Filters








3,450 Hits in 8.3 sec

Motion artifact reduction in pediatric diffusion tensor imaging using fast prospective correction

A. Alhamud, Paul A. Taylor, Barbara Laughton, André J.W. van der Kouwe, Ernesta M. Meintjes
2014 Journal of Magnetic Resonance Imaging  
Conclusion-Due to the heterogeneity of brain structures and the comparatively low resolution (~2 mm) of diffusion data using 2D single shot sequencing, retrospective motion correction is susceptible to  ...  We investigate changes that both retrospective (with and without diffusion table reorientation) and prospective (implemented with a short navigator sequence) motion correction induce in the resulting diffusion  ...  of retrospective motion correction, and the prospectively motion-corrected navigated diffusion sequence with reacquisition.  ... 
doi:10.1002/jmri.24678 pmid:24935904 pmcid:PMC4269573 fatcat:i5onrdn54zf53cahofyvoocsae

Volumetric navigators for real-time motion correction in diffusion tensor imaging

A. Alhamud, M. Dylan Tisdall, Aaron T. Hess, Khader M. Hasan, Ernesta M. Meintjes, André J.W. van der Kouwe
2012 Magnetic Resonance in Medicine  
Retrospective techniques have many limitations in the coregistration of conventional MR images, including blurring artifacts (7) and the influence of through-plane motion on the local history of magnetization  ...  Water phantom and human brain data were acquired using the standard and navigated diffusion sequences, and the mean and whole brain histogram of the fractional anisotropy and mean diffusivity were analyzed  ...  Retrospective techniques have many limitations in the coregistration of conventional MR images, including blurring artifacts (7) and the influence of through-plane motion on the local history of magnetization  ... 
doi:10.1002/mrm.23314 pmid:22246720 pmcid:PMC3330197 fatcat:4prrspfaxrfutgjhrvl3qipyru

Prospective motion correction in brain imaging: A review

Julian Maclaren, Michael Herbst, Oliver Speck, Maxim Zaitsev
2012 Magnetic Resonance in Medicine  
ACKNOWLEDGMENTS The authors thank Murat Aksoy, Roland Bammer, Melvyn Ooi, and Jessica Schulz for their assistance.  ...  In conclusion, the recent developments in prospective motion correction have demonstrated that the technique has the potential to help solve what is still a very real problem in MRI and magnetic resonance  ...  In proton magnetic resonance spectroscopy, prospective motion correction has been shown to reduce spectral artifacts and quantitation errors in choline/creatine ratios (25) and reduce lipid contamination  ... 
doi:10.1002/mrm.24314 pmid:22570274 fatcat:yyav36eqnvdfhlbya4f3s7d4xq

Combined prospective and retrospective correction to reduce motion-induced image misalignment and geometric distortions in EPI

Melvyn B. Ooi, Jordan Muraskin, Xiaowei Zou, William J. Thomas, Sascha Krueger, Murat Aksoy, Roland Bammer, Truman R. Brown
2012 Magnetic Resonance in Medicine  
This combined method is applied to compensate EPI scans of volunteers performing in-plane and through-plane head motions, resulting in increased image stability beyond what either prospective or retrospective  ...  The current work presents a combined prospective/retrospective solution to reduce both rigid and non-rigid components of this motionrelated image misalignment.  ...  INTRODUCTION Head motion is a familiar and significant problem for magnetic resonance imaging (MRI) studies such as diffusion, perfusion, and functional MRI (fMRI) that acquire multiple frames of the same  ... 
doi:10.1002/mrm.24285 pmid:22499027 pmcid:PMC3402592 fatcat:cwjxeo3m4rdhrohwnevbxka34i

Assessing the performance of different DTI motion correction strategies in the presence of EPI distortion correction

Paul A. Taylor, A. Alhamud, Andre van der Kouwe, Muhammad G. Saleh, Barbara Laughton, Ernesta Meintjes
2016 Human Brain Mapping  
The inclusion of both prospective and retrospective motion correction with EPI distortion correction is important for DTI analysis, particularly when studying subject populations that are prone to motion  ...  Diffusion tensor imaging (DTI) is susceptible to several artifacts due to eddy currents, echo planar imaging (EPI) distortion and subject motion.  ...  APPENDIX A Inversion of the relative contrast of tissues (IRCT): an approach for creating reference volumes for diffusion weighted MR images from T1w anatomical acquisitions.  ... 
doi:10.1002/hbm.23318 pmid:27436169 pmcid:PMC5118068 fatcat:7skkdxim6jci3k6nd5ei4mqwe4

Mapping Fetal Brain Development In Utero Using Magnetic Resonance Imaging: The Big Bang of Brain Mapping

Colin Studholme
2011 Annual Review of Biomedical Engineering  
The development of tools to construct and investigate probabilistic maps of the adult human brain from magnetic resonance imaging (MRI) has led to advances in both basic neuroscience and clinical diagnosis  ...  This article reviews the developments that have led us to this point, examines the current state of the art in the fields of fast fetal imaging and motion correction, and describes the tools to analyze  ...  These have been used for both retrospective (63) and prospective (64) correction of motion and can employ a variety of k-space trajectory shapes to measure motion in different axes, including linear  ... 
doi:10.1146/annurev-bioeng-071910-124654 pmid:21568716 pmcid:PMC3682118 fatcat:bfgd3cj33jfipa67t3ssm3x4ry

Properties of a 2D fat navigator for prospective image domain correction of nodding motion in brain MRI

Stefan Skare, Axel Hartwig, Magnus Mårtensson, Enrico Avventi, Mathias Engström
2014 Magnetic Resonance in Medicine  
Magnetic resonance imaging is one of the fastest developing medical imaging techniques.  ...  One of the possible MR imaging contrasts is the ability to visualize diffusion processes.  ...  There are two main categories of motion correction, retrospective correction (where the data is corrected during the image reconstruction phase), and prospective correction (where the acquisition is updated  ... 
doi:10.1002/mrm.25234 pmid:24733744 fatcat:edimpyjaafad7bnjtfem4datrm

Motion correction in MRI of the brain

F Godenschweger, U Kägebein, D Stucht, U Yarach, A Sciarra, R Yakupov, F Lüsebrink, P Schulze, O Speck
2016 Physics in Medicine and Biology  
Retrospective motion correction modifies the MR image data during the reconstruction, while prospective motion correction performs an adaptive update of the data acquisition.  ...  This review focuses on rigid body motion correction of head and brain MRI and its application in diagnosis and research.  ...  of the European Commission (FP7-PEOPLE-2012-ITN-316716) and NIH grant R01DA021146.  ... 
doi:10.1088/0031-9155/61/5/r32 pmid:26864183 pmcid:PMC4930872 fatcat:lqh4phs4bnfmrjpddrf7sbmimm

Simultaneous T2 and biexponential diffusion analysis in breast lesion

Masako TAKANAGA, Tosiaki MIYATI, Naoki OHNO, Hiroko KAWASHIMA, Norio HAYASHI, Yukihiro MATSUURA, Toshifumi GABATA
2015 Medical Imaging and Information Sciences  
The aim of this study was to propose simultaneous analysis of effective transverse relaxation time(T2)and biexponential diffusion parameters for breast magnetic resonance imaging(MRI)using conventional  ...  The T2 correction of DW images were performed using diffusion echo-planar imaging-T2-weighted images with multiple TE because TE increased with increasing b values.  ...  Introduction Magnetic resonance imaging(MRI)is an important tool for the detection and characterization of breast lesions.  ... 
doi:10.11318/mii.32.1 fatcat:dreyp5clufgvtmcvhjpdvl6ohq

Repeatability and reproducibility of prospective motion- and shim corrected 2D glycoCEST MRI

Gizeaddis Lamesgin Simegn, Ali Alhamud, Andre J. W. van der Kouwe, Ernesta Meintjes, Frances Robertson
2019 Quantitative Imaging in Medicine and Surgery  
- and motion correction applied.  ...  In nine subjects, double volumetric navigated (DvNav)-CEST acquisitions in the calf muscle were repeated five times in each of two sessions-the first without correction, and the second with real-time shim  ...  and gray and white matter glutamate contrast in the human brain (31) .  ... 
doi:10.21037/qims.2019.09.15 pmid:31728311 pmcid:PMC6828578 fatcat:ugeaykmzv5eprkif7wsjpnm34m

Diffusion Tensor Imaging (DTI) and Colored Fractional Anisotropy (FA) Mapping of the Ventralis Intermedius (VIM) Nucleus of the Thalamus

Mark Sedrak, Alessandra Gorgulho, Andrew Frew, Eric Behnke, Antonio DeSalles, Nader Pouratian
2011 Neurosurgery  
OBJECTIVE: To study colored fractional anisotropic images and diffusion tensor imaging (DTI) tractography to identify characteristic magnetic resonance appearances of the VIM nucleus.  ...  METHODS: Four patients undergoing stereotactic surgery for essential tremor (ET) were retrospectively studied with analysis of magnetic resonance imaging-based colored fractional anisotropy (FA) images  ...  Various structures have been identified and labeled in the image obtained on 1.5-T magnetic resonance imaging.  ... 
doi:10.1227/neu.0b013e3182296a42 pmid:21697755 fatcat:mmxnfml2a5cx7kmi354uzk4crm

Motion artifacts in MRI: A complex problem with many partial solutions

Maxim Zaitsev, Julian Maclaren, Michael Herbst
2015 Journal of Magnetic Resonance Imaging  
Subject motion during magnetic resonance imaging (MRI) has been problematic since its introduction as a clinical imaging modality.  ...  In this review, we first examine the physical origins of motion artefacts and then summarize the main motion prevention and correction tools currently in use or in development.  ...  Acknowledgments Grant support: NIH grant numbers 1R01 DA021146, 2R01 DA021146, 5R01 EB011654 and 5R21 EB017616 Alexander von Humboldt foundation  ... 
doi:10.1002/jmri.24850 pmid:25630632 pmcid:PMC4517972 fatcat:zzzzofenlra7bnly2omhamd75q

Real-time measurement and correction of both B0 changes and subject motion in diffusion tensor imaging using a double volumetric navigated (DvNav) sequence

A. Alhamud, Paul A. Taylor, Andre J.W. van der Kouwe, Ernesta M. Meintjes
2016 NeuroImage  
methods for correcting ΔB0 effects in EPI Several techniques have been proposed to correct ΔB0 effects in EPI, including the use of specific hardware and both prospective and retrospective methods.  ...  Diffusion tensor imaging (DTI) requires a set of diffusion weighted measurements in order to acquire enough information to characterize local structure.  ...  We observed that shim correction of the human brain is not completely stable by the 2 nd DTI volume, possibly due to motion-shim interactions, whereas in the water phantom scans the shim correction appeared  ... 
doi:10.1016/j.neuroimage.2015.11.022 pmid:26584865 pmcid:PMC4733594 fatcat:mo5da6qzpvgarnnhxelt7rf4eu

Inherent correction of motion-induced phase errors in multishot spiral diffusion-weighted imaging

Trong-Kha Truong, Nan-kuei Chen, Allen W. Song
2011 Magnetic Resonance in Medicine  
by rigid-body motion in multi-shot spiral diffusion-weighted imaging of the human brain.  ...  However, subject motion in the presence of diffusion-weighting gradients causes phase inconsistencies among different shots, resulting in signal loss and aliasing artifacts in the reconstructed images.  ...  This work was, in part, supported by grants NS41328, NS65344, EB09483, and EB12586 from the National Institutes of Health.  ... 
doi:10.1002/mrm.24124 pmid:22222689 pmcid:PMC3323687 fatcat:sunypnstv5fpzc3axjrynojf7u

Prospective motion correction of high-resolution magnetic resonance imaging data in children

Timothy T. Brown, Joshua M. Kuperman, Matthew Erhart, Nathan S. White, J. Cooper Roddey, Ajit Shankaranarayanan, Eric T. Han, Dan Rettmann, Anders M. Dale
2010 NeuroImage  
Motion artifacts pose significant problems for the acquisition and analysis of high-resolution magnetic resonance imaging data.  ...  In this study, we tested the effectiveness of a new prospective motion correction technique, called PROMO, as applied to making neuroanatomical measures in typically developing school-age children.  ...  for Brain and Mind to Tim Brown.  ... 
doi:10.1016/j.neuroimage.2010.06.017 pmid:20542120 pmcid:PMC3146240 fatcat:rhwey2qxyjbibnijtjrdlgyowq
« Previous Showing results 1 — 15 out of 3,450 results