Download or read book Artifact Reduction in Functional Magnetic Resonance Imaging written by Brian Wowk and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Artifact Reduction in Functional Magnetic Resonance Imaging written by and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reduction of Artifacts in Functional Magnetic Resonance Imaging written by Louai Al-Dayeh and published by . This book was released on 1999 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Motion Artifact Reduction in Magnetic Resonance Imaging written by Shreyas Vasanawala and published by . This book was released on 2000 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Image Artifact Reduction for Fast Magnetic Resonance Imaging written by Joseph Yitan Cheng and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic resonance imaging (MRI) is a rich source for diagnostic information. It has the ability to obtain excellent soft-tissue contrast at a very high spatial resolution. The imaging process of this modality can be conveniently described as a linear system with Fourier encoding. However, to increase flexibility and robustness, imaging techniques are used that cause basic assumptions of this model to fall apart. As a result, image artifacts arise, decreasing the clinical quality of the scans. More sophisticated methods that take these effects into account must be considered. Many of the errors reside in both the spatial and frequency domain, so simple linear solutions do not suffice. Two sources of image artifacts are investigated: (1) concomitant gradient field and field inhomogeneity and (2) nonrigid motion in free-breathing acquisitions. Each image-artifact source has specific effects which are dependent on the application. For real-time cardiac imaging with spiral k-space trajectories, concomitant gradient field and field inhomogeneity errors result in image blurring. Two fast and practical solutions are developed and applied to real-time cardiac studies and high-resolution cardiac studies. MRI is also a compelling choice for imaging pediatric patients as they are highly susceptible to risks of ionizing radiation of computed tomography and nuclear scintigraphy studies. However, this imaging modality is highly sensitive to motion. The motion can result in destructive image artifacts. To enable free-breathing volumetric exams, novel data acquisition strategies and image reconstruction techniques are developed to compensate for nonrigid respiratory motion. These methods are demonstrated in select pediatric patient studies. Image artifacts fromrespiratory motion are reduced from the free-breathing abdominal scans.
Download or read book Artifact Reduction Techniques in FMRI Spiral Imaging and Spectroscopic Imaging written by Keith Arron Heberlein and published by . This book was released on 2003 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Motion Artifact Reduction in Magnetic Resonance Imaging Through Navigator Processing written by Robert W. Schaffer and published by . This book was released on 2009 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contrast Enhancement and Artifact Reduction in Steady state Magnetic Resonance Imaging written by Neal Kepler Bangerter and published by . This book was released on 2004 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Truncation Artifact Reduction in Magnetic Resonance Imaging written by Robert Todd Constable and published by . This book was released on 1990 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ultra High Field Magnetic Resonance Imaging written by Pierre-Marie Robitaille and published by Springer Science & Business Media. This book was released on 2007-12-31 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt: The foundation for understanding the function and dynamics of biological systems is not only knowledge of their structure, but the new methodologies and applications used to determine that structure. This volume in Biological Magnetic Resonance emphasizes the methods that involve Ultra High Field Magnetic Resonance Imaging. It will interest researchers working in the field of imaging.
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 Spiral Imaging and Motion Artifact Reduction for Dynamic Magnetic Resonance Imaging written by Jan-Ray Liao and published by . This book was released on 1997 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Comparison of Metal Artifact Reduction Techniques in Magnetic Resonance Imaging of Carbon and Titaniuem Spinal Implants written by Laura Constance Graf 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 Introduction to Functional Magnetic Resonance Imaging written by Richard B. Buxton and published by Cambridge University Press. This book was released on 2002-01-07 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: Functional Magnetic Resonance Imaging (fMRI) is now a standard tool for mapping activation patterns in the human brain. This highly interdisciplinary field involves neuroscientists and physicists as well as clinicians who need to understand the rapidly increasing range, flexibility and sophistication of the techniques. In this book, Richard Buxton, a leading authority on fMRI, provides an invaluable introduction for this readership to how fMRI works, from basic principles and the underlying physics and physiology, to newer techniques such as arterial spin labeling and diffusion tensor imaging.
Download or read book Functional MRI written by Scott H. Faro and published by Springer Science & Business Media. This book was released on 2006-11-22 with total page 543 pages. Available in PDF, EPUB and Kindle. Book excerpt: Functional magnetic resonance imaging (fMRI) measures quick, tiny metabolic changes that take place in the brain, providing the most sensitive method currently available for identifying, investigating, and monitoring brain tumors, stroke, and chronic disorders of the nervous system like multiple sclerosis, and brain abnormalities related to dementia or seizures. This overview explores experimental research design, outlines challenges and limitations of fMRI, provides a detailed neuroanatomic atlas, and describes clinical applications of fMRI in cognitive, sensory, motor, and pharmacological cases, translating research into clinical application.
