Download or read book Quantitative Image Quality Evaluation of Fast Magnetic Resonance Imaging written by Donglai Huo and published by . This book was released on 2007 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fast Quantitative Magnetic Resonance Imaging written by Guido Buonincontri and published by Morgan & Claypool Publishers. This book was released on 2020-02-20 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: Among medical imaging modalities, magnetic resonance imaging (MRI) stands out for its excellent soft-tissue contrast, anatomical detail, and high sensitivity for disease detection. However, as proven by the continuous and vast effort to develop new MRI techniques, limitations and open challenges remain. The primary source of contrast in MRI images are the various relaxation parameters associated with the nuclear magnetic resonance (NMR) phenomena upon which MRI is based. Although it is possible to quantify these relaxation parameters (qMRI) they are rarely used in the clinic, and radiological interpretation of images is primarily based upon images that are relaxation time weighted. The clinical adoption of qMRI is mainly limited by the long acquisition times required to quantify each relaxation parameter as well as questions around their accuracy and reliability. More specifically, the main limitations of qMRI methods have been the difficulty in dealing with the high inter-parameter correlations and a high sensitivity to MRI system imperfections. Recently, new methods for rapid qMRI have been proposed. The multi-parametric models at the heart of these techniques have the main advantage of accounting for the correlations between the parameters of interest as well as system imperfections. This holistic view on the MR signal makes it possible to regress many individual parameters at once, potentially with a higher accuracy. Novel, accurate techniques promise a fast estimation of relevant MRI quantities, including but not limited to longitudinal (T1) and transverse (T2) relaxation times. Among these emerging methods, MR Fingerprinting (MRF), synthetic MR (syMRI or MAGIC), and T1‒T2 Shuffling are making their way into the clinical world at a very fast pace. However, the main underlying assumptions and algorithms used are sometimes different from those found in the conventional MRI literature, and can be elusive at times. In this book, we take the opportunity to study and describe the main assumptions, theoretical background, and methods that are the basis of these emerging techniques. Quantitative transient state imaging provides an incredible, transformative opportunity for MRI. There is huge potential to further extend the physics, in conjunction with the underlying physiology, toward a better theoretical description of the underlying models, their application, and evaluation to improve the assessment of disease and treatment efficacy.

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 Advanced Image Processing in Magnetic Resonance Imaging written by Luigi Landini and published by CRC Press. This book was released on 2018-10-03 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: The popularity of magnetic resonance (MR) imaging in medicine is no mystery: it is non-invasive, it produces high quality structural and functional image data, and it is very versatile and flexible. Research into MR technology is advancing at a blistering pace, and modern engineers must keep up with the latest developments. This is only possible with a firm grounding in the basic principles of MR, and Advanced Image Processing in Magnetic Resonance Imaging solidly integrates this foundational knowledge with the latest advances in the field. Beginning with the basics of signal and image generation and reconstruction, the book covers in detail the signal processing techniques and algorithms, filtering techniques for MR images, quantitative analysis including image registration and integration of EEG and MEG techniques with MR, and MR spectroscopy techniques. The final section of the book explores functional MRI (fMRI) in detail, discussing fundamentals and advanced exploratory data analysis, Bayesian inference, and nonlinear analysis. Many of the results presented in the book are derived from the contributors' own work, imparting highly practical experience through experimental and numerical methods. Contributed by international experts at the forefront of the field, Advanced Image Processing in Magnetic Resonance Imaging is an indispensable guide for anyone interested in further advancing the technology and capabilities of MR imaging.

Download or read book Magnetic Resonance for Food Quality Evaluation written by Seong-Min Kim and published by . This book was released on 1995 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ultrafast MRI written by Jörg F. Debatin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: The imaging potential of the MR experiment continues to evolve. In recent years, an increasing number of fast and ultrafast imaging strategies has been described. In this evolu tion the definition of the terms fast and ultrafast has been blurred. Hence they are frequently used interchangeably. The evolution of these methods has been based on two related, yet separate developments: an increasingly thorough understand ing of the complexities inherent to pulse sequence design and the increasing availability of stronger and faster gradient sys tems. The combination of these two factors has laid the foun dation for vast reductions of MRI data acquisition times. Min utes have been replaced by seconds. Beyond shortening MR examination times and thereby increasing patient throughput, a most significant consequence has been the ability to acquire complex MR image sets within the time confines of a single breath-hold. The constraints placed by the presence of respi ratory motion have thus been effectively eliminated. Ultrafast breath-held data acquisition strategies already represent the backbone of many abdominal, thoracic and even pelvic imaging protocols. The enhanced image quality permits full exploitation of the unsurpassed soft tissue contrast inherent to the MR experiment. Beyond improving the quality of ex isting applications, the implementation of ultrafast imaging techniques has permitted the exploration of new imaging in dications, particularly in the area of perfusion and diffusion as well as ultrafast 3D imaging.

Download or read book Assessment of Image Quality Requirements in Magnetic Resonance Imaging for Quantitative Brain Morphometry written by Pavel Falkovskiy and published by . This book was released on 2016 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mots-clés de l'auteur: magnetic resonance imaging ; structural MRI ; accelerated MPRAGE protocols ; brain morphometry analysis ; reproducibility of brain volume measurements.

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 Magnetic Resonance Imaging written by Robert Sigal and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic Resonance Imaging (MRI) is a rapidly evolving technique which is having a significant impact on medical imaging. Only a few years ago, al though Nuclear Magnetic Resonance (NMR) was well known as an important analytical technique in the field of chemical analysis, it was effectively un known in medical circles. Following the initial work of PAUL LAUTERBUR and RAYMOND DAMADIAN in the early 1970s demonstrating that it was possible to use NMR to produce im ages, progress in the medical fields was relatively slow. Recently, however, with the availability of commercial systems, progress has been very rapid, with increasing acceptance of MRI as a basic imaging technique, and the develop ment of exciting new applications. MRI is a relatively complex technique. First, the image depends on many more intrinsic and extrinsic parameters than it does of in techniques like X-ra diography and computed tomography, and secondly, the intrinsic parameters such as T1 and T2 are conceptually complex, involving ideas not usually de scribed in traditional medical imaging courses. In order to produce good MR images efficiently, and to obtain the maximum information from them, it is necessary to appreciate, if not to fully understand, these parameters. Further more, knowledge of how the image is produced helps in appreciating the ori gin of the artifacts sometimes found in MRI due to effects like patient motion and fluid flow.

Download or read book MRI of Short and Ultrashort T 2 Tissues written by Jiang Du and published by Springer Nature. This book was released on 2023 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zusammenfassung: This book comprehensively covers ultrashort echo time (UTE), zero echo time (ZTE), and other magnetic resonance imaging (MRI) acquisition techniques for imaging of short and ultrashort-T2 tissues. MRI uses a large magnet and radio waves to generate images of tissues in the body. The MRI signal is characterized by two time constants, spin-lattice relaxation time (T1) which describes how fast the longitudinal magnetization recovers to its initial value after tipping to the transverse plane, and spin-spin relaxation time (T2) which describes how fast the transverse magnetization decays. Conventional MRI techniques have been developed to image and quantify tissues with relatively long T2s. However, the body also contains many tissues and tissue components such as cortical bone, menisci, ligaments, tendons, the osteochondral junction, calcified tissues, lung parenchyma, iron containing tissues, and myelin, which have short or ultrashort-T2s. These tissues are "invisible" with conventional MRI, and their MR and tissue properties are not measurable. UTE and ZTE type sequences resolve these challenges and make these tissues visible and quantifiable. This book first introduces the basic physics of conventional MRI as well as UTE and ZTE type MRI, including radiofrequency excitation, data acquisition, and image reconstruction. A series of contrast mechanisms are then introduced and these provide high resolution, high contrast imaging of short and ultrashort-T2 tissues. A series of quantitative UTE imaging techniques are described for measurement of MR tissue properties (proton density, T1, T2, T2*, T1p,magnetization transfer, susceptibility, perfusion and diffusion). Finally, clinical applications in the musculoskeletal, neurological, pulmonary and cardiovascular systems are described. This is an ideal guide for physicists and radiologists interested in learning more about the use of UTE and ZTE type techniques for MRI of short and ultrashort-T2 tissues

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 Development of Deep Learning Methods for Magnetic Resonance Imaging Reconstruction and Analysis written by Yuhua Chen and published by . This book was released on 2021 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic resonance image (MRI) is a widely used non-invasive radiation-free imaging technique that uniquely provides structural and functional information for disease detection, diagnosis, and treatment planning. However, the conventional MRI imaging techniques are typically slow and low in spatial or time resolution, resulting in long scan times and more susceptibility to motion artifacts. Moreover, a fast MRI scan usually comes in a low spatial resolution, making it less desirable for clinical application. A recently proposed technique, Multi-tasking MRI (MTMRI), significantly improves the scan efficiency with high temporal resolution. Nevertheless, the iterative reconstruction requires a lot of computational resources and takes a long time to process, making it challenging to fit in the clinical routine. Additionally, when doing image post-processing with MRI, despite MRI providing a good contrast of soft tissues, the variety in weighted contrast MRI's intensity values makes it challenging to extract image features compared with other quantitative imaging techniques. The most significant contribution of this dissertation's work is to address the three limitations above by developing a unified multi-purpose structure with deep-learning (DL) techniques. We achieved three primary goals in three different areas: 1) A general framework for highly accelerated MRI scanning without sacrificing spatial resolution, 2) reduce reconstruction time for motion-resolved free-breathing MRI technique, 3) accurately fully automated segmentation for abdominal MRI for fast image post-processing. All technical improvements utilize DL techniques to improve MRI in different aspects: to improve image quality in fast MRI scans, reduce reconstruction time in motion-resolved MRI, and reduce tedious human labors in abdominal MRI. First, a DL-based Super-Resolution (SR) technique is developed and evaluated in both brain MRI and coronary MR Angiography (MRA). SR can recover the image quality and structural details from a 4x and 16x low-resolution fast MRI scan. For brain MRI, several SR networks have been developed. The proposed network (mDCSRN) has successfully recovered the brain structural details from a 4x low-resolution fast scan. It is developed and evaluated on an open access high-resolution T1w brain MRI with 1131 healthy volunteers. Quantitative results show that it can achieve 4x acceleration in scan while keeping similar image quality. For coronary MRA, introducing a domain adaptive network (DRAGAN) jointly trained on both coronary and brain MRA to overcome catastrophic failures commonly in training a GAN in a small dataset, we successfully accelerated the MRA acquisition by a factor of 16. Second, DL networks are developed to accelerate the reconstruction of a 5-dimensional (5D) Multitasking MRI (MTMRI). The MTMRI is a respiratory and cardiac-motion-resolved, high-temporal-resolution technique that provides quantitative T1 mapping. However, the massive size of many dynamic MRI problems prevents deep learning networks from directly exploiting global temporal relationships. By applying deep neural networks inside a priori calculated temporal feature spaces, we enable deep learning reconstruction with global temporal modeling even for image sequences with >40,000 frames. One proposed variation of our approach using dilated multi-level Densely Connected Network (mDCN) speeds up feature space coordinate calculation by 3000x compared to conventional iterative methods, from 20 minutes to 0.39 seconds. Thus, the combination of low-rank tensor and deep learning models makes large-scale dynamic MRI feasible and practical for routine clinical application. Third, we developed Automated deep Learning-based Abdominal Multi-Organ segmentation (ALAMO) technique based on 2D U-net and a densely connected network structure with tailored design in data augmentation and training procedures. The model takes in multi-slice MR images and generates the output of segmentation results. 3.0-Tesla T1 VIBE (Volumetric Interpolated Breath-hold Examination) images of 102 subjects were used in our study. Ten OARs were studied, including the liver, spleen, pancreas, left/right kidneys, stomach, duodenum, small intestine, spinal cord, and vertebral bodies. ALAMO generated segmentation labels in good agreement with the manual results. Specifically, among the 10 OARs, 9 achieved high Dice Similarity Coefficients (DSCs) in the range of 0.87-0.96, except for the duodenum with a DSC of 0.80. Overall, the ALAMO model matched the state-of-the-art techniques in performance.

Download or read book Modern Imaging Evaluation of the Brain Body and Spine An Issue of Magnetic Resonance Imaging Clinics written by Lara A. Brandao and published by Elsevier Health Sciences. This book was released on 2013-05-28 with total page 549 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic Resonance Spectroscopy (MRS) is an analytical method used in chemistry that enables the identification and quantification of metabolites in samples. It differs from conventional Magnetic Resonance Imaging in that spectra provide physiological and chemical information instead of anatomy. This issue examines MRS methods for a wide variety of body imaging needs.

Download or read book Quantitative Assessment of Magnetic Resonance Imaging Systems written by Donald William McRobbie and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quality Control and Artefacts in Magnetic Resonance Imaging written by Donald McRobbie and published by Institute of Physics and Engineering in Medicine. This book was released on 2017-01-31 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Quality Control and Artefacts in Magnetic Resonance Imaging is an authoritative, comprehensive and practical guide for all medical imaging professionals with an interest in evaluating and assuring image quality and scanner performance in MRI. Written by leading UK experts, the report is a major revision of IPEM Report 80: Quality Control in Magnetic Resonance Imaging. The report is in two parts. Part I deals with quality control, with chapters on test object design and test materials, signal parameter measurement (signal-to-noise ratio, ghosting, etc.), geometric parameters (resolution, distortion), slice parameters (position, width and profile), relaxometry and contrast. For each parameter a consistent and systematic structure provides a literature review with reference to current international standards, parameter definition, description of test methods, practical guidance including frequency of measurement, analysis and interpretation of results, and pitfalls. A specialist QC chapter is a new and unique feature providing guidance relating to specific clinical and research techniques: field mapping, diffusion, BOLD fMRI, voxel-based morphometry, dynamic contrast-enhanced MRI, quantitative velocity mapping, spectroscopy, and ultra-high field MRI. Part II provides a comprehensive and exhaustive encyclopaedia of MRI artefacts both common and rare arising from technical limitations and faults, patient and organ motion, tissue properties, intrinsic MR physics, and reconstruction limitations. Pictorial examples of each artefact from clinical or phantom images are provided along with a detailed explanation of the causes and advice on reducing, avoiding or removing the artefact. A summary table of artefact appearance, causes and remediation will enable readers to diagnose and solve their own artefact problems. The practical nature of the report is underpinned by academic rigour with 269 references and a comprehensive index. Quality Control and Artefacts in Magnetic Resonance is an essential reference for all MRI departments and MRI professionals.

Download or read book Quantitative MRI in Cancer written by Thomas E. Yankeelov and published by Taylor & Francis. This book was released on 2011-09-13 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: Propelling quantitative MRI techniques from bench to bedside, Quantitative MRI in Cancer presents a range of quantitative MRI methods for assessing tumor biology. It includes biophysical and theoretical explanations of the most relevant MRI techniques as well as examples of these techniques in cancer applications.The introductory part of the book c

Download or read book Quantitative MRI of the Brain written by Mara Cercignani and published by CRC Press. This book was released on 2018-01-12 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt: Building on the success of the first edition of this book, the winner of the 2004 British Medical Association Radiology Medical Book Competition, Quantitative MRI of the Brain: Principles of Physical Measurement gives a unique view on how to use an MRI machine in a new way. Used as a scientific instrument it can make measurements of a myriad of physical and biological quantities in the human brain and body. For each small tissue voxel, non-invasive information monitors how tissue changes with disease and responds to treatment. The book opens with a detailed exposition of the principles of good practice in quantification, including fundamental concepts, quality assurance, MR data collection and analysis and improved study statistical power through minimised instrumental variation. There follow chapters on 14 specific groups of quantities: proton density, T1, T2, T2*, diffusion, advanced diffusion, magnetisation transfer, CEST, 1H and multi-nuclear spectroscopy, DCE-MRI, quantitative fMRI, arterial spin-labelling and image analysis, and finally a chapter on the future of quantification. The physical principles behind each quantity are stated, followed by its biological significance. Practical techniques for measurement are given, along with pitfalls and examples of clinical applications. This second edition of this indispensable 'how to' manual of quantitative MR shows the MRI physicist and research clinician how to implement these techniques on an MRI scanner to understand more about the biological processes in the patient and physiological changes in healthy controls. Although focussed on the brain, most techniques are applicable to characterising tissue in the whole body. This book is essential reading for anyone who wants to use the gamut of modern quantitative MRI methods to measure the effects of disease, its progression, and its response to treatment. Features: The first edition was awarded the book prize for Radiology by the British Medical Association in 2004 Written by an authority in the field: Professor Tofts has an international reputation for quantification in MRI Gives specific ‘how to’ information for implementation of MRI measurement sequence techniques