Download or read book Prospective Multiaxial Motion Correction for Functional Magnetic Resonance Imaging written by Heidi Alissa Ward and published by . This book was released on 2001 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comprehensive Head Motion Correction For Functional Magnetic Resonance Imaging written by Zahra Faraji-Dana and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Head motion artifacts are major confounds that limit use of functional magnetic resonance imaging (fMRI) in neuroscience research and clinical settings. Prospective motion correction is a promising candidate solution for head motion in fMRI that ideally allows the image plane to remain fixed with respect to the moving head (i.e., in the moving reference frame). Prospective motion correction has been shown to correct successfully for rigid body movement artifacts, but residual geometric distortion due to dynamic magnetic field nonuniformities and dynamic changes in receiver coil sensitivity profiles in the moving reference frame still remain a problem. This thesis focuses on three objectives. First, I investigated and corrected for the influence of respiratory effects on the performance of dynamic geometric correction using Phase Labeling for Additional Coordinate Encoding (PLACE). It was demonstrated that PLACE combined with the dynamic off-resonance in k-space (DORK) method, and temporal averaging substantially improved fMRI data quality in comparison to the results obtained by standard processing and static geometric distortion correction. Second, I verified that appreciable signal artifacts occur due to coil sensitivity changes in fMRI maps in presence of overt head motion with prospective motion correction using Prospective Acquisition CorrEction (PACE) technique [1]. Sensitivity map compensations were shown to suppress these artifacts and provide improved fMRI results Third, I studied signal artifacts resulted from the head motion between the coil sensitivity map measurement (i.e., the calibration step) and data acquisition for fMRI with parallel-imaging reconstruction methods using two parallel imaging schemes: sensitivity encoding (SENSE) and generalized autocalibrating partially parallel acquisitions (GRAPPA) with acceleration factors 2 and 4. Coil sensitivity map compensations were shown to improve fMRI results obtained with PACE in the presence of overt head motion compared to those obtained with no overt head motion. Overall, prospective motion correction, integrated dynamic geometric distortion correction, and coil sensitivity map correction present an appealing compound approach for suppressing rigid and non-rigid motion artifacts during fMRI. This thesis has developed robust and comprehensive head motion correction strategies that ultimately will expand the patient populations for which fMRI can be performed robustly.
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 Prospective Motion Correction with Chemically Selective Spherical Navigator Echoes for Functional Magnetic Resonance Imaging written by Narter Ari and published by . This book was released on 2004 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Prospective Correction of Through plane Motion Artifact for FMRI written by Sara Elizabeth Yancey and published by . This book was released on 2008 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Functional magnetic resonance imaging (fMRI) is a technique useful for mapping patterns of neuronal activation in healthy and abnormal human brain. However, fMRI is limited in application by sensitivity to millimetre-scale head motion. Motion through the imaging plane creates "artifact", or unwanted signal change, that mimics neuronal activation and cannot be removed in post-processing. Prospective correction is a motion-correction strategy that employs an imaging plane that adapts in response to motion to prevent artifact, and may be successful where other motion-correction techniques have failed. This thesis details a simulation of through-plane motion artifact that agrees with experimental observations. A practical implementation of 1D prospective correction is also presented, with effective correction of artifact within a phantom undergoing simple and complex through-plane motion. These results suggest that prospective correction may ultimately improve the quality of fMRI for high-motion subjects.
Download or read book Detection and Correction of Patient Motion in Magnetic Resonance Imaging written by Murat Aksoy and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the sequential nature of magnetic resonance imaging (MRI) data acquisition, correction of image artifacts originating from involuntary patient motion is essential for reliable diagnostic quality. Especially during MRI scans of certain patient populations such as children, elderly or patients with certain medical conditions (e.g. stroke, Parkinson's), motion correction methods must be incorporated into the MR imaging protocol for adequate image quality. With increased demands for higher resolution or time-resolved examinations (e.g. functional MRI), examination times also increase and even willing patients might have trouble staying still during the course of the examination. The first part of this thesis provides a method for retrospective correction of head motion artifacts using a multi-shot spiral-in \ & out readout and parallel-imaging based iterative image reconstruction. The spiral-in part provided a low resolution image that was used for measurement of head motion. Due to rotational motion, locally undersampled areas appear in MR acquisition space (i.e., k-space), which violate the Nyquist theorem and cause artifacts even after motion correction. These artifacts were addressed through the data redundancy provided by multiple receiver channels that is present in modern receiver coils and an iterative conjugate-gradient based reconstruction. This method was then applied to diffusion tensor imaging (DTI) with multi-shot readout. Since DTI uses directional gradients to encode diffusion, rotational motion causes the image contrast to change, and it becomes incorrect to combine data with varying diffusion encodings on them. To address this issue, a non-linear conjugate gradient based reconstruction is presented and it is shown that this method provided more accurate description of white matter pathways compared to traditional methods. In the second part of this thesis, a prospective motion correction system using an optical tracking device is presented. Such systems are preferable compared to retrospective navigator-based methods due to various reasons, such as ability to perform motion correction independent of the MR data acquisition and immunity to spin history effects. The system proposed used a single camera mounted on the head coil and a self-encoded checkerboard marker mounted on the patient's forehead. Results on structural and diffusion imaging revealed that prospective motion correction outperforms retrospective navigator-based schemes. In the last part of the thesis, entropy-based retrospective autofocusing was used in combination with motion data obtained from prospective tracking to remove residual motion artifacts in the images. This method was especially useful for removing errors caused by inaccurate cross-calibration between the scanner and camera frame-of-references. It was also shown that prospective tracking can be the enabling technology for autofocusing in 3D acquisitions.
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 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Motion Correction for Functional Magnetic Resonance Images written by Peter R. Bannister and published by . This book was released on 2004 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Statistical Analysis of Functional MRI Data written by Nicole Lazar and published by Springer Science & Business Media. This book was released on 2008-06-10 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of brain function is one of the most fascinating pursuits of m- ern science. Functional neuroimaging is an important component of much of the current research in cognitive, clinical, and social psychology. The exci- ment of studying the brain is recognized in both the popular press and the scienti?c community. In the pages of mainstream publications, including The New York Times and Wired, readers can learn about cutting-edge research into topics such as understanding how customers react to products and - vertisements (“If your brain has a ‘buy button,’ what pushes it?”, The New York Times,October19,2004),howviewersrespondtocampaignads(“Using M. R. I. ’s to see politics on the brain,” The New York Times, April 20, 2004; “This is your brain on Hillary: Political neuroscience hits new low,” Wired, November 12,2007),howmen and womenreactto sexualstimulation (“Brain scans arouse researchers,”Wired, April 19, 2004), distinguishing lies from the truth (“Duped,” The New Yorker, July 2, 2007; “Woman convicted of child abuse hopes fMRI can prove her innocence,” Wired, November 5, 2007), and even what separates “cool” people from “nerds” (“If you secretly like Michael Bolton, we’ll know,” Wired, October 2004). Reports on pathologies such as autism, in which neuroimaging plays a large role, are also common (for - stance, a Time magazine cover story from May 6, 2002, entitled “Inside the world of autism”).
Download or read book Prospective Motion Correction in MRI written by Michael Herbst and published by . This book was released on 2013 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Clinical Functional MRI written by Christoph Stippich and published by Springer. This book was released on 2015-02-27 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second, revised edition of this successful textbook provides an up-to-date description of the use of preoperative fMRI in patients with brain tumors and epilepsies. State of the art fMRI procedures are presented, with detailed consideration of practical aspects, imaging and data processing, normal and pathological findings, and diagnostic possibilities and limitations. Relevant information on brain physiology, functional neuroanatomy, imaging technique, and methodology is provided by recognized experts in these fields. Compared with the first edition, chapters have been updated to reflect the latest developments and in particular the current use of diffusion tensor imaging (DTI) and resting-state fMRI. Entirely new chapters are included on resting-state presurgical fMRI and the role of DTI and tractography in brain tumor surgery. Further chapters address multimodality functional neuroimaging, brain plasticity, and pitfalls, tips, and tricks.
Download or read book MR Imaging with Prospective Motion Correction written by Xiang Gao and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 A Navigator based Rigid Body Motion Correction for Magnetic Resonance Imaging written by Marcus Görge Ullisch and published by . This book was released on 2012 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Clinical Applications of Functional Brain MRI written by Serge A. R. B. Rombouts and published by Oxford University Press. This book was released on 2007-11-08 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past few years FMRI has become one of the most widely used methods for imaging normal brain function, in turn becoming a valuable tool in the study of many psychiatric and neurological disorders. This book provides an overview of the latest FMRI research in a number of these disorders.
Download or read book Functional Magnetic Resonance Imaging written by Ajay V. Deshmukh and published by Alpha Science International, Limited. This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Fundamental concepts, and some glimpses of the state-of-the-art of Magnetic Resonance Imaging (MRI) and functional MRI (fMRI) are discussed in this monograph. A discussion on novel transform methods using Wavelets and the Periodicity Transform for processing the clinical fMRI data is included. The book describes results on the original functional MRI data set. This trial fMRI dataset is provided on a CD included in this book. Making free use of this data set for further experimentation on fMRI for academic and research purpose is highly encouraged. Algorithms on a few worked examples on fMRI data processing are explained. Presentation of certain concepts in MRI and Functional MRI is made simple for the readers from interdisciplinary areas of Medical Sciences and Engineering. This book is also an effort to address a few real-life examples in fMRI which have been evolved through collaborative research by the Engineering and Medical fraternity."--BOOK JACKET.
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:
