systems offer advantages such as the feasibility of dynamic joint examinations, improvement of T1 contrast, reduction of “missile effects” and decreased radiofrequency exposure. Low field strength MRI consequently has the potential to contribute to optimal patient management and given comparable image quality, its application may become an issue of patient safety. This book will be an invaluable asset to all who are involved in planning and/or running a low field strength MRI facility.
Download or read book MRI in Practice written by Catherine Westbrook and published by John Wiley & Sons. This book was released on 2018-08-01 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: MRI in Practice continues to be the number one reference book and study guide for the registry review examination for MRI offered by the American Registry for Radiologic Technologists (ARRT). This latest edition offers in-depth chapters covering all core areas, including: basic principles, image weighting and contrast, spin and gradient echo pulse sequences, spatial encoding, k-space, protocol optimization, artefacts, instrumentation, and MRI safety. The leading MRI reference book and study guide. Now with a greater focus on the physics behind MRI. Offers, for the first time, equations and their explanations and scan tips. Brand new chapters on MRI equipment, vascular imaging and safety. Presented in full color, with additional illustrations and high-quality MRI images to aid understanding. Includes refined, updated and expanded content throughout, along with more learning tips and practical applications. Features a new glossary. MRI in Practice is an important text for radiographers, technologists, radiology residents, radiologists, and other students and professionals working within imaging, including medical physicists and nurses.
Download or read book Optimization Algorithms in Compressive Sensing CS Sparse Magnetic Resonance Imaging MRI written by Viliyana Takeva-Velkova and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Compressed Sensing Magnetic Resonance Image Reconstruction Algorithms written by Sumit Datta and published by . This book was released on 2019 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive review of the recent developments in fast L1-norm regularization-based compressed sensing (CS) magnetic resonance image reconstruction algorithms. Compressed sensing magnetic resonance imaging (CS-MRI) is able to reduce the scan time of MRI considerably as it is possible to reconstruct MR images from only a few measurements in the k-space; far below the requirements of the Nyquist sampling rate. L1-norm-based regularization problems can be solved efficiently using the state-of-the-art convex optimization techniques, which in general outperform the greedy techniques in terms of quality of reconstructions. Recently, fast convex optimization based reconstruction algorithms have been developed which are also able to achieve the benchmarks for the use of CS-MRI in clinical practice. This book enables graduate students, researchers, and medical practitioners working in the field of medical image processing, particularly in MRI to understand the need for the CS in MRI, and thereby how it could revolutionize the soft tissue imaging to benefit healthcare technology without making major changes in the existing scanner hardware. It would be particularly useful for researchers who have just entered into the exciting field of CS-MRI and would like to quickly go through the developments to date without diving into the detailed mathematical analysis. Finally, it also discusses recent trends and future research directions for implementation of CS-MRI in clinical practice, particularly in Bio- and Neuro-informatics applications.
Download or read book Dynamic Parallel Imaging for Fast MRI and Optimization of CEST Methods for Metabolic MRI written by Felix Glang and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic Resonance Imaging (MRI) is a fascinating example of how basic research in physics, studying nuclear spin and magnetism, has evolved into a highly successful technology that enables non-invasive medical imaging. As such, it provides insight into both anatomy and physiology, and aids in the diagnosis of a wide range of pathologies. In addition, functional MRI is a central tool for addressing neuroscientific questions that seek, for example, a better understanding of the human brain. The basic principle of Magnetic Resonance (MR) technology is that nuclear spins can be manipulated and probed by electromagnetic fields. When done properly, the interactions between the spins, as well as with their microscopic electronic environment and the external electromagnetic fields, allow a large variety of different tissue properties to be accessed and imaged without the use of harmful ionizing radiation. This makes MRI an inherently multimodal imaging technique, yielding information about, for example, proton density, relaxation times, diffusion and perfusion, blood oxygenation, molecular structure, temperature, magnetic susceptibility, electrical and even mechanical properties. Despite the versatility and advantages of this technology, probably the most striking limitation of MRI lies in the comparatively long acquisition times required to obtain the necessary information, especially to achieve sufficient Signal to Noise Ratio (SNR). To address this problem, the aforementioned manipulation and probing of nuclear magnetization has been subject to extensive research and engineering efforts. In particular, approaches to optimize and speed up MRI can be broadly classified into three categories: 1) faster imaging sequences such as Fast Low Angle Shot (FLASH) or Echo Planar Imaging (EPI), 2) hardware-based improvements such as better gradient coils and so-called Parallel Imaging (PI), and 3) reconstruction methods based on tailored signal processing. This thesis covers two distinct topics in the context of optimizing MRI acquisition and reconstruction. As the first topic, a novel concept for improving PI at Ultra-high Field (UHF) MRI is presented. Among all technical developments to speed up MRI acquisition, PI is one of the most successful and widely applied techniques. It relies on the additional localization information provided by the spatial sensitivity profiles of multiple Radio Frequency (RF) receive coils used to detect nuclear magnetization. However, the maximum achievable PI acceleration factor that still provides acceptable image quality is fundamentally limited by the number and spatial independence of the coil sensitivity profiles. The proposed novel concept to improve PI is based on electronically modulated time-varying receive sensitivities enabled by custom-built reconfigurable RF coils. It is investigated and demonstrated how these can be realized experimentally and used advantageously in acquisition and reconstruction. This work thus can be seen as falling into categories 2 and 3 above. As a second topic, Chemical Exchange Saturation Transfer (CEST) is considered as one of the MRI contrast mechanisms listed above that promises to provide insights into the molecular microenvironment and to detect low concentration metabolites. Due to the required sequence structure of repeated RF-prepared readouts, CEST MRI suffers from long scan times. In addition, the extraction of the desired contrast information usually requires computationally complex processing steps. In this context, a data-driven linear projection method for CEST parameter estimation from the acquired raw data is proposed, which allows simple and fast contrast generation and a potential reduction of acquisition times by providing insight into which parts of the CEST data contain relevant information and which parts could be omitted. This project can be seen as belonging to categories 1 and 3 of the MRI optimization methods mentioned above. Finally, a novel and experimental method of optimizing MRI contrast generation is proposed, where both acquisition and contrast mapping are treated as a joint numerical optimization problem. Departing from the conventional way of basing such optimizations on theoretical models and numerical simulations, a model-free framework is implemented here that optimizes both acquisition parameters and contrast extraction schemes purely based on automated exploratory acquisitions running on a real MRI scanner. The method can also be seen as belonging to categories 1 and 3. A proof-of-principle demonstration of this framework is given in the context of CEST MRI. The approach may be particularly useful in situations where a theoretical description of the targeted problem is not available, such as hardware system imperfections. This in turn suggests a possible link to category 2 of the MRI optimization methods mentioned above. Overall, all of these projects highlight the potential that lies in synergistically considering all aspects of MRI related to hardware, acquisition, and reconstruction in order to strive for optimization of acquisition times and information retrieval.
Download or read book Handbook of MRI Technique written by Catherine Westbrook and published by John Wiley & Sons. This book was released on 2022-01-10 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: HANDBOOK OF MRI TECHNIQUE FIFTH EDITION Distinguished educator Catherine Westbrook delivers a comprehensive and intuitive resource for radiologic technologists in this newly revised Fifth Edition of the Handbook of MRI Technique. With a heavy emphasis on protocol optimisation and patient care, the book guides the uninitiated through scanning techniques and assists more experienced technologists with image quality improvement. The new edition includes up-to-date scanning techniques and an additional chapter on paediatric imaging. The latest regulations on MRI safety are referenced and there are expanded sections on slice prescription criteria. The book also includes the contributions of several clinical experts, walking readers through key theoretical concepts, discussing practical tips on cardiac gating, equipment use, patient care, MRI safety, and contrast media. Step-by-step instruction is provided on scanning each anatomical area, complete with patient positioning and image quality optimisation techniques. The book includes: A thorough introduction to the concepts of parameters and trade-offs, as well as pulse sequences, flow phenomena, and artefacts Comprehensive explorations of cardiac gating and respiratory compensation techniques, patient care and safety, contrast agents, and slice prescription criteria Practical discussions of a wide variety of examination areas, including the head and neck, spine, chest, abdomen, pelvis, the upper and lower limbs, and paediatric imaging A companion website with self-assessment questions and image flashcards Perfect for radiography students and newly qualified practitioners, as well as practitioners preparing for MRI-based certification and examination, the Handbook of MRI Technique will also prove to be an invaluable addition to the libraries of students in biomedical engineering technology and radiology residents.
Download or read book MRI Shaping Using Inverse Scattering and Optimization written by Shue-Er Chen and published by . This book was released on 1995 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book MRI for Technologists Second Edition written by Peggy Woodward and published by McGraw-Hill Medical. This book was released on 2001 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: “…a welcome change from the many highly technical MRI texts on the market. It provides a solid foundation of MR technology and serves well as a study guide or reference text to use in practice.” RADIOLOGIC TECHNOLOGY review of prior edition For optimal knowledge of MR imaging, look no further than this user-friendly guide. Highly-experienced technologists clearly explain everything you need to know -- from the underlying science of magnetic resonance imaging, to image evaluation, interaction with patients, and even facility management. *Logical, pedagogical organization maximizes comprehension *Crystal clear illustrations demystify even the most technical subjects *Helpful tables quickly organize protocols and parameters Here are just some of the topics covered: *Basic physics *Commonly-used pulse sequences and parameters *Image interpretation *Protocol development strategies *Safety considerations *contrast media New to this edition: *Advanced MR pulse sequences *Updates on coil technology *Angiographic imaging developments *Improvements in contrast media studies *Breast MRI advances Also of interest: Markisz/Aquilia: Technical Magnetic Resonance Imaging Neseth/Williams: Procedures and Documentation for CT and MRI Woodward/Orrison: MRI Optimization: A Hands On Approach
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 MRI Handbook written by Muhammed Elmaoğlu and published by Springer Science & Business Media. This book was released on 2011-11-17 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: MRI Handbook presents a concise review of the physical principles underlying magnetic resonance imaging (MRI), explaining MR physics, patient positioning, and protocols in an easy-to-read format. The first five chapters of the book introduce the reader to the basics of MR imaging, including the relaxation concept, MR pulse sequences, and MR imaging parameters and options. The second part of the book (chapters 6-11) uses extensive illustrations, images, and protocol tables to explain tips and tricks to achieve optimal MR image quality while ensuring patient safety. Individual chapters are devoted to each major anatomic region, including the central nervous, musculoskeletal, and cardiovascular systems. By using annotated MR images and examples of patient positions used during scanning correlated with sample protocols and parameters, MRI Handbook is a practical resource for imaging professionals to use in the course of their daily practice as well as for students to learn the basic concepts of MR imaging.
Download or read book MRI Physics written by Stephen J. Powers and published by John Wiley & Sons. This book was released on 2021-03-12 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: MRI PHYSICS MRI PHYSICS TECH TO TECH EXPLANATIONS Technologists must have a solid understanding of the physics behind Magnetic Resonance Imaging (MRI), including safety, the hows and whys of the quantum physics of the MR phenomenon, and how to competently operate MRI scanners. Generating the highest quality images of the human body involves thorough knowledge of scanner hardware, pulse sequences, image contrast, geometric parameters, and tissue suppression techniques. MRI Physics: Tech to Tech Explanations is designed to help student MRI technologists and radiotherapists preparing for Advanced MRI certification examinations to better understand difficult concepts and topics in a quick and easy manner. Written by a highly experienced technologist, this useful guide provides clear and reader-friendly coverage of what every MR Technologist needs to know. Topics include safety considerations associated with the magnetic field and RF, pulse sequences, artifacts, MRI math, the much-feared gradients, and I.V. contrast. Provides basic guidance on safety considerations, protocols options, critical thinking, and image contrast optimization Simplifies the challenging topic of MRI physics using straightforward language and clear explanations Covers content for American Registry of Radiologic Technologists (ARRT) and Continuing Qualifications Requirements (CQR) exams Features numerous illustrations and photographs of various MRI concepts, pulse sequence design, artifacts, and the application of concepts in clinical settings MRI Physics: Tech to Tech Explanations is a must-have resource for the experienced and training MRI technologist, medical students, and radiology residency rotations.
Download or read book Compressed Sensing for Magnetic Resonance Image Reconstruction written by Angshul Majumdar and published by Cambridge University Press. This book was released on 2015-02-26 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Expecting the reader to have some basic training in liner algebra and optimization, the book begins with a general discussion on CS techniques and algorithms. It moves on to discussing single channel static MRI, the most common modality in clinical studies. It then takes up multi-channel MRI and the interesting challenges consequently thrown up in signal reconstruction. Off-line and on-line techniques in dynamic MRI reconstruction are visited. Towards the end the book broadens the subject by discussing how CS is being applied to other areas of biomedical signal processing like X-ray, CT and EEG acquisition. The emphasis throughout is on qualitative understanding of the subject rather than on quantitative aspects of mathematical forms. The book is intended for MRI engineers interested in the brass tacks of image formation; medical physicists interested in advanced techniques in image reconstruction; and mathematicians or signal processing engineers.
Download or read book Magnetic Resonance Image Reconstruction written by Mehmet Akcakaya and published by Academic Press. This book was released on 2022-11-04 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic Resonance Image Reconstruction: Theory, Methods and Applications presents the fundamental concepts of MR image reconstruction, including its formulation as an inverse problem, as well as the most common models and optimization methods for reconstructing MR images. The book discusses approaches for specific applications such as non-Cartesian imaging, under sampled reconstruction, motion correction, dynamic imaging and quantitative MRI. This unique resource is suitable for physicists, engineers, technologists and clinicians with an interest in medical image reconstruction and MRI. Explains the underlying principles of MRI reconstruction, along with the latest research“/li> Gives example codes for some of the methods presented Includes updates on the latest developments, including compressed sensing, tensor-based reconstruction and machine learning based reconstruction
Download or read book Learning based Optimization of the Under sampling Pattern in MRI written by Cagla Deniz Bahadir and published by . This book was released on 2019 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: The long scan times of Magnetic Resonance Imaging (MRI) create a bottleneck in patient care and acquisitions can be accelerated by under-sampling in k-space (i.e., the Fourier domain). In this thesis, we focus on the optimization of the sub-sampling pattern with a data-driven framework. Since the reconstruction quality of the models are shown to be strongly dependent on the sub-sampling pattern, we combine the two problems. For a provided sparsity constraint, our method optimizes the sub-sampling pattern and reconstruction model, using an end-to-end unsupervised learning strategy. Our algorithm is trained on full-resolution data that are under-sampled retrospectively, yielding a sub-sampling pattern and reconstruction model that are customized to the type of images represented in the data set. The proposed method, which we call LOUPE (Learning-based Optimization of the Under-sampling PattErn), was implemented by modifying a U-Net, a widely-used convolutional neural network architecture, that we append with the forward model that encodes the under-sampling process. Our experiments with T1- weighted structural brain MRI scans, PD and PDFS weighted knee MRI scans show that the optimized sub-sampling pattern can yield significantly more accurate reconstructions compared to standard random uniform, variable density or cartesian under-sampling schemes. The code is made available at: https: //github.com/cagladbahadir/LOUPE.
