201
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Afacan O, Erem B, Roby DP, Roth N, Roth A, Prabhu SP, Warfield SK. Evaluation of motion and its effect on brain magnetic resonance image quality in children. Pediatr Radiol 2016; 46:1728-1735. [PMID: 27488508 PMCID: PMC5083190 DOI: 10.1007/s00247-016-3677-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 06/02/2016] [Accepted: 07/20/2016] [Indexed: 11/26/2022]
Abstract
BACKGROUND Motion artifacts pose significant problems for the acquisition of MR images in pediatric populations. OBJECTIVE To evaluate temporal motion metrics in MRI scanners and their effect on image quality in pediatric populations in neuroimaging studies. MATERIALS AND METHODS We report results from a large pediatric brain imaging study that shows the effect of motion on MRI quality. We measured motion metrics in 82 pediatric patients, mean age 13.4 years, in a T1-weighted brain MRI scan. As a result of technical difficulties, 5 scans were not included in the subsequent analyses. A radiologist graded the images using a 4-point scale ranging from clinically non-diagnostic because of motion artifacts to no motion artifacts. We used these grades to correlate motion parameters such as maximum motion, mean displacement from a reference point, and motion-free time with image quality. RESULTS Our results show that both motion-free time (as a ratio of total scan time) and average displacement from a position at a fixed time (when the center of k-space was acquired) were highly correlated with image quality, whereas maximum displacement was not as good a predictor. Among the 77 patients whose motion was measured successfully, 17 had average displacements of greater than 0.5 mm, and 11 of those (14.3%) resulted in non-diagnostic images. Similarly, 14 patients (18.2%) had less than 90% motion-free time, which also resulted in non-diagnostic images. CONCLUSION We report results from a large pediatric study to show how children and young adults move in the MRI scanner and the effect that this motion has on image quality. The results will help the motion-correction community in better understanding motion patterns in pediatric populations and how these patterns affect MR image quality.
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Affiliation(s)
- Onur Afacan
- Department of Radiology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Ave., WB215, Boston, MA, 02115, USA.
| | - Burak Erem
- Department of Radiology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Ave., WB215, Boston, MA, 02115, USA
| | - Diona P Roby
- Department of Radiology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Ave., WB215, Boston, MA, 02115, USA
| | - Noam Roth
- Robin Medical Inc., Baltimore, MD, USA
| | - Amir Roth
- Robin Medical Inc., Baltimore, MD, USA
| | - Sanjay P Prabhu
- Department of Radiology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Ave., WB215, Boston, MA, 02115, USA
| | - Simon K Warfield
- Department of Radiology, Boston Children's Hospital and Harvard Medical School, 300 Longwood Ave., WB215, Boston, MA, 02115, USA
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202
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Fehlner A, Hirsch S, Weygandt M, Christophel T, Barnhill E, Kadobianskyi M, Braun J, Bernarding J, Lützkendorf R, Sack I, Hetzer S. Increasing the spatial resolution and sensitivity of magnetic resonance elastography by correcting for subject motion and susceptibility-induced image distortions. J Magn Reson Imaging 2016; 46:134-141. [DOI: 10.1002/jmri.25516] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Accepted: 10/05/2016] [Indexed: 12/13/2022] Open
Affiliation(s)
- Andreas Fehlner
- Department of Radiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Sebastian Hirsch
- Institute of Medical Informatics; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Martin Weygandt
- Berlin Center for Advanced Neuroimaging; Charité - Universitätsmedizin Berlin; Berlin Germany
- Bernstein Center for Computational Neuroscience; Berlin Germany
| | - Thomas Christophel
- Berlin Center for Advanced Neuroimaging; Charité - Universitätsmedizin Berlin; Berlin Germany
- Bernstein Center for Computational Neuroscience; Berlin Germany
| | - Eric Barnhill
- Department of Radiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Mykola Kadobianskyi
- Berlin Center for Advanced Neuroimaging; Charité - Universitätsmedizin Berlin; Berlin Germany
- Bernstein Center for Computational Neuroscience; Berlin Germany
| | - Jürgen Braun
- Institute of Medical Informatics; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Johannes Bernarding
- Institute of Biometry and Medical Informatics; Otto-von-Guericke University; Magdeburg Germany
| | - Ralf Lützkendorf
- Institute of Biometry and Medical Informatics; Otto-von-Guericke University; Magdeburg Germany
| | - Ingolf Sack
- Department of Radiology; Charité - Universitätsmedizin Berlin; Berlin Germany
| | - Stefan Hetzer
- Berlin Center for Advanced Neuroimaging; Charité - Universitätsmedizin Berlin; Berlin Germany
- Bernstein Center for Computational Neuroscience; Berlin Germany
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203
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Tavallaei MA, Johnson PM, Liu J, Drangova M. Design and evaluation of an MRI-compatible linear motion stage. Med Phys 2016; 43:62. [PMID: 26745900 DOI: 10.1118/1.4937780] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
PURPOSE To develop and evaluate a tool for accurate, reproducible, and programmable motion control of imaging phantoms for use in motion sensitive magnetic resonance imaging (MRI) appli cations. METHODS In this paper, the authors introduce a compact linear motion stage that is made of nonmagnetic material and is actuated with an ultrasonic motor. The stage can be positioned at arbitrary positions and orientations inside the scanner bore to move, push, or pull arbitrary phantoms. Using optical trackers, measuring microscopes, and navigators, the accuracy of the stage in motion control was evaluated. Also, the effect of the stage on image signal-to-noise ratio (SNR), artifacts, and B0 field homogeneity was evaluated. RESULTS The error of the stage in reaching fixed positions was 0.025 ± 0.021 mm. In execution of dynamic motion profiles, the worst-case normalized root mean squared error was below 7% (for frequencies below 0.33 Hz). Experiments demonstrated that the stage did not introduce artifacts nor did it degrade the image SNR. The effect of the stage on the B0 field was less than 2 ppm. CONCLUSIONS The results of the experiments indicate that the proposed system is MRI-compatible and can create reliable and reproducible motion that may be used for validation and assessment of motion related MRI applications.
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Affiliation(s)
- Mohammad Ali Tavallaei
- Imaging Research Laboratories, Robarts Research Institute, The University of Western Ontario, London, Ontario N6A 5B7, Canada and Biomedical Engineering Graduate Program, The University of Western Ontario, London, Ontario N6A 5B9, Canada
| | - Patricia M Johnson
- Imaging Research Laboratories, Robarts Research Institute, The University of Western Ontario, London, Ontario N6A 5B7, Canada and Department of Medical Biophysics, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Junmin Liu
- Imaging Research Laboratories, Robarts Research Institute, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Maria Drangova
- Imaging Research Laboratories, Robarts Research Institute, The University of Western Ontario, London, Ontario N6A 5B7, Canada; Biomedical Engineering Graduate Program, The University of Western Ontario, London, Ontario N6A 5B9, Canada; and Department of Medical Biophysics, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario N6A 5C1, Canada
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204
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Marami B, Scherrer B, Afacan O, Erem B, Warfield SK, Gholipour A. Motion-Robust Diffusion-Weighted Brain MRI Reconstruction Through Slice-Level Registration-Based Motion Tracking. IEEE TRANSACTIONS ON MEDICAL IMAGING 2016; 35:2258-2269. [PMID: 27834639 PMCID: PMC5108524 DOI: 10.1109/tmi.2016.2555244] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This work proposes a novel approach for motion-robust diffusion-weighted (DW) brain MRI reconstruction through tracking temporal head motion using slice-to-volume registration. The slice-level motion is estimated through a filtering approach that allows tracking the head motion during the scan and correcting for out-of-plane inconsistency in the acquired images. Diffusion-sensitized image slices are registered to a base volume sequentially over time in the acquisition order where an outlier-robust Kalman filter, coupled with slice-to-volume registration, estimates head motion parameters. Diffusion gradient directions are corrected for the aligned DWI slices based on the computed rotation parameters and the diffusion tensors are directly estimated from the corrected data at each voxel using weighted linear least squares. The method was evaluated in DWI scans of adult volunteers who deliberately moved during scans as well as clinical DWI of 28 neonates and children with different types of motion. Experimental results showed marked improvements in DWI reconstruction using the proposed method compared to the state-of-the-art DWI analysis based on volume-to-volume registration. This approach can be readily used to retrieve information from motion-corrupted DW imaging data.
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Affiliation(s)
- Bahram Marami
- Department of Radiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA 02115 USA
| | - Benoit Scherrer
- Department of Radiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA 02115 USA
| | - Onur Afacan
- Department of Radiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA 02115 USA
| | - Burak Erem
- Department of Radiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA 02115 USA
| | - Simon K. Warfield
- Department of Radiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA 02115 USA
| | - Ali Gholipour
- Department of Radiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA 02115 USA
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205
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Self-navigated 4D cartesian imaging of periodic motion in the body trunk using partial k-space compressed sensing. Magn Reson Med 2016; 78:632-644. [DOI: 10.1002/mrm.26406] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 08/04/2016] [Accepted: 08/10/2016] [Indexed: 12/28/2022]
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206
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Hughes EJ, Winchman T, Padormo F, Teixeira R, Wurie J, Sharma M, Fox M, Hutter J, Cordero-Grande L, Price AN, Allsop J, Bueno-Conde J, Tusor N, Arichi T, Edwards AD, Rutherford MA, Counsell SJ, Hajnal JV. A dedicated neonatal brain imaging system. Magn Reson Med 2016; 78:794-804. [PMID: 27643791 PMCID: PMC5516134 DOI: 10.1002/mrm.26462] [Citation(s) in RCA: 174] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 08/16/2016] [Accepted: 08/20/2016] [Indexed: 11/06/2022]
Abstract
PURPOSE The goal of the Developing Human Connectome Project is to acquire MRI in 1000 neonates to create a dynamic map of human brain connectivity during early development. High-quality imaging in this cohort without sedation presents a number of technical and practical challenges. METHODS We designed a neonatal brain imaging system (NBIS) consisting of a dedicated 32-channel receive array coil and a positioning device that allows placement of the infant's head deep into the coil for maximum signal-to-noise ratio (SNR). Disturbance to the infant was minimized by using an MRI-compatible trolley to prepare and transport the infant and by employing a slow ramp-up and continuation of gradient noise during scanning. Scan repeats were minimized by using a restart capability for diffusion MRI and retrospective motion correction. We measured the 1) SNR gain, 2) number of infants with a completed scan protocol, and 3) number of anatomical images with no motion artifact using NBIS compared with using an adult 32-channel head coil. RESULTS The NBIS has 2.4 times the SNR of the adult coil and 90% protocol completion rate. CONCLUSION The NBIS allows advanced neonatal brain imaging techniques to be employed in neonatal brain imaging with high protocol completion rates. Magn Reson Med 78:794-804, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
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Affiliation(s)
- Emer J Hughes
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
| | | | - Francesco Padormo
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
| | - Rui Teixeira
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
| | - Julia Wurie
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
| | - Maryanne Sharma
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
| | - Matthew Fox
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
| | - Jana Hutter
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
| | - Lucilio Cordero-Grande
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
| | - Anthony N Price
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
| | - Joanna Allsop
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
| | - Jose Bueno-Conde
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
| | - Nora Tusor
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
| | - Tomoki Arichi
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
| | - A D Edwards
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
| | - Mary A Rutherford
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
| | - Serena J Counsell
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
| | - Joseph V Hajnal
- Centre for the Developing Brain, Perinatal Imaging and Health, Imaging Sciences and Biomedical Engineering Division, Kings College, London, United Kingdom
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207
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Liu TT. Noise contributions to the fMRI signal: An overview. Neuroimage 2016; 143:141-151. [PMID: 27612646 DOI: 10.1016/j.neuroimage.2016.09.008] [Citation(s) in RCA: 148] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 09/01/2016] [Accepted: 09/03/2016] [Indexed: 01/21/2023] Open
Abstract
The ability to discriminate signal from noise plays a key role in the analysis and interpretation of functional magnetic resonance imaging (fMRI) measures of brain activity. Over the past two decades, a number of major sources of noise have been identified, including system-related instabilities, subject motion, and physiological fluctuations. This article reviews the characteristics of the various noise sources as well as the mechanisms through which they affect the fMRI signal. Approaches for distinguishing signal from noise and the associated challenges are also reviewed. These challenges reflect the fact that some noise sources, such as respiratory activity, are generated by the same underlying brain networks that give rise to functional signals that are of interest.
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Affiliation(s)
- Thomas T Liu
- Center for Functional MRI, University of California San Diego, 9500 Gilman Drive MC 0677, La Jolla, CA 92093, United States; Departments of Radiology, Psychiatry and Bioengineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, United States.
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208
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Patriat R, Reynolds RC, Birn RM. An improved model of motion-related signal changes in fMRI. Neuroimage 2016; 144:74-82. [PMID: 27570108 DOI: 10.1016/j.neuroimage.2016.08.051] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 07/22/2016] [Accepted: 08/24/2016] [Indexed: 11/16/2022] Open
Abstract
Head motion is a significant source of noise in the estimation of functional connectivity from resting-state functional MRI (rs-fMRI). Current strategies to reduce this noise include image realignment, censoring time points corrupted by motion, and including motion realignment parameters and their derivatives as additional nuisance regressors in the general linear model. However, this nuisance regression approach assumes that the motion-induced signal changes are linearly related to the estimated realignment parameters, which is not always the case. In this study we develop an improved model of motion-related signal changes, where nuisance regressors are formed by first rotating and translating a single brain volume according to the estimated motion, re-registering the data, and then performing a principal components analysis (PCA) on the resultant time series of both moved and re-registered data. We show that these "Motion Simulated (MotSim)" regressors account for significantly greater fraction of variance, result in higher temporal signal-to-noise, and lead to functional connectivity estimates that are less affected by motion compared to the most common current approach of using the realignment parameters and their derivatives as nuisance regressors. This improvement should lead to more accurate estimates of functional connectivity, particularly in populations where motion is prevalent, such as patients and young children.
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Affiliation(s)
- Rémi Patriat
- Department of Medical Physics, University of Wisconsin, Madison, USA
| | - Richard C Reynolds
- Scientific and Statistical Computing Core, National Institute of Mental Health, National Institutes of Health, Bethesda, USA
| | - Rasmus M Birn
- Department of Medical Physics, University of Wisconsin, Madison, USA; Department of Psychiatry, University of Wisconsin, Madison, USA.
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209
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Pardoe HR, Kucharsky Hiess R, Kuzniecky R. Motion and morphometry in clinical and nonclinical populations. Neuroimage 2016; 135:177-85. [DOI: 10.1016/j.neuroimage.2016.05.005] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 04/17/2016] [Accepted: 05/02/2016] [Indexed: 10/21/2022] Open
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210
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Layton KJ, Kroboth S, Jia F, Littin S, Yu H, Leupold J, Nielsen JF, Stöcker T, Zaitsev M. Pulseq: A rapid and hardware-independent pulse sequence prototyping framework. Magn Reson Med 2016; 77:1544-1552. [DOI: 10.1002/mrm.26235] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 02/12/2016] [Accepted: 03/11/2016] [Indexed: 11/12/2022]
Affiliation(s)
- Kelvin J. Layton
- Department of Radiology; Medical Physics, University Medical Center Freiburg; Freiburg BW Germany
| | - Stefan Kroboth
- Department of Radiology; Medical Physics, University Medical Center Freiburg; Freiburg BW Germany
| | - Feng Jia
- Department of Radiology; Medical Physics, University Medical Center Freiburg; Freiburg BW Germany
| | - Sebastian Littin
- Department of Radiology; Medical Physics, University Medical Center Freiburg; Freiburg BW Germany
| | - Huijun Yu
- Department of Radiology; Medical Physics, University Medical Center Freiburg; Freiburg BW Germany
| | - Jochen Leupold
- Department of Radiology; Medical Physics, University Medical Center Freiburg; Freiburg BW Germany
| | - Jon-Fredrik Nielsen
- Department of Biomedical Engineering; University of Michigan; Ann Arbor Michigan USA
| | - Tony Stöcker
- German Center for Neurodegenerative Diseases; Bonn NRW Germany
| | - Maxim Zaitsev
- Department of Radiology; Medical Physics, University Medical Center Freiburg; Freiburg BW Germany
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211
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Maziero D, Velasco TR, Hunt N, Payne E, Lemieux L, Salmon CEG, Carmichael DW. Towards motion insensitive EEG-fMRI: Correcting motion-induced voltages and gradient artefact instability in EEG using an fMRI prospective motion correction (PMC) system. Neuroimage 2016; 138:13-27. [PMID: 27157789 DOI: 10.1016/j.neuroimage.2016.05.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 04/05/2016] [Accepted: 05/01/2016] [Indexed: 11/17/2022] Open
Abstract
The simultaneous acquisition of electroencephalography and functional magnetic resonance imaging (EEG-fMRI) is a multimodal technique extensively applied for mapping the human brain. However, the quality of EEG data obtained within the MRI environment is strongly affected by subject motion due to the induction of voltages in addition to artefacts caused by the scanning gradients and the heartbeat. This has limited its application in populations such as paediatric patients or to study epileptic seizure onset. Recent work has used a Moiré-phase grating and a MR-compatible camera to prospectively update image acquisition and improve fMRI quality (prospective motion correction: PMC). In this study, we use this technology to retrospectively reduce the spurious voltages induced by motion in the EEG data acquired inside the MRI scanner, with and without fMRI acquisitions. This was achieved by modelling induced voltages from the tracking system motion parameters; position and angles, their first derivative (velocities) and the velocity squared. This model was used to remove the voltages related to the detected motion via a linear regression. Since EEG quality during fMRI relies on a temporally stable gradient artefact (GA) template (calculated from averaging EEG epochs matched to scan volume or slice acquisition), this was evaluated in sessions both with and without motion contamination, and with and without PMC. We demonstrate that our approach is capable of significantly reducing motion-related artefact with a magnitude of up to 10mm of translation, 6° of rotation and velocities of 50mm/s, while preserving physiological information. We also demonstrate that the EEG-GA variance is not increased by the gradient direction changes associated with PMC. Provided a scan slice-based GA template is used (rather than a scan volume GA template) we demonstrate that EEG variance during motion can be supressed towards levels found when subjects are still. In summary, we show that PMC can be used to dramatically improve EEG quality during large amplitude movements, while benefiting from previously reported improvements in fMRI quality, and does not affect EEG data quality in the absence of large amplitude movements.
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Affiliation(s)
- Danilo Maziero
- Developmental Imaging and Biophysics Section, UCL Institute of Child Health, London, UK; InBrain Lab, Department of Physics, FFLCRP, University of São Paulo, Ribeirão Preto, SP, Brazil.
| | - Tonicarlo R Velasco
- Epilepsy Surgery Centre, Department of Neuroscience, Faculty of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Nigel Hunt
- Division of Craniofacial Developmental Sciences, UCL Eastman Dental Institute, London, UK
| | - Edwin Payne
- Division of Craniofacial Developmental Sciences, UCL Eastman Dental Institute, London, UK
| | - Louis Lemieux
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, UK
| | - Carlos E G Salmon
- InBrain Lab, Department of Physics, FFLCRP, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - David W Carmichael
- Developmental Imaging and Biophysics Section, UCL Institute of Child Health, London, UK
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212
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Hock A, Henning A. Motion correction and frequency stabilization for MRS of the human spinal cord. NMR IN BIOMEDICINE 2016; 29:490-498. [PMID: 26867133 DOI: 10.1002/nbm.3487] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 12/15/2015] [Accepted: 12/20/2015] [Indexed: 06/05/2023]
Abstract
Subject motion is challenging for MRS, because it can falsify results. For spinal cord MRS in particular, subject movement is critical, since even a small movement > 1 mm) can lead to a voxel shift out of the desired measurement region. Therefore, the identification of motion corrupted MRS scans is essential. In this investigation, MR navigators acquired simultaneously with the MRS data are used to identify a displacement of the spinal cord due to subject motion. It is shown that navigators are able to recognize substantial subject motion (>1 mm) without impairing the MRS measurement. In addition, navigators are easy to apply to the measurement, because no additional hardware and just a minor additional user effort are needed. Moreover, no additional scan time is required, because navigators can be applied in the deadtime of the MRS sequence. Furthermore, in this work, retrospective motion correction combined with frequency stabilization is presented by combining navigators with non-water-suppressed (1)H-MRS, resulting in an improved spectral quality of the spinal cord measurements.
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Affiliation(s)
- Andreas Hock
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
- Department of Psychiatry, Psychotherapy and Psychosomatics, Hospital of Psychiatry, University of Zurich, Zurich, Switzerland
| | - Anke Henning
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
- Max Plank Institute for Biological Cybernetics, Tuebingen, Germany
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213
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Bonte M, Ley A, Scharke W, Formisano E. Developmental refinement of cortical systems for speech and voice processing. Neuroimage 2016; 128:373-384. [PMID: 26777479 DOI: 10.1016/j.neuroimage.2016.01.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 12/15/2015] [Accepted: 01/06/2016] [Indexed: 01/31/2023] Open
Affiliation(s)
- Milene Bonte
- Department of Cognitive Neuroscience and Maastricht Brain Imaging Center, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.
| | - Anke Ley
- Department of Cognitive Neuroscience and Maastricht Brain Imaging Center, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands
| | - Wolfgang Scharke
- Department of Cognitive Neuroscience and Maastricht Brain Imaging Center, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands
| | - Elia Formisano
- Department of Cognitive Neuroscience and Maastricht Brain Imaging Center, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands
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214
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Godenschweger F, Kägebein U, Stucht D, Yarach U, Sciarra A, Yakupov R, Lüsebrink F, Schulze P, Speck O. Motion correction in MRI of the brain. Phys Med Biol 2016; 61:R32-56. [PMID: 26864183 DOI: 10.1088/0031-9155/61/5/r32] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Subject motion in MRI is a relevant problem in the daily clinical routine as well as in scientific studies. Since the beginning of clinical use of MRI, many research groups have developed methods to suppress or correct motion artefacts. This review focuses on rigid body motion correction of head and brain MRI and its application in diagnosis and research. It explains the sources and types of motion and related artefacts, classifies and describes existing techniques for motion detection, compensation and correction and lists established and experimental approaches. Retrospective motion correction modifies the MR image data during the reconstruction, while prospective motion correction performs an adaptive update of the data acquisition. Differences, benefits and drawbacks of different motion correction methods are discussed.
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Affiliation(s)
- F Godenschweger
- Biomedical Magnetic Resonance, Otto-von-Guericke University, Magdeburg, Germany
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215
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Yarach U, Luengviriya C, Stucht D, Godenschweger F, Schulze P, Speck O. Correction of B 0-induced geometric distortion variations in prospective motion correction for 7T MRI. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2016; 29:319-32. [PMID: 26861047 DOI: 10.1007/s10334-015-0515-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 11/20/2015] [Accepted: 11/21/2015] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Prospective motion correction can effectively fix the imaging volume of interest. For large motion, this can lead to relative motion of coil sensitivities, distortions associated with imaging gradients and B 0 field variations. This work accounts for the B 0 field change due to subject movement, and proposes a method for correcting tissue magnetic susceptibility-related distortion in prospective motion correction. MATERIALS AND METHODS The B 0 field shifts at the different head orientations were characterized. A volunteer performed large motion with prospective motion correction enabled. The acquired data were divided into multiple groups according to the object positions. The correction of B 0-related distortion was applied to each group of data individually via augmented sensitivity encoding with additionally integrated gradient nonlinearity correction. RESULTS The relative motion of the gradients, B 0 field and coil sensitivities in prospective motion correction results in residual spatial distortion, blurring, and coil artifacts. These errors can be mitigated by the proposed method. Moreover, iterative conjugate gradient optimization with regularization provided superior results with smaller RMSE in comparison to standard conjugate gradient. CONCLUSION The combined correction of B 0-related distortion and gradient nonlinearity leads to a reduction of residual motion artifacts in prospective motion correction data.
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Affiliation(s)
- Uten Yarach
- Department of Biomedical Magnetic Resonance, Otto-von-Guericke University Magdeburg, Leipziger Str. 44 (Haus 65), 39120, Magdeburg, Germany. .,Department of Radiological Technology, Chiangmai University, Chiang Mai, Thailand.
| | | | - Daniel Stucht
- Department of Biomedical Magnetic Resonance, Otto-von-Guericke University Magdeburg, Leipziger Str. 44 (Haus 65), 39120, Magdeburg, Germany
| | - Frank Godenschweger
- Department of Biomedical Magnetic Resonance, Otto-von-Guericke University Magdeburg, Leipziger Str. 44 (Haus 65), 39120, Magdeburg, Germany
| | - Peter Schulze
- Department of Biomedical Magnetic Resonance, Otto-von-Guericke University Magdeburg, Leipziger Str. 44 (Haus 65), 39120, Magdeburg, Germany.,German Centre for Neurodegenerative Diseases (DZNE), Site Magdeburg, Magdeburg, Germany
| | - Oliver Speck
- Department of Biomedical Magnetic Resonance, Otto-von-Guericke University Magdeburg, Leipziger Str. 44 (Haus 65), 39120, Magdeburg, Germany.,Leibniz Institute for Neurobiology, Magdeburg, Germany.,German Centre for Neurodegenerative Diseases (DZNE), Site Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
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216
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Andersson JLR, Sotiropoulos SN. An integrated approach to correction for off-resonance effects and subject movement in diffusion MR imaging. Neuroimage 2016; 125:1063-1078. [PMID: 26481672 PMCID: PMC4692656 DOI: 10.1016/j.neuroimage.2015.10.019] [Citation(s) in RCA: 2163] [Impact Index Per Article: 270.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 09/23/2015] [Accepted: 10/09/2015] [Indexed: 01/02/2023] Open
Abstract
In this paper we describe a method for retrospective estimation and correction of eddy current (EC)-induced distortions and subject movement in diffusion imaging. In addition a susceptibility-induced field can be supplied and will be incorporated into the calculations in a way that accurately reflects that the two fields (susceptibility- and EC-induced) behave differently in the presence of subject movement. The method is based on registering the individual volumes to a model free prediction of what each volume should look like, thereby enabling its use on high b-value data where the contrast is vastly different in different volumes. In addition we show that the linear EC-model commonly used is insufficient for the data used in the present paper (high spatial and angular resolution data acquired with Stejskal-Tanner gradients on a 3T Siemens Verio, a 3T Siemens Connectome Skyra or a 7T Siemens Magnetome scanner) and that a higher order model performs significantly better. The method is already in extensive practical use and is used by four major projects (the WU-UMinn HCP, the MGH HCP, the UK Biobank and the Whitehall studies) to correct for distortions and subject movement.
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217
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Lange T, Maclaren J, Herbst M, Lovell-Smith C, Izadpanah K, Zaitsev M. Knee cartilage MRI with in situ mechanical loading using prospective motion correction. Magn Reson Med 2016; 71:516-23. [PMID: 23440894 DOI: 10.1002/mrm.24679] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
PURPOSE To assess the feasibility of high resolution knee cartilage MRI with in situ mechanical loading using optical tracking to compensate for motion. METHODS In vivo cartilage MRI with in situ mechanical loading is demonstrated on a clinical 3T system for the patellofemoral as well as for the tibiofemoral knee joint using a T1-weighted spoiled three-dimensional gradient-echo sequence. Prospective motion correction is performed with a moiré phase tracking system consisting of an in-bore camera and a single tracking marker attached to the skin. RESULTS Rigid-body approximation required for prospective correction with optical motion tracking is fulfilled well enough for the patellofemoral as well as for the tibiofemoral joint when the tracking marker is attached to the knee cap and the shin, respectively. Presaturation proves to be efficient in suppressing pulsation artifacts from the popliteal artery and residual motion artifacts primarily arising from nonrigid motion of the posterior knee compartment. CONCLUSION The proposed technique enables knee cartilage imaging under in situ mechanical loading with submillimeter spatial resolution devoid of significant motion artifacts and thus appropriate for cartilage volumetry. It has the potential to provide new insight into the biomechanics of the knee and might complement the panoply of diagnostic MR methods for osteoarthritis.
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Affiliation(s)
- Thomas Lange
- Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany
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218
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Waehnert MD, Dinse J, Schäfer A, Geyer S, Bazin PL, Turner R, Tardif CL. A subject-specific framework for in vivo myeloarchitectonic analysis using high resolution quantitative MRI. Neuroimage 2016; 125:94-107. [DOI: 10.1016/j.neuroimage.2015.10.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 09/30/2015] [Accepted: 10/01/2015] [Indexed: 01/22/2023] Open
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219
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Tisdall MD, Reuter M, Qureshi A, Buckner RL, Fischl B, van der Kouwe AJW. Prospective motion correction with volumetric navigators (vNavs) reduces the bias and variance in brain morphometry induced by subject motion. Neuroimage 2015; 127:11-22. [PMID: 26654788 DOI: 10.1016/j.neuroimage.2015.11.054] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 11/20/2015] [Accepted: 11/21/2015] [Indexed: 10/22/2022] Open
Abstract
Recent work has demonstrated that subject motion produces systematic biases in the metrics computed by widely used morphometry software packages, even when the motion is too small to produce noticeable image artifacts. In the common situation where the control population exhibits different behaviors in the scanner when compared to the experimental population, these systematic measurement biases may produce significant confounds for between-group analyses, leading to erroneous conclusions about group differences. While previous work has shown that prospective motion correction can improve perceived image quality, here we demonstrate that, in healthy subjects performing a variety of directed motions, the use of the volumetric navigator (vNav) prospective motion correction system significantly reduces the motion-induced bias and variance in morphometry.
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Affiliation(s)
- M Dylan Tisdall
- Athinoula A. Martinos Center for Biomedical Research, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA; Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
| | - Martin Reuter
- Athinoula A. Martinos Center for Biomedical Research, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA; Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA; Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Abid Qureshi
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Randy L Buckner
- Athinoula A. Martinos Center for Biomedical Research, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA; Center for Brain Science, Harvard University, Cambridge, MA 02138, USA; Department of Psychology, Harvard University, Cambridge, MA 02138, USA; Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Bruce Fischl
- Athinoula A. Martinos Center for Biomedical Research, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA; Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA; Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - André J W van der Kouwe
- Athinoula A. Martinos Center for Biomedical Research, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA; Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
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220
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Li Y, Wang H, Tkach J, Roach D, Woods J, Dumoulin C. Wavelet-space correlation imaging for high-speed MRI without motion monitoring or data segmentation. Magn Reson Med 2015; 74:1574-86. [PMID: 25470230 PMCID: PMC4452472 DOI: 10.1002/mrm.25546] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 10/12/2014] [Accepted: 11/03/2014] [Indexed: 11/11/2022]
Abstract
PURPOSE This study aims to (i) develop a new high-speed MRI approach by implementing correlation imaging in wavelet-space, and (ii) demonstrate the ability of wavelet-space correlation imaging to image human anatomy with involuntary or physiological motion. METHODS Correlation imaging is a high-speed MRI framework in which image reconstruction relies on quantification of data correlation. The presented work integrates correlation imaging with a wavelet transform technique developed originally in the field of signal and image processing. This provides a new high-speed MRI approach to motion-free data collection without motion monitoring or data segmentation. The new approach, called "wavelet-space correlation imaging", is investigated in brain imaging with involuntary motion and chest imaging with free-breathing. RESULTS Wavelet-space correlation imaging can exceed the speed limit of conventional parallel imaging methods. Using this approach with high acceleration factors (6 for brain MRI, 16 for cardiac MRI, and 8 for lung MRI), motion-free images can be generated in static brain MRI with involuntary motion and nonsegmented dynamic cardiac/lung MRI with free-breathing. CONCLUSION Wavelet-space correlation imaging enables high-speed MRI in the presence of involuntary motion or physiological dynamics without motion monitoring or data segmentation.
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Affiliation(s)
- Yu Li
- Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Hui Wang
- Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Jean Tkach
- Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - David Roach
- Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Jason Woods
- Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Charles Dumoulin
- Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
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221
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Jaeger L, Marchal-Crespo L, Wolf P, Riener R, Kollias S, Michels L. Test-retest reliability of fMRI experiments during robot-assisted active and passive stepping. J Neuroeng Rehabil 2015. [PMID: 26577598 DOI: 10.1186/s12984‐015‐0097‐2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Brain activity has been shown to undergo cortical and sub-cortical functional reorganisation over the course of gait rehabilitation in patients suffering from a spinal cord injury or a stroke. These changes however, have not been completely elucidated by neuroimaging to date, mainly due to the scarcity of long-term, follow-up investigations. The magnetic resonance imaging (MRI) compatible stepper MARCOS was specifically developed to enable the investigation of the supraspinal adaptations in paretic patients undergoing gait-rehabilitation in a controlled and repeatable manner. In view of future clinical research, the present study aims at examining the test-retest reliability of functional MRI (fMRI) experiments using MARCOS. METHODS The effect of repeated active and passive stepping movements on brain activity was investigated in 16 healthy participants from fMRI data collected in two separate imaging sessions six weeks apart. Root mean square errors (RMSE) were calculated for the metrics of motor performance. Regional overlap of brain activation between sessions, as well as an intra-class correlation coefficient (ICC) was computed from the single-subject and group activation maps for five regions of interest (ROI). RESULTS Data from eight participants had to be excluded due to excessive head motion. Reliability of motor performance was higher during passive than active movements, as seen in 4.5- to 13-fold lower RMSE for passive movements. In contrast, ICC ranged from 0.48 to 0.72 during passive movements and from 0.77 to 0.85 during active movements. Regional overlap of activations was also higher during active than during passive movements. CONCLUSION These findings imply that an increased variability of motor performance during active movements of healthy participants may be associated with a stable neuronal activation pattern across repeated measurements. In contrast, a stable motor performance during passive movements may be accompanied by a confined reliability of brain activation across repeated measurements.
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Affiliation(s)
- Lukas Jaeger
- Department of Health Sciences and Technology, Sensory-Motor Systems (SMS) Lab, ETH Zurich, ML G 59, Sonneggstrasse 3, 8092, Zurich, Switzerland. .,Medical Faculty, University of Zurich, Zurich, Switzerland. .,Clinic of Neuroradiology, University Hospital of Zurich, Zurich, Switzerland.
| | - Laura Marchal-Crespo
- Department of Health Sciences and Technology, Sensory-Motor Systems (SMS) Lab, ETH Zurich, ML G 59, Sonneggstrasse 3, 8092, Zurich, Switzerland. .,Medical Faculty, University of Zurich, Zurich, Switzerland.
| | - Peter Wolf
- Department of Health Sciences and Technology, Sensory-Motor Systems (SMS) Lab, ETH Zurich, ML G 59, Sonneggstrasse 3, 8092, Zurich, Switzerland. .,Medical Faculty, University of Zurich, Zurich, Switzerland.
| | - Robert Riener
- Department of Health Sciences and Technology, Sensory-Motor Systems (SMS) Lab, ETH Zurich, ML G 59, Sonneggstrasse 3, 8092, Zurich, Switzerland. .,Medical Faculty, University of Zurich, Zurich, Switzerland.
| | - Spyros Kollias
- Clinic of Neuroradiology, University Hospital of Zurich, Zurich, Switzerland.
| | - Lars Michels
- Clinic of Neuroradiology, University Hospital of Zurich, Zurich, Switzerland. .,Center of MR-Research, University Children's Hospital, Zurich, Switzerland.
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Jaeger L, Marchal-Crespo L, Wolf P, Riener R, Kollias S, Michels L. Test-retest reliability of fMRI experiments during robot-assisted active and passive stepping. J Neuroeng Rehabil 2015; 12:102. [PMID: 26577598 PMCID: PMC4647500 DOI: 10.1186/s12984-015-0097-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 11/06/2015] [Indexed: 11/10/2022] Open
Abstract
Background Brain activity has been shown to undergo cortical and sub-cortical functional reorganisation over the course of gait rehabilitation in patients suffering from a spinal cord injury or a stroke. These changes however, have not been completely elucidated by neuroimaging to date, mainly due to the scarcity of long-term, follow-up investigations. The magnetic resonance imaging (MRI) compatible stepper MARCOS was specifically developed to enable the investigation of the supraspinal adaptations in paretic patients undergoing gait-rehabilitation in a controlled and repeatable manner. In view of future clinical research, the present study aims at examining the test-retest reliability of functional MRI (fMRI) experiments using MARCOS. Methods The effect of repeated active and passive stepping movements on brain activity was investigated in 16 healthy participants from fMRI data collected in two separate imaging sessions six weeks apart. Root mean square errors (RMSE) were calculated for the metrics of motor performance. Regional overlap of brain activation between sessions, as well as an intra-class correlation coefficient (ICC) was computed from the single-subject and group activation maps for five regions of interest (ROI). Results Data from eight participants had to be excluded due to excessive head motion. Reliability of motor performance was higher during passive than active movements, as seen in 4.5- to 13-fold lower RMSE for passive movements. In contrast, ICC ranged from 0.48 to 0.72 during passive movements and from 0.77 to 0.85 during active movements. Regional overlap of activations was also higher during active than during passive movements. Conclusion These findings imply that an increased variability of motor performance during active movements of healthy participants may be associated with a stable neuronal activation pattern across repeated measurements. In contrast, a stable motor performance during passive movements may be accompanied by a confined reliability of brain activation across repeated measurements.
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Affiliation(s)
- Lukas Jaeger
- Department of Health Sciences and Technology, Sensory-Motor Systems (SMS) Lab, ETH Zurich, ML G 59, Sonneggstrasse 3, 8092, Zurich, Switzerland. .,Medical Faculty, University of Zurich, Zurich, Switzerland. .,Clinic of Neuroradiology, University Hospital of Zurich, Zurich, Switzerland.
| | - Laura Marchal-Crespo
- Department of Health Sciences and Technology, Sensory-Motor Systems (SMS) Lab, ETH Zurich, ML G 59, Sonneggstrasse 3, 8092, Zurich, Switzerland. .,Medical Faculty, University of Zurich, Zurich, Switzerland.
| | - Peter Wolf
- Department of Health Sciences and Technology, Sensory-Motor Systems (SMS) Lab, ETH Zurich, ML G 59, Sonneggstrasse 3, 8092, Zurich, Switzerland. .,Medical Faculty, University of Zurich, Zurich, Switzerland.
| | - Robert Riener
- Department of Health Sciences and Technology, Sensory-Motor Systems (SMS) Lab, ETH Zurich, ML G 59, Sonneggstrasse 3, 8092, Zurich, Switzerland. .,Medical Faculty, University of Zurich, Zurich, Switzerland.
| | - Spyros Kollias
- Clinic of Neuroradiology, University Hospital of Zurich, Zurich, Switzerland.
| | - Lars Michels
- Clinic of Neuroradiology, University Hospital of Zurich, Zurich, Switzerland. .,Center of MR-Research, University Children's Hospital, Zurich, Switzerland.
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223
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Nofiele J, Yuan Q, Kazem M, Tatebe K, Torres Q, Sawant A, Pedrosa I, Chopra R. An MRI-compatible platform for one-dimensional motion management studies in MRI. Magn Reson Med 2015; 76:702-12. [PMID: 26493684 DOI: 10.1002/mrm.25903] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 07/17/2015] [Accepted: 07/30/2015] [Indexed: 01/17/2023]
Abstract
PURPOSE Abdominal MRI remains challenging because of respiratory motion. Motion compensation strategies are difficult to compare clinically because of the variability across human subjects. The goal of this study was to evaluate a programmable system for one-dimensional motion management MRI research. METHODS A system comprised of a programmable motorized linear stage and computer was assembled and tested in the MRI environment. Tests of the mutual interference between the platform and a whole-body MRI were performed. Organ trajectories generated from a high-temporal resolution scan of a healthy volunteer were used in phantom tests to evaluate the effects of motion on image quality and quantitative MRI measurements. RESULTS No interference between the motion platform and the MRI was observed, and reliable motion could be produced across a wide range of imaging conditions. Motion-related artifacts commensurate with motion amplitude, frequency, and waveform were observed. T2 measurement of a kidney lesion in an abdominal phantom showed that its value decreased by 67% with physiologic motion, but could be partially recovered with navigator-based motion-compensation. CONCLUSION The motion platform can produce reliable linear motion within a whole-body MRI. The system can serve as a foundation for a research platform to investigate and develop motion management approaches for MRI. Magn Reson Med 76:702-712, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Joris Nofiele
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Qing Yuan
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | | | - Ken Tatebe
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Quinn Torres
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Amit Sawant
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Ivan Pedrosa
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Rajiv Chopra
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Sunnybrook Research Institute, Toronto, Ontario, Canada.,Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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224
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Allievi AG, Arichi T, Tusor N, Kimpton J, Arulkumaran S, Counsell SJ, Edwards AD, Burdet E. Maturation of Sensori-Motor Functional Responses in the Preterm Brain. Cereb Cortex 2015; 26:402-413. [PMID: 26491066 PMCID: PMC4677983 DOI: 10.1093/cercor/bhv203] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Preterm birth engenders an increased risk of conditions like cerebral palsy and therefore this time may be crucial for the brain's developing sensori-motor system. However, little is known about how cortical sensori-motor function matures at this time, whether development is influenced by experience, and about its role in spontaneous motor behavior. We aimed to systematically characterize spatial and temporal maturation of sensori-motor functional brain activity across this period using functional MRI and a custom-made robotic stimulation device. We studied 57 infants aged from 30 + 2 to 43 + 2 weeks postmenstrual age. Following both induced and spontaneous right wrist movements, we saw consistent positive blood oxygen level–dependent functional responses in the contralateral (left) primary somatosensory and motor cortices. In addition, we saw a maturational trend toward faster, higher amplitude, and more spatially dispersed functional responses; and increasing integration of the ipsilateral hemisphere and sensori-motor associative areas. We also found that interhemispheric functional connectivity was significantly related to ex-utero exposure, suggesting the influence of experience-dependent mechanisms. At term equivalent age, we saw a decrease in both response amplitude and interhemispheric functional connectivity, and an increase in spatial specificity, culminating in the establishment of a sensori-motor functional response similar to that seen in adults.
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Affiliation(s)
| | - Tomoki Arichi
- Department of Bioengineering.,Centre for the Developing Brain, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St Thomas' Hospital, London SE1 7EH, UK
| | - Nora Tusor
- Centre for the Developing Brain, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St Thomas' Hospital, LondonSE1 7EH, UK
| | - Jessica Kimpton
- Centre for the Developing Brain, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St Thomas' Hospital, LondonSE1 7EH, UK
| | - Sophie Arulkumaran
- Centre for the Developing Brain, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St Thomas' Hospital, LondonSE1 7EH, UK
| | - Serena J Counsell
- Centre for the Developing Brain, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St Thomas' Hospital, LondonSE1 7EH, UK
| | - A David Edwards
- Department of Bioengineering.,Division of Brain Sciences, Department of Medicine, Imperial College of Science, Technology and Medicine, London SW7 2AZ, UK.,Centre for the Developing Brain, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St Thomas' Hospital, London SE1 7EH, UK
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225
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Patriat R, Molloy EK, Birn RM. Using Edge Voxel Information to Improve Motion Regression for rs-fMRI Connectivity Studies. Brain Connect 2015; 5:582-95. [PMID: 26107049 DOI: 10.1089/brain.2014.0321] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Recent fMRI studies have outlined the critical impact of in-scanner head motion, particularly on estimates of functional connectivity. Common strategies to reduce the influence of motion include realignment as well as the inclusion of nuisance regressors, such as the 6 realignment parameters, their first derivatives, time-shifted versions of the realignment parameters, and the squared parameters. However, these regressors have limited success at noise reduction. We hypothesized that using nuisance regressors consisting of the principal components (PCs) of edge voxel time series would be better able to capture slice-specific and nonlinear signal changes, thus explaining more variance, improving data quality (i.e., lower DVARS and temporal SNR), and reducing the effect of motion on default-mode network connectivity. Functional MRI data from 22 healthy adult subjects were preprocessed using typical motion regression approaches as well as nuisance regression derived from edge voxel time courses. Results were evaluated in the presence and absence of both global signal regression and motion censoring. Nuisance regressors derived from signal intensity time courses at the edge of the brain significantly improved motion correction compared to using only the realignment parameters and their derivatives. Of the models tested, only the edge voxel regression models were able to eliminate significant differences in default-mode network connectivity between high- and low-motion subjects regardless of the use of global signal regression or censoring.
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Affiliation(s)
- Rémi Patriat
- 1 Department of Medical Physics, University of Wisconsin-Madison , Madison, Wisconsin
| | - Erin K Molloy
- 2 Department of Psychiatry, University of Wisconsin-Madison , Madison, Wisconsin.,3 Department of Computer Science, University of Illinois-Urbana-Champaign , Urbana, Illinois
| | - Rasmus M Birn
- 1 Department of Medical Physics, University of Wisconsin-Madison , Madison, Wisconsin.,2 Department of Psychiatry, University of Wisconsin-Madison , Madison, Wisconsin
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226
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Chen JE, Glover GH. Functional Magnetic Resonance Imaging Methods. Neuropsychol Rev 2015; 25:289-313. [PMID: 26248581 PMCID: PMC4565730 DOI: 10.1007/s11065-015-9294-9] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Accepted: 07/28/2015] [Indexed: 12/11/2022]
Abstract
Since its inception in 1992, Functional Magnetic Resonance Imaging (fMRI) has become an indispensible tool for studying cognition in both the healthy and dysfunctional brain. FMRI monitors changes in the oxygenation of brain tissue resulting from altered metabolism consequent to a task-based evoked neural response or from spontaneous fluctuations in neural activity in the absence of conscious mentation (the "resting state"). Task-based studies have revealed neural correlates of a large number of important cognitive processes, while fMRI studies performed in the resting state have demonstrated brain-wide networks that result from brain regions with synchronized, apparently spontaneous activity. In this article, we review the methods used to acquire and analyze fMRI signals.
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Affiliation(s)
- Jingyuan E Chen
- Department of Radiology, Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA,
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227
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Abstract
High field MRI systems, such as 7 Tesla (T) scanners, can deliver higher signal to noise ratio (SNR) than lower field scanners and thus allow for the acquisition of data with higher spatial resolution, which is often demanded by users in the fields of clinical and neuroscientific imaging. However, high resolution scans may require long acquisition times, which in turn increase the discomfort for the subject and the risk of subject motion. Even with a cooperative and trained subject, involuntary motion due to heartbeat, swallowing, respiration and changes in muscle tone can cause image artifacts that reduce the effective resolution. In addition, scanning with higher resolution leads to increased sensitivity to even very small movements. Prospective motion correction (PMC) at 3T and 7T has proven to increase image quality in case of subject motion. Although the application of prospective motion correction is becoming more popular, previous articles focused on proof of concept studies and technical descriptions, whereas this paper briefly describes the technical aspects of the optical tracking system, marker fixation and cross calibration and focuses on the application of PMC to very high resolution imaging without intentional motion. In this study we acquired in vivo MR images at 7T using prospective motion correction during long acquisitions. As a result, we present images among the highest, if not the highest resolution of in vivo human brain MRI ever acquired.
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228
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Optical tracking with two markers for robust prospective motion correction for brain imaging. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2015; 28:523-34. [PMID: 26121941 DOI: 10.1007/s10334-015-0493-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 06/10/2015] [Accepted: 06/11/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVE Prospective motion correction (PMC) during brain imaging using camera-based tracking of a skin-attached marker may suffer from problems including loss of marker visibility due to the coil and false correction due to non-rigid-body facial motion, such as frowning or squinting. A modified PMC system is introduced to mitigate these problems and increase the robustness of motion correction. MATERIALS AND METHODS The method relies on simultaneously tracking two markers, each providing six degrees of freedom, that are placed on the forehead. This allows us to track head motion when one marker is obscured and detect skin movements to prevent false corrections. Experiments were performed to compare the performance of the two-marker motion correction technique to the previous single-marker approach. RESULTS Experiments validate the theory developed for adaptive marker tracking and skin movement detection, and demonstrate improved image quality during obstruction of the line-of-sight of one marker when subjects squint or when subjects squint and move simultaneously. CONCLUSION The proposed methods eliminate two common failure modes of PMC and substantially improve the robustness of PMC, and they can be applied to other optical tracking systems capable of tracking multiple markers. The methods presented can be adapted to the use of more than two markers.
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Engström M, Mårtensson M, Avventi E, Norbeck O, Skare S. Collapsed fat navigators for brain 3D rigid body motion. Magn Reson Imaging 2015; 33:984-91. [PMID: 26117701 DOI: 10.1016/j.mri.2015.06.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 05/25/2015] [Accepted: 06/20/2015] [Indexed: 10/23/2022]
Abstract
PURPOSE To acquire high-resolution 3D multi-slab echo planar imaging data without motion artifacts, using collapsed fat navigators. METHODS A fat navigator module (collapsed FatNav) was added to a diffusion-weighted 3D multi-slab echo planar imaging (DW 3D-MS EPI) sequence, comprising three orthogonal echo planar imaging readouts to track rigid body head motion in the image domain and performing prospective motion correction. The stability, resolution and accuracy of the navigator were investigated on phantoms and healthy volunteers. RESULTS The experiments on phantoms and volunteers show that the navigator, depicting projections of the subcutaneous fat in of the head, is capable of correcting for head motion with insignificant bias compared to motion estimates derived from the water-signaling DWI images. Despite that this projection technique implies a non-sparse image appearance, collapsed FatNav data could be highly accelerated with parallel imaging, allowing three orthogonal 2D EPI readouts in about 6ms. CONCLUSION By utilizing signal from the leading fat saturation RF pulse of the diffusion sequence, only the readout portion of the navigator needs to be added, resulting in a scan time penalty of only about 5%. Motion can be detected and corrected for with a 5-10Hz update frequency when combined with a sequence like the DW 3D-MS EPI.
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Affiliation(s)
- Mathias Engström
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden; EMEA Research and Collaboration, GE Applies Science Laboratory, GE Healthcare, Stockholm, Sweden.
| | - Magnus Mårtensson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden; EMEA Research and Collaboration, GE Applies Science Laboratory, GE Healthcare, Stockholm, Sweden
| | - Enrico Avventi
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden; EMEA Research and Collaboration, GE Applies Science Laboratory, GE Healthcare, Stockholm, Sweden
| | - Ola Norbeck
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden; EMEA Research and Collaboration, GE Applies Science Laboratory, GE Healthcare, Stockholm, Sweden
| | - Stefan Skare
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden; EMEA Research and Collaboration, GE Applies Science Laboratory, GE Healthcare, Stockholm, Sweden
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230
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Herrmann T, Mallow J, Plaumann M, Luchtmann M, Stadler J, Mylius J, Brosch M, Bernarding J. The Travelling-Wave Primate System: A New Solution for Magnetic Resonance Imaging of Macaque Monkeys at 7 Tesla Ultra-High Field. PLoS One 2015; 10:e0129371. [PMID: 26066653 PMCID: PMC4466239 DOI: 10.1371/journal.pone.0129371] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 05/07/2015] [Indexed: 02/05/2023] Open
Abstract
Introduction Neuroimaging of macaques at ultra-high field (UHF) is usually conducted by combining a volume coil for transmit (Tx) and a phased array coil for receive (Rx) tightly enclosing the monkey’s head. Good results have been achieved using vertical or horizontal magnets with implanted or near-surface coils. An alternative and less costly approach, the travelling-wave (TW) excitation concept, may offer more flexible experimental setups on human whole-body UHF magnetic resonance imaging (MRI) systems, which are now more widely available. Goal of the study was developing and validating the TW concept for in vivo primate MRI. Methods The TW Primate System (TWPS) uses the radio frequency shield of the gradient system of a human whole-body 7 T MRI system as a waveguide to propagate a circularly polarized B1 field represented by the TE11 mode. This mode is excited by a specifically designed 2-port patch antenna. For receive, a customized neuroimaging monkey head receive-only coil was designed. Field simulation was used for development and evaluation. Signal-to-noise ratio (SNR) was compared with data acquired with a conventional monkey volume head coil consisting of a homogeneous transmit coil and a 12-element receive coil. Results The TWPS offered good image homogeneity in the volume-of-interest Turbo spin echo images exhibited a high contrast, allowing a clear depiction of the cerebral anatomy. As a prerequisite for functional MRI, whole brain ultrafast echo planar images were successfully acquired. Conclusion The TWPS presents a promising new approach to fMRI of macaques for research groups with access to a horizontal UHF MRI system.
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Affiliation(s)
- Tim Herrmann
- Department of Biometrics and Medical Informatics, OvG University, Magdeburg, Germany
- * E-mail:
| | - Johannes Mallow
- Department of Biometrics and Medical Informatics, OvG University, Magdeburg, Germany
| | - Markus Plaumann
- Department of Biometrics and Medical Informatics, OvG University, Magdeburg, Germany
| | - Michael Luchtmann
- Department of Biometrics and Medical Informatics, OvG University, Magdeburg, Germany
| | - Jörg Stadler
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany
| | - Judith Mylius
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany
| | - Michael Brosch
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany
- Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Johannes Bernarding
- Department of Biometrics and Medical Informatics, OvG University, Magdeburg, Germany
- Center for Behavioral Brain Sciences, Magdeburg, Germany
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231
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Kreilkamp BA, Zacà D, Papinutto N, Jovicich J. Retrospective head motion correction approaches for diffusion tensor imaging: Effects of preprocessing choices on biases and reproducibility of scalar diffusion metrics. J Magn Reson Imaging 2015; 43:99-106. [DOI: 10.1002/jmri.24965] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 05/20/2015] [Indexed: 11/07/2022] Open
Affiliation(s)
- Barbara A.K. Kreilkamp
- Center for Mind/Brain Sciences (CIMEC), University of Trento; Rovereto Italy
- Institute of Translational Medicine; University of Liverpool; Liverpool UK
| | - Domenico Zacà
- Center for Mind/Brain Sciences (CIMEC), University of Trento; Rovereto Italy
| | - Nico Papinutto
- Department of Neurology; University of California San Francisco; San Francisco California USA
| | - Jorge Jovicich
- Center for Mind/Brain Sciences (CIMEC), University of Trento; Rovereto Italy
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232
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Maclaren J, Aksoy M, Bammer R. Contact-free physiological monitoring using a markerless optical system. Magn Reson Med 2015; 74:571-7. [PMID: 25982242 DOI: 10.1002/mrm.25781] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 04/07/2015] [Accepted: 04/29/2015] [Indexed: 11/07/2022]
Abstract
PURPOSE Physiological noise remains a major problem in MRI, particularly at higher imaging resolutions and field strengths. The aim of this work was to investigate the feasibility of using an MR-compatible in-bore camera system to perform contactless monitoring of cardiac and respiratory information during MRI of human subjects. METHODS An MR-compatible camera was mounted on an eight-channel head coil. Video data of the skin was processed offline to derive cardiac and respiratory signals from the pixel signal intensity and from head motion in the patient head-feet direction. These signals were then compared with data acquired simultaneously from the pulse oximeter and the respiratory belt. RESULTS The cardiac signal computed using the average image pixel intensity closely resembled the signal obtained using the pulse oximeter. Trigger intervals obtained from both systems matched to within 50 ms (one standard deviation). The respiratory signal computed from small in-plane movements closely matched the signal obtained from the respiratory belt. Simultaneous MR imaging did not appear to have an effect on the physiological signals acquired by means of the contact-free monitoring system. CONCLUSION Contact-free monitoring of human subjects to obtain cardiac and respiratory information is feasible using a small camera and light emitting diode mounted on the head coil of an MRI scanner.
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Affiliation(s)
- Julian Maclaren
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Murat Aksoy
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Roland Bammer
- Department of Radiology, Stanford University, Stanford, California, USA
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233
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Abstract
In blood-oxygenation-level-dependent functional magnetic resonance imaging (fMRI), current methods typically acquire ∼ 500,000 imaging voxels at each time point, and then use computer algorithms to reduce this data to the coefficients of a few hundred parcels or networks. This suggests that the amount of relevant information present in the fMRI signal is relatively small, and presents an opportunity to greatly improve the speed and signal to noise ratio (SNR) of the fMRI process. In this work, a theoretical framework is presented for calculating the coefficients of functional networks directly from highly undersampled fMRI data. Using predefined functional parcellations or networks and a compact k-space trajectory that samples data at optimal spatial scales, the problem of estimating network coefficients is reformulated to allow for direct least squares estimation, without Fourier encoding. By simulation, this approach is shown to allow for acceleration of the imaging process under ideal circumstances by nearly three orders of magnitude.
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Affiliation(s)
- Eric C Wong
- Departments of Radiology and Psychiatry, University of California , San Diego, La Jolla, California
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234
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Andre JB, Bresnahan BW, Mossa-Basha M, Hoff MN, Smith CP, Anzai Y, Cohen WA. Toward Quantifying the Prevalence, Severity, and Cost Associated With Patient Motion During Clinical MR Examinations. J Am Coll Radiol 2015; 12:689-95. [PMID: 25963225 DOI: 10.1016/j.jacr.2015.03.007] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 03/04/2015] [Indexed: 11/19/2022]
Abstract
PURPOSE To assess the prevalence, severity, and cost estimates associated with motion artifacts identified on clinical MR examinations, with a focus on the neuroaxis. METHODS A retrospective review of 1 randomly selected full calendar week of MR examinations (April 2014) was conducted for the detection of significant motion artifacts in examinations performed at a single institution on 3 different MR scanners. A base-case cost estimate was computed from recently available institutional data, and correlated with sequence time and severity of motion artifacts. RESULTS A total of 192 completed clinical examinations were reviewed. Significant motion artifacts were identified on sequences in 7.5% of outpatient and 29.4% of inpatient and/or emergency department MR examinations. The prevalence of repeat sequences was 19.8% of total MRI examinations. The base-case cost estimate yielded a potential cost to the hospital of $592 per hour in lost revenue due to motion artifacts. Potential institutional average costs borne (revenue forgone) of approximately $115,000 per scanner per year may affect hospitals, owing to motion artifacts (univariate sensitivity analysis suggested a lower bound of $92,600, and an upper bound of $139,000). CONCLUSIONS Motion artifacts represent a frequent cause of MR image degradation, particularly for inpatient and emergency department patients, resulting in substantial costs to the radiology department. Greater attention and resources should be directed toward providing practical solutions to this dilemma.
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Affiliation(s)
- Jalal B Andre
- Department of Radiology, University of Washington, Seattle, Washington.
| | - Brian W Bresnahan
- Department of Radiology, University of Washington, Seattle, Washington
| | | | - Michael N Hoff
- Department of Radiology, University of Washington, Seattle, Washington
| | - C Patrick Smith
- Department of Radiology, Harborview Medical Center, Seattle, Washington
| | - Yoshimi Anzai
- Department of Radiology, University of Washington, Seattle, Washington
| | - Wendy A Cohen
- Department of Radiology, University of Washington, Seattle, Washington
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235
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Callaghan MF, Josephs O, Herbst M, Zaitsev M, Todd N, Weiskopf N. An evaluation of prospective motion correction (PMC) for high resolution quantitative MRI. Front Neurosci 2015; 9:97. [PMID: 25859178 PMCID: PMC4373264 DOI: 10.3389/fnins.2015.00097] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 03/06/2015] [Indexed: 01/06/2023] Open
Abstract
Quantitative imaging aims to provide in vivo neuroimaging biomarkers with high research and diagnostic value that are sensitive to underlying tissue microstructure. In order to use these data to examine intra-cortical differences or to define boundaries between different myelo-architectural areas, high resolution data are required. The quality of such measurements is degraded in the presence of motion hindering insight into brain microstructure. Correction schemes are therefore vital for high resolution, whole brain coverage approaches that have long acquisition times and greater sensitivity to motion. Here we evaluate the use of prospective motion correction (PMC) via an optical tracking system to counter intra-scan motion in a high resolution (800 μm isotropic) multi-parameter mapping (MPM) protocol. Data were acquired on six volunteers using a 2 × 2 factorial design permuting the following conditions: PMC on/off and motion/no motion. In the presence of head motion, PMC-based motion correction considerably improved the quality of the maps as reflected by fewer visible artifacts and improved consistency. The precision of the maps, parameterized through the coefficient of variation in cortical sub-regions, showed improvements of 11-25% in the presence of deliberate head motion. Importantly, in the absence of motion the PMC system did not introduce extraneous artifacts into the quantitative maps. The PMC system based on optical tracking offers a robust approach to minimizing motion artifacts in quantitative anatomical imaging without extending scan times. Such a robust motion correction scheme is crucial in order to achieve the ultra-high resolution required of quantitative imaging for cutting edge in vivo histology applications.
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Affiliation(s)
- Martina F. Callaghan
- Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College LondonLondon, UK
| | - Oliver Josephs
- Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College LondonLondon, UK
| | - Michael Herbst
- Department of Radiology, University Medical Centre FreiburgFreiburg, Germany
- Department of Medicine, John A. Burns School of MedicineHawaii, HI, USA
| | - Maxim Zaitsev
- Department of Radiology, University Medical Centre FreiburgFreiburg, Germany
| | - Nick Todd
- Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College LondonLondon, UK
| | - Nikolaus Weiskopf
- Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College LondonLondon, UK
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236
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Todd N, Josephs O, Callaghan MF, Lutti A, Weiskopf N. Prospective motion correction of 3D echo-planar imaging data for functional MRI using optical tracking. Neuroimage 2015; 113:1-12. [PMID: 25783205 PMCID: PMC4441089 DOI: 10.1016/j.neuroimage.2015.03.013] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 02/09/2015] [Accepted: 03/08/2015] [Indexed: 12/04/2022] Open
Abstract
We evaluated the performance of an optical camera based prospective motion correction (PMC) system in improving the quality of 3D echo-planar imaging functional MRI data. An optical camera and external marker were used to dynamically track the head movement of subjects during fMRI scanning. PMC was performed by using the motion information to dynamically update the sequence's RF excitation and gradient waveforms such that the field-of-view was realigned to match the subject's head movement. Task-free fMRI experiments on five healthy volunteers followed a 2 × 2 × 3 factorial design with the following factors: PMC on or off; 3.0 mm or 1.5 mm isotropic resolution; and no, slow, or fast head movements. Visual and motor fMRI experiments were additionally performed on one of the volunteers at 1.5 mm resolution comparing PMC on vs PMC off for no and slow head movements. Metrics were developed to quantify the amount of motion as it occurred relative to k-space data acquisition. The motion quantification metric collapsed the very rich camera tracking data into one scalar value for each image volume that was strongly predictive of motion-induced artifacts. The PMC system did not introduce extraneous artifacts for the no motion conditions and improved the time series temporal signal-to-noise by 30% to 40% for all combinations of low/high resolution and slow/fast head movement relative to the standard acquisition with no prospective correction. The numbers of activated voxels (p < 0.001, uncorrected) in both task-based experiments were comparable for the no motion cases and increased by 78% and 330%, respectively, for PMC on versus PMC off in the slow motion cases. The PMC system is a robust solution to decrease the motion sensitivity of multi-shot 3D EPI sequences and thereby overcome one of the main roadblocks to their widespread use in fMRI studies. Data quality was assessed in terms of tSNR, RMSE, and task fMRI t-statistics. Correction improved tSNR by 30% to 40%. Percent reduction in RMSE as a function of motion level was characterized. Number of active voxels for motor and visual tasks increased significantly.
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Affiliation(s)
- Nick Todd
- Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College London, London, UK.
| | - Oliver Josephs
- Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College London, London, UK
| | - Martina F Callaghan
- Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College London, London, UK
| | - Antoine Lutti
- Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College London, London, UK; Laboratoire de Recherche en Neuroimagerie, Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Nikolaus Weiskopf
- Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College London, London, UK
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237
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Pannetier NA, Stavrinos T, Ng P, Herbst M, Zaitsev M, Young K, Matson G, Schuff N. Quantitative framework for prospective motion correction evaluation. Magn Reson Med 2015; 75:810-6. [PMID: 25761550 DOI: 10.1002/mrm.25580] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 11/18/2014] [Accepted: 11/24/2014] [Indexed: 10/23/2022]
Abstract
PURPOSE Establishing a framework to evaluate performances of prospective motion correction (PMC) MRI considering motion variability between MRI scans. METHODS A framework was developed to obtain quantitative comparisons between different motion correction setups, considering that varying intrinsic motion patterns between acquisitions can induce bias. Intrinsic motion was considered by replaying in a phantom experiment the recorded motion trajectories from subjects. T1-weighted MRI on five volunteers and two different marker fixations (mouth guard and nose bridge fixations) were used to test the framework. Two metrics were investigated to quantify the improvement of the image quality with PMC. RESULTS Motion patterns vary between subjects as well as between repeated scans within a subject. This variability can be approximated by replaying the motion in a distinct phantom experiment and used as a covariate in models comparing motion corrections. We show that considering the intrinsic motion alters the statistical significance in comparing marker fixations. As an example, two marker fixations, a mouth guard and a nose bridge, were evaluated in terms of their effectiveness for PMC. A mouth guard achieved better PMC performance. CONCLUSION Intrinsic motion patterns can bias comparisons between PMC configurations and must be considered for robust evaluations. A framework for evaluating intrinsic motion patterns in PMC is presented.
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Affiliation(s)
- Nicolas A Pannetier
- Center for Imaging of Neurodegenerative Diseases, Veteran Affairs Medical Center, San Francisco, California, USA.,Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
| | - Theano Stavrinos
- Center for Imaging of Neurodegenerative Diseases, Veteran Affairs Medical Center, San Francisco, California, USA.,Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
| | - Peter Ng
- Center for Imaging of Neurodegenerative Diseases, Veteran Affairs Medical Center, San Francisco, California, USA.,Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
| | - Michael Herbst
- Department of Radiology, University Medical Center Freiburg, Freiburg, Germany.,Department of Radiology, JABSOM, Honolulu, Hawaii, USA
| | - Maxim Zaitsev
- Department of Radiology, University Medical Center Freiburg, Freiburg, Germany
| | - Karl Young
- Center for Imaging of Neurodegenerative Diseases, Veteran Affairs Medical Center, San Francisco, California, USA.,Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
| | - Gerald Matson
- Center for Imaging of Neurodegenerative Diseases, Veteran Affairs Medical Center, San Francisco, California, USA.,Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
| | - Norbert Schuff
- Center for Imaging of Neurodegenerative Diseases, Veteran Affairs Medical Center, San Francisco, California, USA.,Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
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238
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Zaitsev M, Maclaren J, Herbst M. Motion artifacts in MRI: A complex problem with many partial solutions. J Magn Reson Imaging 2015; 42:887-901. [PMID: 25630632 DOI: 10.1002/jmri.24850] [Citation(s) in RCA: 356] [Impact Index Per Article: 39.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 12/22/2014] [Indexed: 01/29/2023] Open
Abstract
Subject motion during magnetic resonance imaging (MRI) has been problematic since its introduction as a clinical imaging modality. While sensitivity to particle motion or blood flow can be used to provide useful image contrast, bulk motion presents a considerable problem in the majority of clinical applications. It is one of the most frequent sources of artifacts. Over 30 years of research have produced numerous methods to mitigate or correct for motion artifacts, but no single method can be applied in all imaging situations. Instead, a "toolbox" of methods exists, where each tool is suitable for some tasks, but not for others. This article reviews the origins of motion artifacts and presents current mitigation and correction methods. In some imaging situations, the currently available motion correction tools are highly effective; in other cases, appropriate tools still need to be developed. It seems likely that this multifaceted approach will be what eventually solves the motion sensitivity problem in MRI, rather than a single solution that is effective in all situations. This review places a strong emphasis on explaining the physics behind the occurrence of such artifacts, with the aim of aiding artifact detection and mitigation in particular clinical situations.
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Affiliation(s)
- Maxim Zaitsev
- Department of Radiology, University Medical Centre Freiburg, Freiburg, Germany
| | - Julian Maclaren
- Department of Radiology, University Medical Centre Freiburg, Freiburg, Germany.,Department of Radiology, Stanford University, Stanford, California, USA
| | - Michael Herbst
- Department of Radiology, University Medical Centre Freiburg, Freiburg, Germany.,University of Hawaii, Department of Medicine, John A. Burns School of Medicine, Honolulu, Hawaii, USA
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Dormal G, Lepore F, Harissi-Dagher M, Albouy G, Bertone A, Rossion B, Collignon O. Tracking the evolution of crossmodal plasticity and visual functions before and after sight restoration. J Neurophysiol 2014; 113:1727-42. [PMID: 25520432 DOI: 10.1152/jn.00420.2014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Visual deprivation leads to massive reorganization in both the structure and function of the occipital cortex, raising crucial challenges for sight restoration. We tracked the behavioral, structural, and neurofunctional changes occurring in an early and severely visually impaired patient before and 1.5 and 7 mo after sight restoration with magnetic resonance imaging. Robust presurgical auditory responses were found in occipital cortex despite residual preoperative vision. In primary visual cortex, crossmodal auditory responses overlapped with visual responses and remained elevated even 7 mo after surgery. However, these crossmodal responses decreased in extrastriate occipital regions after surgery, together with improved behavioral vision and with increases in both gray matter density and neural activation in low-level visual regions. Selective responses in high-level visual regions involved in motion and face processing were observable even before surgery and did not evolve after surgery. Taken together, these findings demonstrate that structural and functional reorganization of occipital regions are present in an individual with a long-standing history of severe visual impairment and that such reorganizations can be partially reversed by visual restoration in adulthood.
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Affiliation(s)
- Giulia Dormal
- Centre de Recherche en Neuropsychologie et Cognition (CERNEC), Université de Montréal, Montreal, Quebec, Canada; Institute of Research in Psychology (IPSY), Center for Cognitive and Systems Neuroscience, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Franco Lepore
- Centre de Recherche en Neuropsychologie et Cognition (CERNEC), Université de Montréal, Montreal, Quebec, Canada
| | - Mona Harissi-Dagher
- Department of Ophthalmology, Centre Hospitalier de l'Université de Montréal (CHUM) Notre Dame, Montreal, Quebec, Canada
| | - Geneviève Albouy
- Centre de recherche de l'Institut Universitaire de Gériatrie de l'Université de Montréal (CRIUGM), Montreal, Quebec, Canada
| | - Armando Bertone
- Department of Education and Counselling Psychology, McGill University, Montreal, Quebec, Canada; and
| | - Bruno Rossion
- Institute of Research in Psychology (IPSY), Center for Cognitive and Systems Neuroscience, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Olivier Collignon
- Centre de Recherche en Neuropsychologie et Cognition (CERNEC), Université de Montréal, Montreal, Quebec, Canada; Centro Interdipartimentale Mente/Cervello (CIMeC), Università di Trento, Mattarello, Italy
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240
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Hoffmann M, Carpenter TA, Williams GB, Sawiak SJ. A survey of patient motion in disorders of consciousness and optimization of its retrospective correction. Magn Reson Imaging 2014; 33:346-50. [PMID: 25485789 DOI: 10.1016/j.mri.2014.11.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 10/17/2014] [Accepted: 11/24/2014] [Indexed: 11/29/2022]
Abstract
Functional magnetic resonance imaging (fMRI) can be seriously impaired by patient motion. The purpose of this study was to characterize the typical motion in a clinical population of patients in disorders of consciousness and compare the performance of retrospective correction with rigid-body realignment as implemented in widely used software packages. 63 subjects were scanned with an fMRI visual checkerboard paradigm using a 3T scanner. Time series were corrected for motion, and the resulting transformations were used to calculate a motion score. SPM, FSL, AFNI and AIR were evaluated by comparing the motion obtained by re-running the tool on the corrected data. A publicly available sample fMRI dataset was modified with the motion detected in each patient with each tool. The performance of each tool was measured by comparing the number of supra-threshold voxels after standard fMRI analysis, both in the sample dataset and in simulated fMRI data. We assessed the effect of user-changeable parameters on motion correction in SPM. We found the equivalent motion in the patient population to be 1.4mm on average. There was no significant difference in performance between SPM, FSL and AFNI. AIR was considerably worse, and took more time to run. We found that in SPM the quality factor and interpolation method have no effect on the cluster size, while higher separation and smoothing reduce it. We showed that the main packages SPM, FSL and AFNI are equally suitable for retrospective motion correction of fMRI time series. We show that typically only 80% of activated voxels are recovered by retrospective motion correction.
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Affiliation(s)
- Malte Hoffmann
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom.
| | - T Adrian Carpenter
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom
| | - Guy B Williams
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom
| | - Stephen J Sawiak
- Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom; Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom
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Li G, Zaitsev M, Büchert M, Raithel E, Paul D, Korvink JG, Hennig J. Improving the robustness of 3D turbo spin echo imaging to involuntary motion. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2014; 28:329-45. [DOI: 10.1007/s10334-014-0471-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 10/14/2014] [Accepted: 10/28/2014] [Indexed: 10/24/2022]
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242
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Mossahebi P, Alexander AL, Field AS, Samsonov AA. Removal of cerebrospinal fluid partial volume effects in quantitative magnetization transfer imaging using a three-pool model with nonexchanging water component. Magn Reson Med 2014; 74:1317-26. [PMID: 25394181 DOI: 10.1002/mrm.25516] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 10/01/2014] [Accepted: 10/16/2014] [Indexed: 02/03/2023]
Abstract
PURPOSE Parameters of the two-pool model describing magnetization transfer (MT) in macromolecule-rich tissues may be significantly biased in partial volume (PV) voxels containing cerebrospinal fluid (CSF). The purpose of this study was to develop a quantitative MT (qMT) method that provides indices insensitive to CSF PV averaging. THEORY AND METHODS We propose a three-pool MT model, in which PV macro-compartment is modeled as an additional nonexchanging water pool. We demonstrate the feasibility of model parameter estimation from several MT-weighted spoiled gradient echo datasets. We validated the three-pool model in numerical, phantom, and in vivo studies. RESULTS PV averaging with the free water compartment reduces all qMT parameters, most significantly affecting macromolecular proton fraction (MPF) and cross-relaxation rate. Monte-Carlo simulations confirmed stability of the three-pool model fit. Unlike the standard two-pool model, the three-pool model qMT parameters were not affected by PV averaging in simulations and phantom studies. The three-pool model fit allowed CSF PV correction in brain PV voxels and resulted in good correlation with standard two-pool model parameters in non-PV voxels. CONCLUSION Quantitative MT imaging based on a three-pool model with a non-exchanging water component yields a set of CSF-insensitive qMT parameters, which may improve MPF-based assessment of myelination in structures strongly affected by CSF PV averaging such as brain gray matter.
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Affiliation(s)
- Pouria Mossahebi
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Andrew L Alexander
- Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Aaron S Field
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.,Department of Biomedical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Alexey A Samsonov
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
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243
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Plantinga BR, Temel Y, Roebroeck A, Uludağ K, Ivanov D, Kuijf ML, Ter Haar Romenij BM. Ultra-high field magnetic resonance imaging of the basal ganglia and related structures. Front Hum Neurosci 2014; 8:876. [PMID: 25414656 PMCID: PMC4220687 DOI: 10.3389/fnhum.2014.00876] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 10/10/2014] [Indexed: 12/13/2022] Open
Abstract
Deep brain stimulation is a treatment for Parkinson's disease and other related disorders, involving the surgical placement of electrodes in the deeply situated basal ganglia or thalamic structures. Good clinical outcome requires accurate targeting. However, due to limited visibility of the target structures on routine clinical MR images, direct targeting of structures can be challenging. Non-clinical MR scanners with ultra-high magnetic field (7T or higher) have the potential to improve the quality of these images. This technology report provides an overview of the current possibilities of visualizing deep brain stimulation targets and their related structures with the aid of ultra-high field MRI. Reviewed studies showed improved resolution, contrast- and signal-to-noise ratios at ultra-high field. Sequences sensitive to magnetic susceptibility such as T2* and susceptibility weighted imaging and their maps in general showed the best visualization of target structures, including a separation between the subthalamic nucleus and the substantia nigra, the lamina pallidi medialis and lamina pallidi incompleta within the globus pallidus and substructures of the thalamus, including the ventral intermediate nucleus (Vim). This shows that the visibility, identification, and even subdivision of the small deep brain stimulation targets benefit from increased field strength. Although ultra-high field MR imaging is associated with increased risk of geometrical distortions, it has been shown that these distortions can be avoided or corrected to the extent where the effects are limited. The availability of ultra-high field MR scanners for humans seems to provide opportunities for a more accurate targeting for deep brain stimulation in patients with Parkinson's disease and related disorders.
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Affiliation(s)
- Birgit R Plantinga
- Biomedical Image Analysis, Eindhoven University of Technology Eindhoven, Netherlands ; Department of Neuroscience, Maastricht University Maastricht, Netherlands
| | - Yasin Temel
- Department of Neuroscience, Maastricht University Maastricht, Netherlands ; Department of Neurology, Maastricht University Medical Center Maastricht, Netherlands
| | - Alard Roebroeck
- Department of Neurosurgery, Maastricht University Medical Center Maastricht, Netherlands
| | - Kâmil Uludağ
- Department of Neurosurgery, Maastricht University Medical Center Maastricht, Netherlands
| | - Dimo Ivanov
- Department of Neurosurgery, Maastricht University Medical Center Maastricht, Netherlands
| | - Mark L Kuijf
- Department of Cognitive Neuroscience, Maastricht University Maastricht, Netherlands
| | - Bart M Ter Haar Romenij
- Biomedical Image Analysis, Eindhoven University of Technology Eindhoven, Netherlands ; Department of Biomedical and Information Engineering, Northeastern University Shenyang, China
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244
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Gumus K, Keating B, White N, Andrews-Shigaki B, Armstrong B, Maclaren J, Zaitsev M, Dale A, Ernst T. Comparison of optical and MR-based tracking. Magn Reson Med 2014; 74:894-902. [PMID: 25257096 DOI: 10.1002/mrm.25472] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 08/30/2014] [Accepted: 09/01/2014] [Indexed: 11/09/2022]
Abstract
PURPOSE The goal of this study was to compare the accuracy of two real-time motion tracking systems in the MR environment: MR-based prospective motion correction (PROMO) and optical moiré phase tracking (MPT). METHODS Five subjects performed eight predefined head rotations of 8° ± 3° while being simultaneously tracked with PROMO and MPT. Structural images acquired immediately before and after each tracking experiment were realigned with SPM8 to provide a reference measurement. RESULTS Mean signed errors (MSEs) in MPT tracking relative to SPM8 were less than 0.3 mm and 0.2° in all 6 degrees of freedom, and MSEs in PROMO tracking ranged up to 0.2 mm and 0.3°. MPT and PROMO significantly differed from SPM8 in y-translation and y-rotation values (P < 0.05). Maximum absolute errors ranged up to 2.8 mm and 2.1° for MPT, and 2.2 mm and 2.9° for PROMO. CONCLUSION This study presents the first in vivo comparison of MPT and PROMO tracking. Our data show that two methods yielded similar performances (within 1 mm and 1° standard deviation) relative to reference image registration. Tracking errors of both systems were larger than offline tests. Future work is required for further comparison of two methods in vivo with higher precision.
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Affiliation(s)
- Kazim Gumus
- John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA
| | - Brian Keating
- John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA
| | - Nathan White
- Department of Radiology, University of California, San Diego, La Jolla, California, USA
| | - Brian Andrews-Shigaki
- Department of Military & Emergency Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.,Department of Radiology and Radiological Sciences, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Brian Armstrong
- Department of Electrical Engineering and Computer Science, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA
| | - Julian Maclaren
- Department of Radiology, University Medical Center Freiburg, Freiburg, Germany.,Department of Radiology, Stanford University, Stanford, California, USA
| | - Maxim Zaitsev
- Department of Radiology, University Medical Center Freiburg, Freiburg, Germany
| | - Anders Dale
- Department of Radiology, University of California, San Diego, La Jolla, California, USA
| | - Thomas Ernst
- John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA
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245
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Menys A, Hamy V, Makanyanga J, Hoad C, Gowland P, Odille F, Taylor SA, Atkinson D. Dual registration of abdominal motion for motility assessment in free-breathing data sets acquired using dynamic MRI. Phys Med Biol 2014; 59:4603-19. [PMID: 25079109 DOI: 10.1088/0031-9155/59/16/4603] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
At present, registration-based quantification of bowel motility from dynamic MRI is limited to breath-hold studies. Here we validate a dual-registration technique robust to respiratory motion for the assessment of small bowel and colonic motility. Small bowel datasets were acquired in breath-hold and free-breathing in 20 healthy individuals. A pre-processing step using an iterative registration of the low rank component of the data was applied to remove respiratory motion from the free breathing data. Motility was then quantified with an existing optic-flow (OF) based registration technique to form a dual-stage approach, termed Dual Registration of Abdominal Motion (DRAM). The benefit of respiratory motion correction was assessed by (1) assessing the fidelity of automatically propagated segmental regions of interest (ROIs) in the small bowel and colon and (2) comparing parametric motility maps to a breath-hold ground truth. DRAM demonstrated an improved ability to propagate ROIs through free-breathing small bowel and colonic motility data, with median error decreased by 90% and 55%, respectively. Comparison between global parametric maps showed high concordance between breath-hold data and free-breathing DRAM. Quantification of segmental and global motility in dynamic MR data is more accurate and robust to respiration when using the DRAM approach.
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Affiliation(s)
- A Menys
- Centre for Medical Imaging, 3rd Floor East, 250 Euston Road London NW1 2PG, UCL Division of Medicine, London, UK
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246
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Multimodal neuroimaging in humans at 9.4 T: a technological breakthrough towards an advanced metabolic imaging scanner. Brain Struct Funct 2014; 220:1867-84. [PMID: 25017191 DOI: 10.1007/s00429-014-0843-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 07/02/2014] [Indexed: 10/25/2022]
Abstract
The aim of this paper is twofold: firstly, to explore the potential of simultaneously acquiring multimodal MR-PET-EEG data in a human 9.4 T scanner to provide a platform for metabolic brain imaging. Secondly, to demonstrate that the three modalities are complementary, with MRI providing excellent structural and functional imaging, PET providing quantitative molecular imaging, and EEG providing superior temporal resolution. A 9.4 T MRI scanner equipped with a PET insert and a commercially available EEG device was used to acquire in vivo proton-based images, spectra, and sodium- and oxygen-based images with MRI, EEG signals from a human subject in a static 9.4 T magnetic field, and demonstrate hybrid MR-PET capability in a rat model. High-resolution images of the in vivo human brain with an isotropic resolution of 0.5 mm and post-mortem brain images of the cerebellum with an isotropic resolution of 320 µm are presented. A (1)H spectrum was also acquired from 2 × 2 × 2 mm voxel in the brain allowing 12 metabolites to be identified. Imaging based on sodium and oxygen is demonstrated with isotropic resolutions of 2 and 5 mm, respectively. Auditory evoked potentials measured in a static field of 9.4 T are shown. Finally, hybrid MR-PET capability at 9.4 T in the human scanner is demonstrated in a rat model. Initial progress on the road to 9.4 T multimodal MR-PET-EEG is illustrated. Ultra-high resolution structural imaging, high-resolution images of the sodium distribution and proof-of-principle (17)O data are clearly demonstrated. Further, simultaneous MR-PET data are presented without artefacts and EEG data successfully corrected for the cardioballistic artefact at 9.4 T are presented.
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247
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De Martino F, Moerel M, Xu J, van de Moortele PF, Ugurbil K, Goebel R, Yacoub E, Formisano E. High-Resolution Mapping of Myeloarchitecture In Vivo: Localization of Auditory Areas in the Human Brain. Cereb Cortex 2014; 25:3394-405. [PMID: 24994817 DOI: 10.1093/cercor/bhu150] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The precise delineation of auditory areas in vivo remains problematic. Histological analysis of postmortem tissue indicates that the relation of areal borders to macroanatomical landmarks is variable across subjects. Furthermore, functional parcellation schemes based on measures of, for example, frequency preference (tonotopy) remain controversial. Here, we propose a 7 Tesla magnetic resonance imaging method that enables the anatomical delineation of auditory cortical areas in vivo and in individual brains, through the high-resolution visualization (0.6 × 0.6 × 0.6 mm(3)) of intracortical anatomical contrast related to myelin. The approach combines the acquisition and analysis of images with multiple MR contrasts (T1, T2*, and proton density). Compared with previous methods, the proposed solution is feasible at high fields and time efficient, which allows collecting myelin-related and functional images within the same measurement session. Our results show that a data-driven analysis of cortical depth-dependent profiles of anatomical contrast allows identifying a most densely myelinated cortical region on the medial Heschl's gyrus. Analyses of functional responses show that this region includes neuronal populations with typical primary functional properties (single tonotopic gradient and narrow frequency tuning), thus indicating that it may correspond to the human homolog of monkey A1.
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Affiliation(s)
- Federico De Martino
- Department of Cognitive Neurosciences, Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, 55455 Minneapolis, MN, USA
| | - Michelle Moerel
- Department of Cognitive Neurosciences, Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Junqian Xu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, 55455 Minneapolis, MN, USA Icahn School of Medicine Mount Sinai, 10029-6574 New York, NY, USA
| | | | - Kamil Ugurbil
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, 55455 Minneapolis, MN, USA
| | - Rainer Goebel
- Department of Cognitive Neurosciences, Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Essa Yacoub
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, 55455 Minneapolis, MN, USA
| | - Elia Formisano
- Department of Cognitive Neurosciences, Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands
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248
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Gumus K, Keating B, Poser BA, Armstrong B, Chang L, Maclaren J, Prieto T, Speck O, Zaitsev M, Ernst T. Prevention of motion-induced signal loss in diffusion-weighted echo-planar imaging by dynamic restoration of gradient moments. Magn Reson Med 2014; 71:2006-13. [PMID: 23821373 PMCID: PMC4420624 DOI: 10.1002/mrm.24857] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 05/10/2013] [Accepted: 06/05/2013] [Indexed: 11/11/2022]
Abstract
PURPOSE Head motion is a significant problem in diffusion-weighted imaging as it may cause signal attenuation due to residual dephasing during strong diffusion encoding gradients even in single-shot acquisitions. Here, we present a new real-time method to prevent motion-induced signal loss in DWI of the brain. METHODS The method requires a fast motion tracking system (optical in the current implementation). Two alterations were made to a standard diffusion-weighted echo-planar imaging sequence: first, real-time motion correction ensures that slices are correctly aligned relative to the moving brain. Second, the tracking data are used to calculate the motion-induced gradient moment imbalance which occurs during the diffusion encoding periods, and a brief gradient blip is inserted immediately prior to the signal readout to restore the gradient moment balance. RESULTS Phantom experiments show that the direction as well as magnitude of the gradient moment imbalance affects the characteristics of unwanted signal attenuation. In human subjects, the addition of a moment-restoring blip prevented signal loss and improved the reproducibility and reliability of diffusion tensor measures even in the presence of substantial head movements. CONCLUSION The method presented can improve robustness for clinical routine scanning in populations that are prone to head movements, such as children and uncooperative adult patients.
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Affiliation(s)
- Kazim Gumus
- Department of Medicine, JABSOM, University of Hawaii, Honolulu, Hawaii, USA
| | - Brian Keating
- Department of Medicine, JABSOM, University of Hawaii, Honolulu, Hawaii, USA
| | - Benedikt A. Poser
- Department of Medicine, JABSOM, University of Hawaii, Honolulu, Hawaii, USA
| | - Brian Armstrong
- Department of Electrical Engineering and Computer Science, University of Wisconsin Milwaukee, Milwaukee, Wisconsin, USA
| | - Linda Chang
- Department of Medicine, JABSOM, University of Hawaii, Honolulu, Hawaii, USA
| | - Julian Maclaren
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Thomas Prieto
- Department of Neurology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Oliver Speck
- Biomedical Magnetic Resonance, Otto von Guericke University, Magde burg, Germany
- Leibniz Institute for Neurobiology, Magdeburg, Germany
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| | - Maxim Zaitsev
- Department of Radiology, University Medical Center Freiburg, Freiburg, Germany
| | - Thomas Ernst
- Department of Medicine, JABSOM, University of Hawaii, Honolulu, Hawaii, USA
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249
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Kanowski M, Voges J, Buentjen L, Stadler J, Heinze HJ, Tempelmann C. Direct visualization of anatomic subfields within the superior aspect of the human lateral thalamus by MRI at 7T. AJNR Am J Neuroradiol 2014; 35:1721-7. [PMID: 24852290 DOI: 10.3174/ajnr.a3951] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The morphology of the human thalamus shows high interindividual variability. Therefore, direct visualization of landmarks within the thalamus is essential for an improved definition of electrode positions for deep brain stimulation. The aim of this study was to provide anatomic detail in the thalamus by using inversion recovery TSE imaging at 7T. MATERIALS AND METHODS The MR imaging protocol was optimized on 1 healthy subject to segment thalamic nuclei from one another. Final images, acquired with 0.5(2)-mm2 in-plane resolution and 3-mm section thickness, were compared with stereotactic brain atlases to assign visualized details to known anatomy. The robustness of the visualization of thalamic nuclei was assessed with 4 healthy subjects at lower image resolution. RESULTS Thalamic subfields were successfully delineated in the dorsal aspect of the lateral thalamus. T1-weighting was essential. MR images had an appearance very similar to that of myelin-stained sections seen in brain atlases. Visualized intrathalamic structures were, among others, the lamella medialis, the external medullary lamina, the reticulatum thalami, the nucleus centre médian, the boundary between the nuclei dorso-oralis internus and externus, and the boundary between the nuclei dorso-oralis internus and zentrolateralis intermedius internus. CONCLUSIONS Inversion recovery-prepared TSE imaging at 7T has a high potential to reveal fine anatomic detail in the thalamus, which may be helpful in enhancing the planning of stereotactic neurosurgery in the future.
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Affiliation(s)
- M Kanowski
- From the Departments of Neurology (M.K., H.-J.H., C.T.)
| | - J Voges
- Stereotactic Neurosurgery (J.V., L.B.), Otto-von-Guericke-University Magdeburg, Magdeburg, Germany Leibniz Institute for Neurobiology Magdeburg (J.V., J.S., H.-J.H.), Magdeburg, Germany
| | - L Buentjen
- Stereotactic Neurosurgery (J.V., L.B.), Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - J Stadler
- Leibniz Institute for Neurobiology Magdeburg (J.V., J.S., H.-J.H.), Magdeburg, Germany
| | - H-J Heinze
- From the Departments of Neurology (M.K., H.-J.H., C.T.) Leibniz Institute for Neurobiology Magdeburg (J.V., J.S., H.-J.H.), Magdeburg, Germany German Center for Neurodegenerative Diseases (H.-J.H.), Magdeburg, Germany
| | - C Tempelmann
- From the Departments of Neurology (M.K., H.-J.H., C.T.)
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250
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Yarach U, Luengviriya C, Danishad A, Stucht D, Godenschweger F, Schulze P, Speck O. Correction of gradient nonlinearity artifacts in prospective motion correction for 7T MRI. Magn Reson Med 2014; 73:1562-9. [PMID: 24798889 DOI: 10.1002/mrm.25283] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 04/07/2014] [Accepted: 04/15/2014] [Indexed: 11/11/2022]
Abstract
PURPOSE To demonstrate the effect of gradient nonlinearity and develop a method for correction of gradient nonlinearity artifacts in prospective motion correction (Mo-Co). METHODS Nonlinear gradients can induce geometric distortions in magnetic resonance imaging, leading to pixel shifts with errors of up to several millimeters, thereby interfering with precise localization of anatomical structures. Prospective Mo-Co has been extended by conventional gradient warp correction applied to individual phase encoding steps/groups during the reconstruction. The gradient-related displacements are approximated using spherical harmonic functions. In addition, the combination of this method with a retrospective correction of the changes in the coil sensitivity profiles relative to the object (augmented sensitivity encoding (SENSE) reconstruction) was evaluated in simulation and experimental data. RESULTS Prospective Mo-Co under gradient fields and coils sensitivity inconsistencies results in residual blurring, spatial distortion, and coil sensitivity mismatch artifacts. These errors can be considerably mitigated by the proposed method. High image quality with very little remaining artifacts was achieved after a few iterations. The relative image errors decreased from 25.7% to below 17.3% after 10 iterations. CONCLUSION The combined correction of gradient nonlinearity and sensitivity map variation leads to a pronounced reduction of residual motion artifacts in prospectively motion-corrected data.
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Affiliation(s)
- Uten Yarach
- Department of Biomedical Magnetic Resonance, Otto-von-Guericke University Magdeburg, Magdeburg, Germany; Department of Radiological Technology, Chiangmai University, Chiang Mai, Thailand
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