Download or read book Motion Correction and Reduction Techniques in Magnetic Resonance Imaging written by Hope Waggener Korin and published by . This book was released on 1991 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Motion Correction Techniques for Magnetic Resonance Imaging written by Edward Brian Welch and published by . This book was released on 2003 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Motion Correction in MR written by Andre van der Kouwe and published by Academic Press. This book was released on 2022-10-28 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt: Motion Correction in MR: Correction of Position, Motion, and Dynamic Changes, Volume Eight provides a comprehensive survey of the state-of-the-art in motion detection and correction in magnetic resonance imaging and magnetic resonance spectroscopy. The book describes the problem of correctly and consistently identifying and positioning the organ of interest and tracking it throughout the scan. The basic principles of how image artefacts arise because of position changes during scanning are described, along with retrospective and prospective techniques for eliminating these artefacts, including classical approaches and methods using machine learning. Internal navigator-based approaches as well as external systems for estimating motion are also presented, along with practical applications in each organ system and each MR modality covered. This book provides a technical basis for physicists and engineers to develop motion correction methods, giving guidance to technologists and radiologists for incorporating these methods in patient examinations. Provides approaches for correcting scans prospectively and retrospectively Shows how motion and secondary effects such as field changes manifest in MR scans as artifacts and subtle biases in quantitative research Gives methods for measuring motion and associated field changes, quantifying motion and judging the accuracy of the motion and field estimates
Download or read book Motion Artifact Reduction in Steady state Magnetic Resonance Imaging written by Richard Reeve Ingle and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic resonance imaging (MRI) is a powerful medical imaging modality that offers excellent soft-tissue contrast and numerous contrast-generation mechanisms. However, due to the relatively low signal-to-noise ratio (SNR) of MRI, many volumetric and high-resolution imaging techniques require long acquisition times yielding an increased sensitivity to motion. In many cardiac MRI applications, one of the most significant challenges is the reduction of motion artifacts caused by cardiac and respiratory motion. In these applications, a combination of SNR-efficient balanced steady-state free precession (bSSFP) pulse sequences, high-temporal-resolution motion tracking acquisitions, and retrospective motion correction algorithms are commonly employed to mitigate motion artifacts. Despite recent advances in steady-state pulse sequence development, navigator motion tracking acquisitions, and motion correction algorithms, motion artifact reduction continues to be a significant challenge for many cardiac MRI applications. A novel class of perturbed steady-state free precession (SSFP) pulse sequences is developed and analyzed, yielding new forms of steady-state image contrast. These sequences utilize alternating perturbations of sequence parameters such as the repetition time (TR) and flip angle to produce oscillating steady-state frequency responses. Large oscillations of the signal magnitude and phase occur at specific off-resonant frequencies, and the combination of these signals can yield spectrally selective image contrast. Applications are demonstrated for retrospective motion correction using cardiac fat navigator acquisitions in free-breathing whole-heart cardiac MRI and for positive-contrast imaging of superparamagnetic iron-oxide nanoparticles. The bSSFP pulse sequence is widely used in cardiac imaging due to its high signal per unit time and excellent blood-myocardial contrast. A drawback of this pulse sequence is the generation of bright signal from fat, which can lead to unwanted image artifacts. Alternating repetition time (ATR) SSFP is a recently developed sequence that generates fat-suppressed steady-state contrast, but it requires the addition of an unused time interval every repetition, making it less time efficient than bSSFP. A small modification to the ATR pulse sequence is proposed to enable the acquisition of a one-dimensional self-gating signal during this unused time interval. The self-gating signals are used for retrospective cardiac triggering in breath-held cardiac cine imaging, and the proposed sequence is evaluated in volunteer and patient populations. The resulting ECG-free self-gated images have no statistically significant differences compared with conventional ECG-gated images. The proposed sequence also yields robust suppression of epicardial fat compared with standard bSSFP cardiac cine imaging. In coronary MR angiography (CMRA), high-resolution, whole-heart acquisitions are typically required for visualization of the relatively small coronary vasculature. These acquisitions require long scan times that are carried out during free breathing, which can lead to severe ghosting and blurring artifacts without motion compensation. A nonrigid retrospective motion correction technique is proposed for motion artifact reduction in image-navigated CMRA. The technique reconstructs a bank of motion-compensated CMRA images using many candidate motion estimates derived from navigator images acquired throughout the scan. A metric-based autofocusing approach is used to automatically generate a final nonrigid-motion-corrected image from this bank of images. The proposed technique is evaluated in volunteer and patient studies, leading to improvements in vessel sharpness and image quality compared with rigid-body translational motion correction. These new steady-state pulse sequences, motion tracking acquisitions, and nonrigid reconstruction techniques address several of the challenges to cardiac MRI, enabling the reduction of motion artifacts and improvement of image quality.
Download or read book Advanced Motion Corrected Reconstruction Techniques for Magnetic Resonance Imaging written by Gastão Cruz and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proposed method reduced scan times by 2.6x when compared with the gated acquisition while maintaining similar image quality. In the second application, the framework is combined with interleaved image navigators to add high temporal resolution motion correction. This method also presented similar coronary lumen quality to the gated, despite a 1.6x reduction in scan time. Additionally, it presented sig- nificantly superior vessel wall quality when compared to translation correction. In the third application, the framework is combined with Parallel Imaging, Compressed Sensing and interleaved image naviga- tors. Initial results indicate the proposed approach produces signifi- cantly superior water and fat images than translation correction.
Download or read book Motion Correction Techniques for Three dimensional Magnetic Resonance Imaging Acquired with the Elliptical Centric View Order Or the Shells Trajectory written by Yunhong Shu and published by . This book was released on 2006 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pitfalls in Diagnostic Radiology written by Wilfred C. G. Peh and published by Springer. This book was released on 2014-11-10 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: The practice of diagnostic radiology has become increasingly complex, with the use of numerous imaging modalities and division into many subspecialty areas. It is becoming ever more difficult for subspecialist radiologists, general radiologists, and residents to keep up with the advances that are occurring year on year, and this is particularly true for less familiar topics. Failure to appreciate imaging pitfalls often leads to diagnostic error and misinterpretation, and potential medicolegal problems. This textbook, written by experts from reputable centers across the world, systematically and comprehensively highlights the pitfalls that may occur in diagnostic radiology. Both pitfalls specific to different modalities and techniques and those specific to particular organ systems are described with the help of numerous high-quality illustrations. Recognition of these pitfalls is crucial in helping the practicing radiologist to achieve a more accurate diagnosis.
Download or read book Introduction to Functional Magnetic Resonance Imaging written by Richard B. Buxton and published by Cambridge University Press. This book was released on 2009-08-27 with total page 479 pages. Available in PDF, EPUB and Kindle. Book excerpt: Functional Magnetic Resonance Imaging (fMRI) has become a standard tool for mapping the working brain's activation patterns, both in health and in disease. It is an interdisciplinary field and crosses the borders of neuroscience, psychology, psychiatry, radiology, mathematics, physics and engineering. Developments in techniques, procedures and our understanding of this field are expanding rapidly. In this second edition of Introduction to Functional Magnetic Resonance Imaging, Richard Buxton – a leading authority on fMRI – provides an invaluable guide to how fMRI works, from introducing the basic ideas and principles to the underlying physics and physiology. He covers the relationship between fMRI and other imaging techniques and includes a guide to the statistical analysis of fMRI data. This book will be useful both to the experienced radiographer, and the clinician or researcher with no previous knowledge of the technology.
Download or read book Scan Acceleration and Motion Correction for Cardiovascular Magnetic Resonance Imaging written by Jieying Luo and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic resonance imaging (MRI) is a powerful medical imaging modality providing excellent soft-tissue contrast without exposing the patient to ionizing radiation. In particular, MRI plays a critical role in the diagnosis and management of cardiovascular disease with the possibility of obtaining a wide range of anatomical and functional information in a single examination. However, despite technical advancements such as parallel imaging and compressed sensing, the scan time of cardiovascular MRI is still relatively long compared to X-ray or CT. The temporal resolution for functional assessment is limited, and compensation for respiratory and cardiac motion remains challenging. To improve the temporal resolution, an undersampling acquisition scheme and a low-rank matrix-completion reconstruction method recovering the missing data are developed and applied to perfusion imaging in the lower extremities. To exploit the spatial-temporal information redundancy, the proposed method formulates the image construction as an optimization problem with the low-rank constraint and the data-consistency constraint. With the proposed method, dynamic contrast-enhanced perfusion imaging in the lower extremities with high temporal resolution (3 s) and volumetric coverage ( 32x16x32 cm3) is achieved. Pulse sequence design is another approach to achieve scan acceleration. Recognizing that the region of interest (ROI) is smaller than the full spatial extent of the anatomy in coronary magnetic resonance angiography (MRA), a new magnetization preparation sequence that combines outer volume suppression with T2 preparation is designed and implemented, enabling accelerated free-breathing whole-heart coronary MRA with enhanced blood-myocardium contrast in a scan time of less than 3 minutes by reducing the image field-of-view. Two nonrigid motion-correction methods are also developed to reduce the motion artifacts generated during the scan. These two methods extract several motion trajectories from 3D image-based navigators (iNAVs) and compensate for them with an autofocusing algorithm. A bank of motion-corrected images is generated by motion correction with every motion trajectory, and the final image is assembled on a pixel-by-pixel basis with the best-focused pixel chosen from the bank of images according to a localized gradient entropy metric. The first method is developed for free-breathing whole-heart coronary MRA in which the motion is complicated and nonrigid. Both global rigid motion and localized nonrigid motion are extracted from the 3D iNAVs. The second method is designed for abdominal MRA, in which the imaging volume is divided into ROIs with different 3D translational motion patterns. An automatic ROI-clustering method is developed and a translational motion trajectory is estimated for every ROI. Both motion correction methods demonstrate improved vessel sharpness in the in vivo studies. The image reconstruction method, pulse sequence and motion-correction methods developed enable scan acceleration and motion correction to address several challenges in cardiovascular MRI. These methods show promise of extending the diagnostic utility of MRI in this application.
Download or read book Acquisition and Processing Techniques for Image Based Prospective Motion Correction in Magnetic Resonance Imaging written by Daniel Christopher Hoinkiss and published by . This book was released on 2018 with total page 0 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 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 Advanced Motion Corrected Reconstruction Techniques for Magnetic Resonance Imaging written by Gastao Jose Lima Da Cruz and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetic Resonance Imaging Gradient Modulation Technique for Motion Artifact Reduction and Flow Quantification written by Jeffrey Lewis Duerk and published by . This book was released on 1987 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Motion Correction Techniques for in Vivo Magnetic Resonance Spectroscopy of the Human Spinal Cord written by Andreas Hock and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Signal Processing for Magnetic Resonance Imaging and Spectroscopy written by Hong Yan and published by CRC Press. This book was released on 2002-02-20 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reference/text contains the latest signal processing techniques in magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) for more efficient clinical diagnoses-providing ready-to-use algorithms for image segmentation and analysis, reconstruction and visualization, and removal of distortions and artifacts for increased detec
Download or read book Magnetic Resonance Imaging written by Robert W. Brown and published by John Wiley & Sons. This book was released on 2014-06-23 with total page 976 pages. Available in PDF, EPUB and Kindle. Book excerpt: New edition explores contemporary MRI principles and practices Thoroughly revised, updated and expanded, the second edition of Magnetic Resonance Imaging: Physical Principles and Sequence Design remains the preeminent text in its field. Using consistent nomenclature and mathematical notations throughout all the chapters, this new edition carefully explains the physical principles of magnetic resonance imaging design and implementation. In addition, detailed figures and MR images enable readers to better grasp core concepts, methods, and applications. Magnetic Resonance Imaging, Second Edition begins with an introduction to fundamental principles, with coverage of magnetization, relaxation, quantum mechanics, signal detection and acquisition, Fourier imaging, image reconstruction, contrast, signal, and noise. The second part of the text explores MRI methods and applications, including fast imaging, water-fat separation, steady state gradient echo imaging, echo planar imaging, diffusion-weighted imaging, and induced magnetism. Lastly, the text discusses important hardware issues and parallel imaging. Readers familiar with the first edition will find much new material, including: New chapter dedicated to parallel imaging New sections examining off-resonance excitation principles, contrast optimization in fast steady-state incoherent imaging, and efficient lower-dimension analogues for discrete Fourier transforms in echo planar imaging applications Enhanced sections pertaining to Fourier transforms, filter effects on image resolution, and Bloch equation solutions when both rf pulse and slice select gradient fields are present Valuable improvements throughout with respect to equations, formulas, and text New and updated problems to test further the readers' grasp of core concepts Three appendices at the end of the text offer review material for basic electromagnetism and statistics as well as a list of acquisition parameters for the images in the book. Acclaimed by both students and instructors, the second edition of Magnetic Resonance Imaging offers the most comprehensive and approachable introduction to the physics and the applications of magnetic resonance imaging.
