101
|
Liu J, de Zwart JA, van Gelderen P, Murphy-Boesch J, Duyn JH. Effect of head motion on MRI B 0 field distribution. Magn Reson Med 2018; 80:2538-2548. [PMID: 29770481 PMCID: PMC6239980 DOI: 10.1002/mrm.27339] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 04/05/2018] [Accepted: 04/05/2018] [Indexed: 01/07/2023]
Abstract
PURPOSE To identify and characterize the sources of B0 field changes due to head motion, to reduce motion sensitivity in human brain MRI. METHODS B0 fields were measured in 5 healthy human volunteers at various head poses. After measurement of the total field, the field originating from the subject was calculated by subtracting the external field generated by the magnet and shims. A subject-specific susceptibility model was created to quantify the contribution of the head and torso. The spatial complexity of the field changes was analyzed using spherical harmonic expansion. RESULTS Minor head pose changes can cause substantial and spatially complex field changes in the brain. For rotations and translations of approximately 5 º and 5 mm, respectively, at 7 T, the field change that is associated with the subject's magnetization generates a standard deviation (SD) of about 10 Hz over the brain. The stationary torso contributes to this subject-associated field change significantly with a SD of about 5 Hz. The subject-associated change leads to image-corrupting phase errors in multi-shot <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:msubsup><mml:mi>T</mml:mi> <mml:mn>2</mml:mn> <mml:mo>*</mml:mo></mml:msubsup> </mml:mrow> </mml:math> -weighted acquisitions. CONCLUSION The B0 field changes arising from head motion are problematic for multishot <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow><mml:msubsup><mml:mi>T</mml:mi> <mml:mn>2</mml:mn> <mml:mo>*</mml:mo></mml:msubsup> </mml:mrow> </mml:math> -weighted imaging. Characterization of the underlying sources provides new insights into mitigation strategies, which may benefit from individualized predictive field models in addition to real-time field monitoring and correction strategies.
Collapse
Affiliation(s)
- Jiaen Liu
- Advanced MRI, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Jacco A de Zwart
- Advanced MRI, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Peter van Gelderen
- Advanced MRI, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Joseph Murphy-Boesch
- Advanced MRI, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Jeff H Duyn
- Advanced MRI, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| |
Collapse
|
102
|
Mehta BB, Ma D, Pierre EY, Jiang Y, Coppo S, Griswold MA. Image reconstruction algorithm for motion insensitive MR Fingerprinting (MRF): MORF. Magn Reson Med 2018; 80:2485-2500. [PMID: 29732610 DOI: 10.1002/mrm.27227] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 03/24/2018] [Accepted: 03/28/2018] [Indexed: 12/15/2022]
Abstract
PURPOSE The purpose of this study is to increase the robustness of MR fingerprinting (MRF) toward subject motion. METHODS A novel reconstruction algorithm, MOtion insensitive MRF (MORF), was developed, which uses an iterative reconstruction based retrospective motion correction approach. Each iteration loops through the following steps: pattern recognition, metric based identification of motion corrupted frames, registration based motion estimation, and motion compensated data consistency verification. The proposed algorithm was validated using in vivo 2D brain MRF data with retrospective in-plane motion introduced at different stages of the acquisition. The validation was performed using qualitative and quantitative comparisons between results from MORF, the iterative multi-scale (IMS) algorithm, and with the IMS results using data without motion for a ground truth comparison. Additionally, the MORF algorithm was evaluated in prospectively motion corrupted in vivo 2D brain MRF datasets. RESULTS For datasets corrupted by in-plane motion both prospectively and retrospectively, MORF noticeably reduced motion artifacts compared with iterative multi-scale and closely resembled the results from data without motion, even when ∼54% of data was motion corrupted during different parts of the acquisition. CONCLUSIONS MORF improves the insensitivity of MRF toward rigid-body motion occurring during any part of the MRF acquisition.
Collapse
Affiliation(s)
| | - Dan Ma
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio
| | - Eric Yann Pierre
- Imaging Division, The Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia
| | - Yun Jiang
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio
| | - Simone Coppo
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio
| | - Mark Alan Griswold
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio.,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio
| |
Collapse
|
103
|
Castella R, Arn L, Dupuis E, Callaghan MF, Draganski B, Lutti A. Controlling motion artefact levels in MR images by suspending data acquisition during periods of head motion. Magn Reson Med 2018; 80:2415-2426. [DOI: 10.1002/mrm.27214] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 02/20/2018] [Accepted: 03/18/2018] [Indexed: 01/28/2023]
Affiliation(s)
- Rémi Castella
- LREN, Department for Clinical Neurosciences; CHUV; Lausanne Switzerland
| | - Lionel Arn
- LREN, Department for Clinical Neurosciences; CHUV; Lausanne Switzerland
- Ecole Polytechnique Fédérale de Lausanne; Lausanne Switzerland
| | - Estelle Dupuis
- LREN, Department for Clinical Neurosciences; CHUV; Lausanne Switzerland
| | - Martina F. Callaghan
- Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology; University College London; London United Kingdom
| | - Bogdan Draganski
- LREN, Department for Clinical Neurosciences; CHUV; Lausanne Switzerland
- Max Planck Institute for Human Cognitive and Brain Sciences; Leipzig Germany
| | - Antoine Lutti
- LREN, Department for Clinical Neurosciences; CHUV; Lausanne Switzerland
| |
Collapse
|
104
|
Bednarz HM, Kana RK. Advances, challenges, and promises in pediatric neuroimaging of neurodevelopmental disorders. Neurosci Biobehav Rev 2018; 90:50-69. [PMID: 29608989 DOI: 10.1016/j.neubiorev.2018.03.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 02/26/2018] [Accepted: 03/22/2018] [Indexed: 10/17/2022]
Abstract
Recent years have witnessed the proliferation of neuroimaging studies of neurodevelopmental disorders (NDDs), particularly of children with autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and Tourette's syndrome (TS). Neuroimaging offers immense potential in understanding the biology of these disorders, and how it relates to clinical symptoms. Neuroimaging techniques, in the long run, may help identify neurobiological markers to assist clinical diagnosis and treatment. However, methodological challenges have affected the progress of clinical neuroimaging. This paper reviews the methodological challenges involved in imaging children with NDDs. Specific topics include correcting for head motion, normalization using pediatric brain templates, accounting for psychotropic medication use, delineating complex developmental trajectories, and overcoming smaller sample sizes. The potential of neuroimaging-based biomarkers and the utility of implementing neuroimaging in a clinical setting are also discussed. Data-sharing approaches, technological advances, and an increase in the number of longitudinal, prospective studies are recommended as future directions. Significant advances have been made already, and future decades will continue to see innovative progress in neuroimaging research endeavors of NDDs.
Collapse
Affiliation(s)
- Haley M Bednarz
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Rajesh K Kana
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA.
| |
Collapse
|
105
|
Engel M, Kasper L, Barmet C, Schmid T, Vionnet L, Wilm B, Pruessmann KP. Single‐shot spiral imaging at 7
T. Magn Reson Med 2018; 80:1836-1846. [DOI: 10.1002/mrm.27176] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 02/15/2018] [Accepted: 02/18/2018] [Indexed: 01/18/2023]
Affiliation(s)
- Maria Engel
- Institute for Biomedical EngineeringETH Zurich and University of ZurichZurich Switzerland
| | - Lars Kasper
- Institute for Biomedical EngineeringETH Zurich and University of ZurichZurich Switzerland
- Translational Neuromodeling Unit, Institute for Biomedical EngineeringUniversity of Zurich and ETH ZurichZurich Switzerland
| | - Christoph Barmet
- Institute for Biomedical EngineeringETH Zurich and University of ZurichZurich Switzerland
- Skope Magnetic Resonance Technologies AGZurich Switzerland
| | - Thomas Schmid
- Institute for Biomedical EngineeringETH Zurich and University of ZurichZurich Switzerland
| | - Laetitia Vionnet
- Institute for Biomedical EngineeringETH Zurich and University of ZurichZurich Switzerland
| | - Bertram Wilm
- Institute for Biomedical EngineeringETH Zurich and University of ZurichZurich Switzerland
- Skope Magnetic Resonance Technologies AGZurich Switzerland
| | - Klaas P. Pruessmann
- Institute for Biomedical EngineeringETH Zurich and University of ZurichZurich Switzerland
| |
Collapse
|
106
|
Computational neuroanatomy of baby brains: A review. Neuroimage 2018; 185:906-925. [PMID: 29574033 DOI: 10.1016/j.neuroimage.2018.03.042] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Revised: 02/23/2018] [Accepted: 03/19/2018] [Indexed: 12/12/2022] Open
Abstract
The first postnatal years are an exceptionally dynamic and critical period of structural, functional and connectivity development of the human brain. The increasing availability of non-invasive infant brain MR images provides unprecedented opportunities for accurate and reliable charting of dynamic early brain developmental trajectories in understanding normative and aberrant growth. However, infant brain MR images typically exhibit reduced tissue contrast (especially around 6 months of age), large within-tissue intensity variations, and regionally-heterogeneous, dynamic changes, in comparison with adult brain MR images. Consequently, the existing computational tools developed typically for adult brains are not suitable for infant brain MR image processing. To address these challenges, many infant-tailored computational methods have been proposed for computational neuroanatomy of infant brains. In this review paper, we provide a comprehensive review of the state-of-the-art computational methods for infant brain MRI processing and analysis, which have advanced our understanding of early postnatal brain development. We also summarize publically available infant-dedicated resources, including MRI datasets, computational tools, grand challenges, and brain atlases. Finally, we discuss the limitations in current research and suggest potential future research directions.
Collapse
|
107
|
Hoinkiss DC, Porter DA. Prospective motion correction in 2D multishot MRI using EPI navigators and multislice-to-volume image registration. Magn Reson Med 2017; 78:2127-2135. [PMID: 28983957 DOI: 10.1002/mrm.26951] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 09/06/2017] [Accepted: 09/09/2017] [Indexed: 11/05/2022]
Abstract
PURPOSE Prospective motion correction reduces artifacts in MRI by correcting for subject motion in real time, but techniques are limited for multishot 2-dimensional (2D) sequences. This study addresses this limitation by using 2D echo-planar imaging (EPI) slice navigator acquisitions together with a multislice-to-volume image registration. METHODS The 2D-EPI navigators were integrated into 2D imaging sequences to allow a rapid, real-time motion correction based on the registration of three navigator slices to a reference volume. A dedicated slice-iteration scheme was used to limit mutual spin-saturation effects between navigator and image data. The method was evaluated using T2 -weighted spin echo and multishot rapid acquisition with relaxation enhancement (RARE) sequences, and its motion-correction capabilities were compared with those of periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER). Validation was performed in vivo using a well-defined motion protocol. RESULTS Data acquired during subject motion showed residual motion parameters within ±0.5 mm and ±0.5°, and demonstrated a substantial improvement in image quality compared with uncorrected scans. In a comparison to PROPELLER, the proposed technique preserved a higher level of anatomical detail in the presence of subject motion. CONCLUSIONS EPI-navigator-based prospective motion correction using multislice-to-volume image registration can substantially reduce image artifacts, while minimizing spin-saturation effects. The method can be adapted for use in other 2D MRI sequences and promises to improve image quality in routine clinical examinations. Magn Reson Med 78:2127-2135, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
Collapse
|
108
|
Power JD, Plitt M, Kundu P, Bandettini PA, Martin A. Temporal interpolation alters motion in fMRI scans: Magnitudes and consequences for artifact detection. PLoS One 2017; 12:e0182939. [PMID: 28880888 PMCID: PMC5589107 DOI: 10.1371/journal.pone.0182939] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Accepted: 07/26/2017] [Indexed: 11/19/2022] Open
Abstract
Head motion can be estimated at any point of fMRI image processing. Processing steps involving temporal interpolation (e.g., slice time correction or outlier replacement) often precede motion estimation in the literature. From first principles it can be anticipated that temporal interpolation will alter head motion in a scan. Here we demonstrate this effect and its consequences in five large fMRI datasets. Estimated head motion was reduced by 10–50% or more following temporal interpolation, and reductions were often visible to the naked eye. Such reductions make the data seem to be of improved quality. Such reductions also degrade the sensitivity of analyses aimed at detecting motion-related artifact and can cause a dataset with artifact to falsely appear artifact-free. These reduced motion estimates will be particularly problematic for studies needing estimates of motion in time, such as studies of dynamics. Based on these findings, it is sensible to obtain motion estimates prior to any image processing (regardless of subsequent processing steps and the actual timing of motion correction procedures, which need not be changed). We also find that outlier replacement procedures change signals almost entirely during times of motion and therefore have notable similarities to motion-targeting censoring strategies (which withhold or replace signals entirely during times of motion).
Collapse
Affiliation(s)
- Jonathan D. Power
- National Institute of Mental Health, National Institute of Health, Bethesda, Maryland, United States of America
- * E-mail:
| | - Mark Plitt
- National Institute of Mental Health, National Institute of Health, Bethesda, Maryland, United States of America
| | - Prantik Kundu
- Department of Radiology, Mount Sinai Hospital, New York City, New York, United States of America
| | - Peter A. Bandettini
- National Institute of Mental Health, National Institute of Health, Bethesda, Maryland, United States of America
| | - Alex Martin
- National Institute of Mental Health, National Institute of Health, Bethesda, Maryland, United States of America
| |
Collapse
|
109
|
Aranovitch A, Haeberlin M, Gross S, Dietrich BE, Wilm BJ, Brunner DO, Schmid T, Luechinger R, Pruessmann KP. Prospective motion correction with NMR markers using only native sequence elements. Magn Reson Med 2017; 79:2046-2056. [PMID: 28840611 DOI: 10.1002/mrm.26877] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 07/27/2017] [Accepted: 07/29/2017] [Indexed: 12/20/2022]
Abstract
PURPOSE To develop a method of tracking active NMR markers that requires no alterations of common imaging sequences and can be used for prospective motion correction (PMC) in brain MRI. METHODS Localization of NMR markers is achieved by acquiring short signal snippets in rapid succession and evaluating them jointly. To spatially encode the markers, snippets are timed such that signal phase is accrued during sequence intervals with suitably diverse gradient actuation. For motion tracking and PMC in brain imaging, the markers are mounted on a lightweight headset. PMC is then demonstrated with high-resolution T2 *- and T1 -weighted imaging sequences in the presence of instructed as well as residual unintentional head motion. RESULTS With both unaltered sequences, motion tracking was achieved with precisions on the order of 10 µm and 0.01° and temporal resolution of 48 and 39 ms, respectively. On this basis, PMC improved image quality significantly throughout. CONCLUSION The proposed approach permits high-precision motion tracking and PMC with standard imaging sequences. It does so without altering sequence design and thus overcomes a key hindrance to routine motion tracking with NMR markers. Magn Reson Med 79:2046-2057, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Alexander Aranovitch
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Maximilian Haeberlin
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Simon Gross
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Benjamin E Dietrich
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Bertram J Wilm
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - David O Brunner
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Thomas Schmid
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Roger Luechinger
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Klaas P Pruessmann
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
| |
Collapse
|
110
|
Maclaren J, Aksoy M, Ooi MB, Zahneisen B, Bammer R. Prospective motion correction using coil-mounted cameras: Cross-calibration considerations. Magn Reson Med 2017; 79:1911-1921. [PMID: 28722314 DOI: 10.1002/mrm.26838] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 06/23/2017] [Accepted: 06/23/2017] [Indexed: 12/11/2022]
Abstract
PURPOSE Optical prospective motion correction substantially reduces sensitivity to motion in neuroimaging of human subjects. However, a major barrier to clinical deployment has been the time-consuming cross-calibration between the camera and MRI scanner reference frames. This work addresses this challenge. METHODS A single camera was mounted onto the head coil for tracking head motion. Two new methods were developed: (1) a rapid calibration method for camera-to-scanner cross-calibration using a custom-made tool incorporating wireless active markers, and (2) a calibration adjustment method to compensate for table motion between scans. Both methods were tested at 1.5T and 3T in vivo. Simulations were performed to determine the required mechanical tolerance for repositioning of the camera. RESULTS The rapid calibration method is completed in a short (<30 s) scan, which is carried out only once per installation. The calibration adjustment method requires no extra scan time and runs automatically whenever the system is used. The mechanical tolerance analysis indicates that most motion (90% reduction in voxel displacement) could be corrected even with far larger camera repositioning errors than are observed in practice. CONCLUSION The methods presented here allow calibration of sufficient quality to be carried out and maintained with no additional technologist workload. Magn Reson Med 79:1911-1921, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Julian Maclaren
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Murat Aksoy
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Melvyn B Ooi
- Department of Radiology, Stanford University, Stanford, California, USA.,Philips Healthcare, Gainesville, Florida, USA
| | | | - Roland Bammer
- Department of Radiology, Stanford University, Stanford, California, USA
| |
Collapse
|
111
|
Güttler F, Heinrich A, Krauß P, Guntermann J, de Bucourt M, Teichgräber U. RFID-Based Real-Time Navigation for Interventional Magnetic Resonance Imaging: Development and Evaluation of a Novel Tracking System. J Med Device 2017. [DOI: 10.1115/1.4036337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The purpose of this study was to evaluate the suitability of a novel radio-frequency identification (RFID)-based tracking system for intraoperative magnetic resonance imaging (MRI). A RFID tracking system was modified to fulfill MRI-compatibility and tested according to ASTM and NEMA. The influence of the RFID tracking system on MRI was analyzed in a phantom study using a half-Fourier acquisition single-shot turbospin echo (HASTE) and true fast imaging with steady-state precession sequence (TrueFISP) sequence. The RFID antenna was gradually moved closer to the isocenter of the MR scanner from 90 to 210 cm to investigate the influence of the distance. Furthermore, the RF was gradually changed between 865 and 869 MHz for a distance of 90 cm, 150 cm, and 210 cm to the isocenter of the magnet to investigate the influence of the frequency. The specific spatial resolution was measured with and without a permanent line of sight (LOS). After the modification of the reader, no significant change of the signal-to-noise ratio (SNR) could be observed with increasing distance of the RFID tracking system to the isocenter of the MR scanner. Also, different radio frequencies of the RFID tracking system did not influence the SNR of the MR-images significantly. The specific spatial resolution deviated on average by 8.97 ± 7.33 mm with LOS and 11.23 ± 12.03 mm without LOS from the reference system. The RFID tracking system had no relevant influence on the MR-image quality. RFID tracking solved the LOS problem. However, the spatial accuracy of the RFID tracking system has to be improved for medical usage.
Collapse
Affiliation(s)
- Felix Güttler
- Department of Radiology, University Hospital Jena, Am Klinikum 1, Jena 07747, Germany e-mail:
| | - Andreas Heinrich
- Department of Radiology, University Hospital Jena, Am Klinikum 1, Jena 07747, Germany e-mail:
| | - Peter Krauß
- Department of Radiology, Charité University Hospital, Charitépl. 1, Berlin 10117, Germany
| | - Jonathan Guntermann
- Department of Radiology, Charité University Hospital, Charitépl. 1, Berlin 10117, Germany
| | - Maximilian de Bucourt
- Department of Radiology, Charité University Hospital, Charitépl. 1, Berlin 10117, Germany e-mail:
| | - Ulf Teichgräber
- Department of Radiology, University Hospital Jena, Am Klinikum 1, Jena 07747, Germany e-mail:
| |
Collapse
|
112
|
Yakupov R, Lei J, Hoffmann MB, Speck O. False fMRI activation after motion correction. Hum Brain Mapp 2017; 38:4497-4510. [PMID: 28580597 DOI: 10.1002/hbm.23677] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 05/22/2017] [Accepted: 05/24/2017] [Indexed: 12/23/2022] Open
Abstract
Motion correction of echo-planar imaging (EPI) data used in functional MRI (fMRI) is an essential preprocessing step performed prior to statistical analysis. At ultra-high resolution fMRI, current requirements regarding translational and rotational motion may no longer be acceptable. This prompts the need for a systematic investigation of the effects of motion correction procedures with in vivo fMRI data. Here we systematically evaluated the effect of retrospective motion correction with freely available fMRI analysis software packages (FSL, AFNI, and SPM) on activation maps using fMRI data acquired with prospective motion detection, to identify and quantify confounding effects of retrospective motion correction, and to evaluate its dependence on spatial resolution and motion correction algorithms. Brain activation maps were obtained for two different resolutions, an ultrahigh, that is, 0.653 mm3 , and a more widely used 2.03 mm3 isotropic resolutions at 7 T. The EPI data were acquired using simultaneous non-image-based optical moiré phase tracking (MPT) of physical motion. The results showed that image-based motion detection, performed by SPM8 software package, may be erroneous in high-field fMRI data with partial brain coverage and can introduce spurious motion leading to false-positive and false-negative activation. Further analyses demonstrated that limited acquisition field of view has the dominant influence on the effect. Hum Brain Mapp 38:4497-4510, 2017. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Renat Yakupov
- Biomedical Magnetic Resonance, Otto-von-Guericke University, Magdeburg, Germany
| | - Juan Lei
- Visual Processing Laboratory, Department of Ophthalmology, Otto-von-Guericke University, Magdeburg, Germany.,Brain Imaging Center, Frankfurt, Germany.,Department of Neurology, Goethe University, Frankfurt, Germany
| | - Michael B Hoffmann
- Visual Processing Laboratory, Department of Ophthalmology, Otto-von-Guericke University, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Oliver Speck
- Biomedical Magnetic Resonance, Otto-von-Guericke University, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany.,Leibniz Institute for Neurobiology, Magdeburg, Germany.,German Center for Neurodegenerative Disease, Magdeburg, Germany
| |
Collapse
|
113
|
Havsteen I, Ohlhues A, Madsen KH, Nybing JD, Christensen H, Christensen A. Are Movement Artifacts in Magnetic Resonance Imaging a Real Problem?-A Narrative Review. Front Neurol 2017; 8:232. [PMID: 28611728 PMCID: PMC5447676 DOI: 10.3389/fneur.2017.00232] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Accepted: 05/12/2017] [Indexed: 12/29/2022] Open
Abstract
Movement artifacts compromise image quality and may interfere with interpretation, especially in magnetic resonance imaging (MRI) applications with low signal-to-noise ratio such as functional MRI or diffusion tensor imaging, and when imaging small lesions. High image resolution has high sensitivity to motion artifacts and often prolongs scan time that again aggravates movement artifacts. During the scan fast imaging techniques and sequences, optimal receiver coils, careful patient positioning, and instruction may minimize movement artifacts. Physiological noise sources are motion from respiration, flow and pulse coupled to cardiac cycles, from the swallowing reflex and small spontaneous head movements. Par example, in resting-state functional MRI spontaneous neuronal activity adds 1–2% of signal change, even under optimal conditions signal contributions from physiological noise remain a considerable fraction hereof. Movement tracking during imaging may allow for prospective correction or postprocessing steps separating signal and noise.
Collapse
Affiliation(s)
- Inger Havsteen
- Department of Radiology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark
| | - Anders Ohlhues
- Department of Clinical Engineering Diagnostic Imaging Section, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Kristoffer H Madsen
- Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Janus Damm Nybing
- Department of Radiology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark
| | - Hanne Christensen
- Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark
| | - Anders Christensen
- Department of Radiology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark
| |
Collapse
|
114
|
van Niekerk A, van der Kouwe A, Meintjes E. A Method for Measuring Orientation Within a Magnetic Resonance Imaging Scanner Using Gravity and the Static Magnetic Field (VectOrient). IEEE TRANSACTIONS ON MEDICAL IMAGING 2017; 36:1129-1139. [PMID: 28129151 PMCID: PMC5637283 DOI: 10.1109/tmi.2017.2652502] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In MRI brain imaging, subject motion limits obtainable image clarity. Due to the hardware layout of an MRI scanner, gradient excitations can be used to rapidly detect position. Orientation, however, is more difficult to detect and is commonly calculated by comparing the position measurements of multiple spatially constrained points to a reference dataset. The result is increased size of the apparatus the subject must wear, which can influence the imaging workflow. In optical based methods marker attachment sites are limited due to the line of sight requirement between the camera and marker, and an external reference frame is introduced. To address these challenges a method called VectOrient is proposed for orientation measurement that is based on vector observations of gravity and the MRI scanner's static magnetic field. A prototype device comprising of an accelerometer, magnetometer and angular rate sensor shows good MRI compatibility. Phantom scans of a pineapple with zero scanner specific calibration achieve comparable results to a rigid body registration algorithm with deviations less than 0.8 degrees over 28 degree changes in orientation. Dynamic performance shows potential for prospective motion correction as rapid changes in orientation (peak 20 degrees per second) can be corrected. The pulse sequence implemented achieves orientation updates with a latency estimated to be less than 12.7 ms, of which only a small fraction (<1 ms) is used for computing orientation from the raw sensor signals. The device is capable of quantifying subject respiration and heart rates. The proposed approach for orientation estimation could help address some limitations of existing methods such as orientation measurement range, temporal resolution, ease of use and marker placement.
Collapse
|
115
|
APOE moderates compensatory recruitment of neuronal resources during working memory processing in healthy older adults. Neurobiol Aging 2017; 56:127-137. [PMID: 28528773 DOI: 10.1016/j.neurobiolaging.2017.04.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/17/2017] [Accepted: 04/13/2017] [Indexed: 11/20/2022]
Abstract
The APOE ε4 allele increases the risk for sporadic Alzheimer's disease and modifies brain activation patterns of numerous cognitive domains. We assessed cognitively intact older adults with a letter n-back task to determine if previously observed increases in ε4 carriers' working-memory-related brain activation are compensatory such that they serve to maintain working memory function. Using multiple regression models, we identified interactions of APOE variant and age in bilateral hippocampus independently from task performance: ε4 carriers only showed a decrease in activation with increasing age, suggesting high sensitivity of fMRI data for detecting changes in Alzheimer's disease-relevant brain areas before cognitive decline. Moreover, we identified ε4 carriers to show higher activations in task-negative medial and task-positive inferior frontal areas along with better performance under high working memory load relative to non-ε4 carriers. The increased frontal recruitment is compatible with models of neuronal compensation, extends on existing evidence, and suggests that ε4 carriers require additional neuronal resources to successfully perform a demanding working memory task.
Collapse
|
116
|
Deistung A, Schweser F, Reichenbach JR. Overview of quantitative susceptibility mapping. NMR IN BIOMEDICINE 2017; 30:e3569. [PMID: 27434134 DOI: 10.1002/nbm.3569] [Citation(s) in RCA: 184] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 05/03/2016] [Accepted: 05/09/2016] [Indexed: 06/06/2023]
Abstract
Magnetic susceptibility describes the magnetizability of a material to an applied magnetic field and represents an important parameter in the field of MRI. With the recently introduced method of quantitative susceptibility mapping (QSM) and its conceptual extension to susceptibility tensor imaging (STI), the non-invasive assessment of this important physical quantity has become possible with MRI. Both methods solve the ill-posed inverse problem to determine the magnetic susceptibility from local magnetic fields. Whilst QSM allows the extraction of the spatial distribution of the bulk magnetic susceptibility from a single measurement, STI enables the quantification of magnetic susceptibility anisotropy, but requires multiple measurements with different orientations of the object relative to the main static magnetic field. In this review, we briefly recapitulate the fundamental theoretical foundation of QSM and STI, as well as computational strategies for the characterization of magnetic susceptibility with MRI phase data. In the second part, we provide an overview of current methodological and clinical applications of QSM with a focus on brain imaging. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Andreas Deistung
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
| | - Ferdinand Schweser
- Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, The State University of New York at Buffalo, NY, USA
- MRI Clinical and Translational Research Center, Jacobs School of Medicine and Biomedical Sciences, The State University of New York at Buffalo, NY, USA
| | - Jürgen R Reichenbach
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany
- Michael Stifel Center for Data-driven and Simulation Science Jena, Friedrich Schiller University Jena, Jena, Germany
| |
Collapse
|
117
|
Hoinkiss DC, Porter DA. Prospective motion correction in diffusion-weighted imaging using intermediate pseudo-trace-weighted images. Neuroimage 2017; 149:1-14. [PMID: 28011251 DOI: 10.1016/j.neuroimage.2016.12.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 11/12/2016] [Accepted: 12/19/2016] [Indexed: 10/20/2022] Open
Abstract
Subject head motion is a major challenge in diffusion-weighted imaging, which requires a precise alignment of images from different time points to allow a reliable quantification of diffusion parameters within each voxel. The technique requires long measurement times, making it highly sensitive to long-term subject motion, even when head restraint is used. Current methods of data analysis rely on retrospective motion correction, but there are potential benefits to using prospective motion correction, in which motion is tracked and compensated for during data acquisition. This technique is regularly used to enhance image quality in blood-oxygen-level dependent (BOLD) imaging, but its application to diffusion-weighted imaging has been limited by the contrast variation between images acquired with different diffusion-gradient directions. This paper describes a novel approach to this topic that exploits the rotational invariance of the trace of the diffusion tensor to reduce the effect of this contrast variation, making it possible to perform a fast image registration using a least-squares cost function. This results in an image-based motion detection algorithm that can be applied in real time during data acquisition to adapt the slice position and orientation in response to subject motion. The motion detection capabilities of the technique were evaluated in a study of ten subjects with b-values up to 3000s/mm². The resulting motion-parameter estimates were in close agreement with reference values provided by interleaved low-b-value images with a correlation coefficient of R=0.9634 for the voxel displacements measured across all subjects and b-values. The technique was also used to perform prospective motion correction on a standard clinical MRI system with b-values up to 2000s/mm². The correction was evaluated in 3 subjects using interleaved low-b-value images, retrospective image registration using the AFNI processing package and mean diffusivity histogram analysis. Compared to acquisitions without motion correction, prospective motion correction based on pseudo-trace-weighted images was found to provide a robust method for substantially reducing the level of misregistration between volumes. In most cases, misregistrations were reduced to less than 0.2mm of translation and 0.2° of rotation for an isotropic voxel size of 2mm, yielding high-quality diffusion parameter maps even in the absence of head restraint and post-acquisition image registration.
Collapse
|
118
|
Zahneisen B, Aksoy M, Maclaren J, Wuerslin C, Bammer R. Extended hybrid-space SENSE for EPI: Off-resonance and eddy current corrected joint interleaved blip-up/down reconstruction. Neuroimage 2017; 153:97-108. [PMID: 28359788 DOI: 10.1016/j.neuroimage.2017.03.052] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 03/21/2017] [Accepted: 03/22/2017] [Indexed: 11/16/2022] Open
Abstract
INTRODUCTION Geometric distortions along the phase encode direction caused by off-resonant spins are still a major issue in EPI based functional and diffusion imaging. If the off-resonance map is known it is possible to correct for distortions. Most correction methods operate as a post-processing step on the reconstructed magnitude images. THEORY AND METHODS Here, we present an algebraic reconstruction method (hybrid-space SENSE) that incorporates a physics based model of off-resonances, phase inconsistencies between k-space segments, and T2*-decay during the acquisition. The method can be used to perform a joint reconstruction of interleaved acquisitions with normal (blip-up) and inverted (blip-down) phase encode direction which results in reduced g-factor penalty. RESULTS A joint blip-up/down simultaneous multi slice (SMS) reconstruction for SMS-factor 4 in combination with twofold in-plane acceleration leads to a factor of two decrease in maximum g-factor penalty while providing off-resonance and eddy-current corrected images. CONCLUSION We provide an algebraic framework for reconstructing diffusion weighted EPI data that in addition to the general applicability of hybrid-space SENSE to 2D-EPI, SMS-EPI and 3D-EPI with arbitrary k-space coverage along z, allows for a modeling of arbitrary spatio-temporal effects during the acquisition period like off-resonances, phase inconsistencies and T2*-decay. The most immediate benefit is a reduction in g-factor penalty if an interleaved blip-up/down acquisition strategy is chosen which facilitates eddy current estimation and ensures no loss in k-space encoding in regions with strong off-resonance gradients.
Collapse
Affiliation(s)
- Benjamin Zahneisen
- Stanford University, Department of Radiology, Stanford, CA, United States.
| | - Murat Aksoy
- Stanford University, Department of Radiology, Stanford, CA, United States
| | - Julian Maclaren
- Stanford University, Department of Radiology, Stanford, CA, United States
| | - Christian Wuerslin
- Stanford University, Department of Radiology, Stanford, CA, United States
| | - Roland Bammer
- Stanford University, Department of Radiology, Stanford, CA, United States
| |
Collapse
|
119
|
T 1-weighted in vivo human whole brain MRI dataset with an ultrahigh isotropic resolution of 250 μm. Sci Data 2017; 4:170032. [PMID: 28291265 PMCID: PMC5349250 DOI: 10.1038/sdata.2017.32] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 02/08/2017] [Indexed: 11/08/2022] Open
Abstract
We present an ultrahigh resolution in vivo human brain magnetic resonance imaging (MRI) dataset. It consists of T1-weighted whole brain anatomical data acquired at 7 Tesla with a nominal isotropic resolution of 250 μm of a single young healthy Caucasian subject and was recorded using prospective motion correction. The raw data amounts to approximately 1.2 TB and was acquired in eight hours total scan time. The resolution of this dataset is far beyond any previously published in vivo structural whole brain dataset. Its potential use is to build an in vivo MR brain atlas. Methods for image reconstruction and image restoration can be improved as the raw data is made available. Pre-processing and segmentation procedures can possibly be enhanced for high magnetic field strength and ultrahigh resolution data. Furthermore, potential resolution induced changes in quantitative data analysis can be assessed, e.g., cortical thickness or volumetric measures, as high quality images with an isotropic resolution of 1 and 0.5 mm of the same subject are included in the repository as well.
Collapse
|
120
|
Jorge J, Gretsch F, Gallichan D, Marques JP. Tracking discrete off-resonance markers with three spokes (trackDOTS) for compensation of head motion and B0
perturbations: Accuracy and performance in anatomical imaging. Magn Reson Med 2017; 79:160-171. [DOI: 10.1002/mrm.26654] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 02/03/2017] [Accepted: 02/03/2017] [Indexed: 01/29/2023]
Affiliation(s)
- João Jorge
- Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne; Lausanne Switzerland
| | - Frédéric Gretsch
- Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne; Lausanne Switzerland
| | - Daniel Gallichan
- Biomedical Imaging Research Center, École Polytechnique Fédérale de Lausanne; Lausanne Switzerland
| | - José P. Marques
- Donders Institute; Radboud University; Nijmegen the Netherlands
| |
Collapse
|
121
|
High-resolution distortion-free diffusion imaging using hybrid spin-warp and echo-planar PSF-encoding approach. Neuroimage 2017; 148:20-30. [DOI: 10.1016/j.neuroimage.2017.01.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 12/09/2016] [Accepted: 01/04/2017] [Indexed: 11/21/2022] Open
|
122
|
Lange T, Knowles BR, Herbst M, Izadpanah K, Zaitsev M. Comparative T
2
and T
1ρ
mapping of patellofemoral cartilage under in situ mechanical loading with prospective motion correction. J Magn Reson Imaging 2017; 46:452-460. [DOI: 10.1002/jmri.25574] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/17/2016] [Indexed: 11/11/2022] Open
Affiliation(s)
- Thomas Lange
- Department of Radiology, Medical Physics; Medical Center - University of Freiburg, Faculty of Medicine; Freiburg Germany
| | - Benjamin R. Knowles
- Department of Radiology, Medical Physics; Medical Center - University of Freiburg, Faculty of Medicine; Freiburg Germany
| | - Michael Herbst
- Department of Radiology, Medical Physics; Medical Center - University of Freiburg, Faculty of Medicine; Freiburg Germany
- John A. Burns School of Medicine; University of Hawaii; Honolulu Hawaii USA
| | - Kaywan Izadpanah
- Department of Orthopedic and Trauma Surgery; Medical Center - University of Freiburg, Faculty of Medicine; Freiburg Germany
| | - Maxim Zaitsev
- Department of Radiology, Medical Physics; Medical Center - University of Freiburg, Faculty of Medicine; Freiburg Germany
| |
Collapse
|
123
|
Prospective motion correction for 3D pseudo-continuous arterial spin labeling using an external optical tracking system. Magn Reson Imaging 2017; 39:44-52. [PMID: 28137627 DOI: 10.1016/j.mri.2017.01.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 01/26/2017] [Accepted: 01/26/2017] [Indexed: 11/22/2022]
Abstract
Head motion is an unsolved problem in magnetic resonance imaging (MRI) studies of the brain. Real-time tracking using a camera has recently been proposed as a way to prevent head motion artifacts. As compared to navigator-based approaches that use MRI data to detect and correct motion, optical motion correction works independently of the MRI scanner, thus providing low-latency real-time motion updates without requiring any modifications to the pulse sequence. The purpose of this study was two-fold: 1) to demonstrate that prospective optical motion correction using an optical camera mitigates artifacts from head motion in three-dimensional pseudo-continuous arterial spin labeling (3D PCASL) acquisitions and 2) to assess the effect of latency differences between real-time optical motion tracking and navigator-style approaches (such as PROMO). An optical motion correction system comprising a single camera and a marker attached to the patient's forehead was used to track motion at a rate of 60fps. In the presence of motion, continuous tracking data from the optical system was used to update the scan plane in real-time during the 3D-PCASL acquisition. Navigator-style correction was simulated by using the tracking data from the optical system and performing updates only once per repetition time. Three normal volunteers and a patient were instructed to perform continuous and discrete head motion throughout the scan. Optical motion correction yielded superior image quality compared to uncorrected images or images using navigator-style correction. The standard deviations of pixel-wise CBF differences between reference and non-corrected, navigator-style-corrected and optical-corrected data were 14.28, 14.35 and 11.09mL/100g/min for continuous motion, and 12.42, 12.04 and 9.60mL/100g/min for discrete motion. Data obtained from the patient revealed that motion can obscure pathology and that application of optical prospective correction can successfully reveal the underlying pathology in the presence of head motion.
Collapse
|
124
|
Turner R, De Haan D. Bridging the gap between system and cell: The role of ultra-high field MRI in human neuroscience. PROGRESS IN BRAIN RESEARCH 2017; 233:179-220. [DOI: 10.1016/bs.pbr.2017.05.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
125
|
Usman M, Ruijsink B, Nazir MS, Cruz G, Prieto C. Free breathing whole-heart 3D CINE MRI with self-gated Cartesian trajectory. Magn Reson Imaging 2016; 38:129-137. [PMID: 28034638 PMCID: PMC5375620 DOI: 10.1016/j.mri.2016.12.021] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 12/22/2016] [Accepted: 12/22/2016] [Indexed: 01/22/2023]
Abstract
Purpose To present a method that uses a novel free-running self-gated acquisition to achieve isotropic resolution in whole heart 3D Cartesian cardiac CINE MRI. Material and methods 3D cardiac CINE MRI using navigator gating results in long acquisition times. Recently, several frameworks based on self-gated non-Cartesian trajectories have been proposed to accelerate this acquisition. However, non-Cartesian reconstructions are computationally expensive due to gridding, particularly in 3D. In this work, we propose a novel highly efficient self-gated Cartesian approach for 3D cardiac CINE MRI. Acquisition is performed using CArtesian trajectory with Spiral PRofile ordering and Tiny golden angle step for eddy current reduction (so called here CASPR-Tiger). Data is acquired continuously under free breathing (retrospective ECG gating, no preparation pulses interruption) for 4–5 min and 4D whole-heart volumes (3D + cardiac phases) with isotropic spatial resolution are reconstructed from all available data using a soft gating technique combined with temporal total variation (TV) constrained iterative SENSE reconstruction. Results For data acquired on eight healthy subjects and three patients, the reconstructed images using the proposed method had good contrast and spatio-temporal variations, correctly recovering diastolic and systolic cardiac phases. Non-significant differences (P > 0.05) were observed in cardiac functional measurements obtained with proposed 3D approach and gold standard 2D multi-slice breath-hold acquisition. Conclusion The proposed approach enables isotropic 3D whole heart Cartesian cardiac CINE MRI in 4 to 5 min free breathing acquisition. A novel self-gated 3D Cartesian acquisition is proposed for free breathing whole-heart cardiac MRI The proposed framework has efficient k-space sampling, better eddy current performance and high computational efficiency The Proposed method is able to achieve high spatio-temporal resolution 3D cardiac CINE The proposed method only requires four to five minute free breathing scan
Collapse
Affiliation(s)
- M Usman
- King's College London, Division of Imaging Sciences and Biomedical Engineering, London, United Kingdom; Department of Computer Science, University College London, London, UK.
| | - B Ruijsink
- King's College London, Division of Imaging Sciences and Biomedical Engineering, London, United Kingdom
| | - M S Nazir
- King's College London, Division of Imaging Sciences and Biomedical Engineering, London, United Kingdom
| | - G Cruz
- King's College London, Division of Imaging Sciences and Biomedical Engineering, London, United Kingdom
| | - C Prieto
- King's College London, Division of Imaging Sciences and Biomedical Engineering, London, United Kingdom; Pontificia Universidad Católica de Chile, Escuela de Ingeniería, Santiago, Chile
| |
Collapse
|
126
|
Herbst M, Poser BA, Singh A, Deng W, Knowles B, Zaitsev M, Stenger VA, Ernst T. Motion correction for diffusion weighted SMS imaging. Magn Reson Imaging 2016; 38:33-38. [PMID: 27988191 DOI: 10.1016/j.mri.2016.12.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 12/13/2016] [Accepted: 12/13/2016] [Indexed: 10/20/2022]
Affiliation(s)
- M Herbst
- Department of Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA; Department of Radiology, Medical Physics, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
| | - B A Poser
- Maastricht Brain Imaging Centre, Faculty of Psychology & Neuroscience, Maastricht University, Netherlands
| | - A Singh
- Department of Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA
| | - W Deng
- Department of Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA
| | - B Knowles
- Department of Radiology, Medical Physics, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - M Zaitsev
- Department of Radiology, Medical Physics, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - V A Stenger
- Department of Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA
| | - T Ernst
- Department of Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA
| |
Collapse
|
127
|
Zaitsev M, Akin B, LeVan P, Knowles BR. Prospective motion correction in functional MRI. Neuroimage 2016; 154:33-42. [PMID: 27845256 DOI: 10.1016/j.neuroimage.2016.11.014] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 11/04/2016] [Accepted: 11/05/2016] [Indexed: 10/20/2022] Open
Abstract
Due to the intrinsic low sensitivity of BOLD-fMRI long scanning is required. Subject motion during fMRI scans reduces statistical significance of the activation maps and increases the prevalence of false activations. Motion correction is therefore an essential tool for a successful fMRI data analysis. Retrospective motion correction techniques are now commonplace and are incorporated into a wide range of fMRI analysis toolboxes. These techniques are advantageous due to robustness, sequence independence and have minimal impact on the fMRI study setup. Retrospective techniques however, do not provide an accurate intra-volume correction, nor can these techniques correct for the spin-history effects. The application of prospective motion correction in fMRI appears to be effective in reducing false positives and increasing sensitivity when compared to retrospective techniques, particularly in the cases of substantial motion. Especially advantageous in this regard is the combination of prospective motion correction with dynamic distortion correction. Nevertheless, none of the recent methods are able to recover activations in presence of motion that are comparable to no-motion conditions, which motivates further research in the area of adaptive dynamic imaging.
Collapse
Affiliation(s)
- Maxim Zaitsev
- Department of Radiology - Medical Physics, University of Freiburg, Faculty of Medicine, University of Freiburg - Medical Centre, Freiburg, Germany.
| | - Burak Akin
- Department of Radiology - Medical Physics, University of Freiburg, Faculty of Medicine, University of Freiburg - Medical Centre, Freiburg, Germany
| | - Pierre LeVan
- Department of Radiology - Medical Physics, University of Freiburg, Faculty of Medicine, University of Freiburg - Medical Centre, Freiburg, Germany
| | - Benjamin R Knowles
- Department of Radiology - Medical Physics, University of Freiburg, Faculty of Medicine, University of Freiburg - Medical Centre, Freiburg, Germany
| |
Collapse
|
128
|
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.
Collapse
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
| |
Collapse
|
129
|
Zhang X, Ronen I, Kan HE, Teeuwisse WM, van Osch MJP. Time-efficient measurement of multi-phase arterial spin labeling MR signal in white matter. NMR IN BIOMEDICINE 2016; 29:1519-1525. [PMID: 27594277 DOI: 10.1002/nbm.3603] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 07/13/2016] [Accepted: 07/18/2016] [Indexed: 06/06/2023]
Abstract
White matter (WM) perfusion has great potential as a physiological biomarker in many neurological diseases. Although it has been demonstrated previously that arterial spin labeling magnetic resonance imaging (ASL-MRI) enables the detection of the perfusion-weighted signal in most voxels in WM, studies of cerebral blood flow (CBF) in WM by ASL-MRI are relatively scarce because of its particular challenges, such as significantly lower perfusion and longer arterial transit times relative to gray matter (GM). Recently, ASL with a spectroscopic readout has been proposed to enhance the sensitivity for the measurement of WM perfusion. However, this approach suffers from long acquisition times, especially when acquiring multi-phase ASL datasets to improve CBF quantification. Furthermore, the potential increase in the signal-to-noise ratio (SNR) by spectroscopic readout compared with echo planar imaging (EPI) readout has not been proven experimentally. In this study, we propose the use of time-encoded pseudo-continuous ASL (te-pCASL) with single-voxel point-resolved spectroscopy (PRESS) readout to quantify WM cerebral perfusion in a more time-efficient manner. Results are compared with te-pCASL with a conventional EPI readout for both WM and GM perfusion measurements. Perfusion measurements by te-pCASL PRESS and conventional EPI showed no significant difference for quantitative WM CBF values (Student's t-test, p = 0.19) or temporal SNR (p = 0.33 and p = 0.81 for GM and WM, respectively), whereas GM CBF values (p = 0.016) were higher using PRESS than EPI readout. WM CBF values were found to be 18.2 ± 7.6 mL/100 g/min (PRESS) and 12.5 ± 5.5 mL/100 g/min (EPI), whereas GM CBF values were found to be 77.1 ± 11.2 mL/100 g/min (PRESS) and 53.6 ± 9.6 mL/100 g/min (EPI). This study demonstrates the feasibility of te-pCASL PRESS for the quantification of WM perfusion changes in a highly time-efficient manner, but it does not result in improved temporal SNR, as does traditional te-pCASL EPI, which remains the preferred option because of its flexibility in use.
Collapse
Affiliation(s)
- X Zhang
- Department of Radiology, C. J. Gorter Center for High-Field MRI, Leiden University Medical Center, Leiden, the Netherlands.
| | - I Ronen
- Department of Radiology, C. J. Gorter Center for High-Field MRI, Leiden University Medical Center, Leiden, the Netherlands
| | - H E Kan
- Department of Radiology, C. J. Gorter Center for High-Field MRI, Leiden University Medical Center, Leiden, the Netherlands
| | - W M Teeuwisse
- Department of Radiology, C. J. Gorter Center for High-Field MRI, Leiden University Medical Center, Leiden, the Netherlands
| | - M J P van Osch
- Department of Radiology, C. J. Gorter Center for High-Field MRI, Leiden University Medical Center, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition, Leiden University, Leiden, the Netherlands
| |
Collapse
|
130
|
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
| |
Collapse
|
131
|
Turner R. Uses, misuses, new uses and fundamental limitations of magnetic resonance imaging in cognitive science. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150349. [PMID: 27574303 PMCID: PMC5003851 DOI: 10.1098/rstb.2015.0349] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2016] [Indexed: 11/29/2022] Open
Abstract
When blood oxygenation level-dependent (BOLD) contrast functional magnetic resonance imaging (fMRI) was discovered in the early 1990s, it provoked an explosion of interest in exploring human cognition, using brain mapping techniques based on MRI. Standards for data acquisition and analysis were rapidly put in place, in order to assist comparison of results across laboratories. Recently, MRI data acquisition capabilities have improved dramatically, inviting a rethink of strategies for relating functional brain activity at the systems level with its neuronal substrates and functional connections. This paper reviews the established capabilities of BOLD contrast fMRI, the perceived weaknesses of major methods of analysis, and current results that may provide insights into improved brain modelling. These results have inspired the use of in vivo myeloarchitecture for localizing brain activity, individual subject analysis without spatial smoothing and mapping of changes in cerebral blood volume instead of BOLD activation changes. The apparent fundamental limitations of all methods based on nuclear magnetic resonance are also discussed.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'.
Collapse
Affiliation(s)
- Robert Turner
- Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1A, 04103 Leipzig, Germany
| |
Collapse
|
132
|
Chatnuntawech I, Martin A, Bilgic B, Setsompop K, Adalsteinsson E, Schiavi E. Vectorial total generalized variation for accelerated multi-channel multi-contrast MRI. Magn Reson Imaging 2016; 34:1161-70. [DOI: 10.1016/j.mri.2016.05.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 05/30/2016] [Indexed: 11/24/2022]
|
133
|
Waszak M, Falkovskiy P, Hilbert T, Bonnier G, Maréchal B, Meuli R, Gruetter R, Kober T, Krueger G. Prospective head motion correction using FID-guided on-demand image navigators. Magn Reson Med 2016; 78:193-203. [DOI: 10.1002/mrm.26364] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 06/19/2016] [Accepted: 07/11/2016] [Indexed: 12/30/2022]
Affiliation(s)
- Maryna Waszak
- Advanced Clinical Imaging Technology (HC CMEA SUI DI BM PI), Siemens Healthcare AG; Lausanne Switzerland
- LTS5, École Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
- Department of Radiology, University Hospital (CHUV); Lausanne Switzerland
| | - Pavel Falkovskiy
- Advanced Clinical Imaging Technology (HC CMEA SUI DI BM PI), Siemens Healthcare AG; Lausanne Switzerland
- LTS5, École Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
- Department of Radiology, University Hospital (CHUV); Lausanne Switzerland
| | - Tom Hilbert
- Advanced Clinical Imaging Technology (HC CMEA SUI DI BM PI), Siemens Healthcare AG; Lausanne Switzerland
- LTS5, École Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
- Department of Radiology, University Hospital (CHUV); Lausanne Switzerland
| | - Guillaume Bonnier
- Advanced Clinical Imaging Technology (HC CMEA SUI DI BM PI), Siemens Healthcare AG; Lausanne Switzerland
- LTS5, École Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
- Department of Radiology, University Hospital (CHUV); Lausanne Switzerland
| | - Bénédicte Maréchal
- Advanced Clinical Imaging Technology (HC CMEA SUI DI BM PI), Siemens Healthcare AG; Lausanne Switzerland
- LTS5, École Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
- Department of Radiology, University Hospital (CHUV); Lausanne Switzerland
| | - Reto Meuli
- Department of Radiology, University Hospital (CHUV); Lausanne Switzerland
| | - Rolf Gruetter
- Department of Radiology, University Hospital (CHUV); Lausanne Switzerland
- Centre d'Imagerie BioMedicale (CIBM), École Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
- Department of Radiology, University of Geneva; Geneva Switzerland
| | - Tobias Kober
- Advanced Clinical Imaging Technology (HC CMEA SUI DI BM PI), Siemens Healthcare AG; Lausanne Switzerland
- LTS5, École Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
- Department of Radiology, University Hospital (CHUV); Lausanne Switzerland
| | - Gunnar Krueger
- LTS5, École Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
- Department of Radiology, University Hospital (CHUV); Lausanne Switzerland
- Siemens Medical Solutions USA, Inc; Boston MA USA
| |
Collapse
|
134
|
Johnson PM, Liu J, Wade T, Tavallaei MA, Drangova M. Retrospective 3D motion correction using spherical navigator echoes. Magn Reson Imaging 2016; 34:1274-1282. [PMID: 27451402 DOI: 10.1016/j.mri.2016.06.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 06/06/2016] [Accepted: 06/26/2016] [Indexed: 10/21/2022]
Abstract
PURPOSE To develop and evaluate a rapid spherical navigator echo (SNAV) motion correction technique, then apply it for retrospective correction of brain images. METHODS The pre-rotated, template matching SNAV method (preRot-SNAV) was developed in combination with a novel hybrid baseline strategy, which includes acquired and interpolated templates. Specifically, the SNAV templates are only rotated around X- and Y-axis; for each rotated SNAV, simulated baseline templates that mimic object rotation about the Z-axis were interpolated. The new method was first evaluated with phantom experiments. Then, a customized SNAV-interleaved gradient echo sequence was used to image three volunteers performing directed head motion. The SNAV motion measurements were used to retrospectively correct the brain images. Experiments were performed using a 3.0T whole-body MRI scanner and both single and 8-channel head coils. RESULTS Phantom rotations and translations measured using the hybrid baselines agreed to within 0.9° and 1mm compared to those measured with the original preRot-SNAV method. Retrospective motion correction of in vivo images using the hybrid preRot-SNAV effectively corrected for head rotation up to 4° and 4mm. CONCLUSIONS The presented hybrid approach enables the acquisition of pre-rotated baseline templates in as little as 2.5s, and results in accurate measurement of rotations and translations. Retrospective 3D motion correction successfully reduced motion artifacts in vivo.
Collapse
Affiliation(s)
- Patricia M Johnson
- Imaging Research Laboratories, Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada; Department of Medical Biophysics, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Junmin Liu
- Imaging Research Laboratories, Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Trevor Wade
- Imaging Research Laboratories, Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Mohammad Ali Tavallaei
- Imaging Research Laboratories, Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada; Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Ontario, Canada
| | - Maria Drangova
- Imaging Research Laboratories, Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada; Department of Medical Biophysics, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada; Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Ontario, Canada.
| |
Collapse
|
135
|
A robust method for suppressing motion-induced coil sensitivity variations during prospective correction of head motion in fMRI. Magn Reson Imaging 2016; 34:1206-19. [PMID: 27451407 DOI: 10.1016/j.mri.2016.06.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 06/13/2016] [Accepted: 06/26/2016] [Indexed: 11/23/2022]
Abstract
Prospective motion correction is a promising candidate solution to suppress the effects of head motion during fMRI, ideally allowing the imaging plane to remain fixed with respect to the moving head. Residual signal artifacts may remain, however, because head motion in relation to a fixed multi-channel receiver coil (with non-uniform sensitivity maps) can potentially introduce unwanted signal variations comparable to the weak fMRI BOLD signal (~1%-4% at 1.5-3.0T). The present work aimed to investigate the magnitude of these residual artifacts, and characterize the regime over which prospective motion correction benefits from adjusting sensitivity maps to reflect relative positional change between the head and the coil. Numerical simulations were used to inform human fMRI experiments. The simulations indicated that for axial imaging within a commonly used 12-channel head coil, 5° of head rotation in-plane produced artifact signal changes of ~3%. Subsequently, six young adults were imaged with and without overt head motions of approximately this extent, with and without prospective motion correction using the Prospective Acquisition CorrEction (PACE) method, and with and without sensitivity map adjustments. Sensitivity map adjustments combined with PACE strongly protected against the artifacts of interest, as indicated by comparing three metrics of data quality (number of activated voxels, Dice coefficient of activation overlap, temporal standard deviation of baseline fMRI timeseries data) across the different experimental conditions. It is concluded that head motion in relation to a fixed multi-channel coil can adversely affect fMRI with prospective motion correction, and that sensitivity map adjustment can mitigate this effect at 3.0T.
Collapse
|
136
|
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
|
137
|
Faraji-Dana Z, Tam F, Chen JJ, Graham SJ. Suppressing Respiration Effects when Geometric Distortion Is Corrected Dynamically by Phase Labeling for Additional Coordinate Encoding (PLACE) during Functional MRI. PLoS One 2016; 11:e0156750. [PMID: 27258194 PMCID: PMC4892595 DOI: 10.1371/journal.pone.0156750] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 03/16/2016] [Indexed: 11/30/2022] Open
Abstract
Echo planar imaging (EPI) suffers from geometric distortions caused by magnetic field inhomogeneities, which can be time-varying as a result of small amounts of head motion that occur over seconds and minutes during fMRI experiments, also known as “dynamic geometric distortion”. Phase Labeling for Additional Coordinate Encoding (PLACE) is a promising technique for geometric distortion correction without reduced temporal resolution and in principle can be used to correct for motion-induced dynamic geometric distortion. PLACE requires at least two EPI images of the same anatomy that are ideally acquired with no variation in the magnetic field inhomogeneities. However, head motion and lung ventilation during the respiratory cycle can cause changes in magnetic field inhomogeneities within the EPI pair used for PLACE. In this work, we exploited dynamic off-resonance in k-space (DORK) and averaging to correct the within EPI pair magnetic field inhomogeneities; and hence proposed a combined technique (DORK+PLACE+averaging) to mitigate dynamic geometric distortion in EPI-based fMRI while preserving the temporal resolution. The performance of the combined DORK, PLACE and averaging technique was characterized through several imaging experiments involving test phantoms and six healthy adult volunteers. Phantom data illustrate reduced temporal standard deviation of fMRI signal intensities after use of combined dynamic PLACE, DORK and averaging compared to the standard processing and static geometric distortion correction. The combined technique also substantially improved the temporal standard deviation and activation maps obtained from human fMRI data in comparison to the results obtained by standard processing and static geometric distortion correction, highlighting the utility of the approach.
Collapse
Affiliation(s)
- Zahra Faraji-Dana
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada
- * E-mail:
| | - Fred Tam
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada
| | - J. Jean Chen
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
- Rotman Research Institute, Baycrest Health Sciences Centre, Toronto, Canada
| | - Simon J. Graham
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada
| |
Collapse
|
138
|
Budinger TF, Bird MD, Frydman L, Long JR, Mareci TH, Rooney WD, Rosen B, Schenck JF, Schepkin VD, Sherry AD, Sodickson DK, Springer CS, Thulborn KR, Uğurbil K, Wald LL. Toward 20 T magnetic resonance for human brain studies: opportunities for discovery and neuroscience rationale. MAGMA (NEW YORK, N.Y.) 2016; 29:617-39. [PMID: 27194154 PMCID: PMC5538368 DOI: 10.1007/s10334-016-0561-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 04/06/2016] [Accepted: 04/11/2016] [Indexed: 12/16/2022]
Abstract
An initiative to design and build magnetic resonance imaging (MRI) and spectroscopy (MRS) instruments at 14 T and beyond to 20 T has been underway since 2012. This initiative has been supported by 22 interested participants from the USA and Europe, of which 15 are authors of this review. Advances in high temperature superconductor materials, advances in cryocooling engineering, prospects for non-persistent mode stable magnets, and experiences gained from large-bore, high-field magnet engineering for the nuclear fusion endeavors support the feasibility of a human brain MRI and MRS system with 1 ppm homogeneity over at least a 16-cm diameter volume and a bore size of 68 cm. Twelve neuroscience opportunities are presented as well as an analysis of the biophysical and physiological effects to be investigated before exposing human subjects to the high fields of 14 T and beyond.
Collapse
Affiliation(s)
- Thomas F Budinger
- Lawrence Berkeley National Laboratory, University of California, Berkeley, CA, USA.
| | - Mark D Bird
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
| | - Lucio Frydman
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
- Weizmann Institute, Rehovot, Israel
| | - Joanna R Long
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Thomas H Mareci
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | | | - Bruce Rosen
- Massachusetts General Hospital, Harvard Medical School, Harvard, MA, USA
| | - John F Schenck
- General Electric Corporate Research, Schenectady, NY, USA
| | - Victor D Schepkin
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
| | - A Dean Sherry
- University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | | | | | | | - Lawrence L Wald
- Massachusetts General Hospital, Harvard Medical School, Harvard, MA, USA
| |
Collapse
|
139
|
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.
Collapse
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
| |
Collapse
|
140
|
Alexander-Bloch A, Clasen L, Stockman M, Ronan L, Lalonde F, Giedd J, Raznahan A. Subtle in-scanner motion biases automated measurement of brain anatomy from in vivo MRI. Hum Brain Mapp 2016; 37:2385-97. [PMID: 27004471 DOI: 10.1002/hbm.23180] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 02/29/2016] [Accepted: 03/01/2016] [Indexed: 11/07/2022] Open
Abstract
While the potential for small amounts of motion in functional magnetic resonance imaging (fMRI) scans to bias the results of functional neuroimaging studies is well appreciated, the impact of in-scanner motion on morphological analysis of structural MRI is relatively under-studied. Even among "good quality" structural scans, there may be systematic effects of motion on measures of brain morphometry. In the present study, the subjects' tendency to move during fMRI scans, acquired in the same scanning sessions as their structural scans, yielded a reliable, continuous estimate of in-scanner motion. Using this approach within a sample of 127 children, adolescents, and young adults, significant relationships were found between this measure and estimates of cortical gray matter volume and mean curvature, as well as trend-level relationships with cortical thickness. Specifically, cortical volume and thickness decreased with greater motion, and mean curvature increased. These effects of subtle motion were anatomically heterogeneous, were present across different automated imaging pipelines, showed convergent validity with effects of frank motion assessed in a separate sample of 274 scans, and could be demonstrated in both pediatric and adult populations. Thus, using different motion assays in two large non-overlapping sets of structural MRI scans, convergent evidence showed that in-scanner motion-even at levels which do not manifest in visible motion artifact-can lead to systematic and regionally specific biases in anatomical estimation. These findings have special relevance to structural neuroimaging in developmental and clinical datasets, and inform ongoing efforts to optimize neuroanatomical analysis of existing and future structural MRI datasets in non-sedated humans. Hum Brain Mapp 37:2385-2397, 2016. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Aaron Alexander-Bloch
- Developmental Neurogenomics Unit, Child Psychiatry Branch, National Institute of Mental Health, Bethesda, Maryland.,Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Liv Clasen
- Developmental Neurogenomics Unit, Child Psychiatry Branch, National Institute of Mental Health, Bethesda, Maryland
| | - Michael Stockman
- Developmental Neurogenomics Unit, Child Psychiatry Branch, National Institute of Mental Health, Bethesda, Maryland
| | - Lisa Ronan
- Brain Mapping Unit, University of Cambridge, Cambridge, United Kingdom
| | - Francois Lalonde
- Developmental Neurogenomics Unit, Child Psychiatry Branch, National Institute of Mental Health, Bethesda, Maryland
| | - Jay Giedd
- Department of Psychiatry, UCSD, San Diego, California
| | - Armin Raznahan
- Developmental Neurogenomics Unit, Child Psychiatry Branch, National Institute of Mental Health, Bethesda, Maryland
| |
Collapse
|
141
|
Lorio S, Kherif F, Ruef A, Melie-Garcia L, Frackowiak R, Ashburner J, Helms G, Lutti A, Draganski B. Neurobiological origin of spurious brain morphological changes: A quantitative MRI study. Hum Brain Mapp 2016; 37:1801-15. [PMID: 26876452 PMCID: PMC4855623 DOI: 10.1002/hbm.23137] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 01/18/2016] [Accepted: 01/26/2016] [Indexed: 01/04/2023] Open
Abstract
The high gray‐white matter contrast and spatial resolution provided by T1‐weighted magnetic resonance imaging (MRI) has made it a widely used imaging protocol for computational anatomy studies of the brain. While the image intensity in T1‐weighted images is predominantly driven by T1, other MRI parameters affect the image contrast, and hence brain morphological measures derived from the data. Because MRI parameters are correlates of different histological properties of brain tissue, this mixed contribution hampers the neurobiological interpretation of morphometry findings, an issue which remains largely ignored in the community. We acquired quantitative maps of the MRI parameters that determine signal intensities in T1‐weighted images (R1 (=1/T1), R2*, and PD) in a large cohort of healthy subjects (n = 120, aged 18–87 years). Synthetic T1‐weighted images were calculated from these quantitative maps and used to extract morphometry features—gray matter volume and cortical thickness. We observed significant variations in morphometry measures obtained from synthetic images derived from different subsets of MRI parameters. We also detected a modulation of these variations by age. Our findings highlight the impact of microstructural properties of brain tissue—myelination, iron, and water content—on automated measures of brain morphology and show that microstructural tissue changes might lead to the detection of spurious morphological changes in computational anatomy studies. They motivate a review of previous morphological results obtained from standard anatomical MRI images and highlight the value of quantitative MRI data for the inference of microscopic tissue changes in the healthy and diseased brain. Hum Brain Mapp 37:1801–1815, 2016. © 2016 The Authors. Human Brain Mapping Published by Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Sara Lorio
- LREN - Department of Clinical Neurosciences, CHUV, University of Lausanne, Lausanne Switzerland
| | - Ferath Kherif
- LREN - Department of Clinical Neurosciences, CHUV, University of Lausanne, Lausanne Switzerland
| | - Anne Ruef
- LREN - Department of Clinical Neurosciences, CHUV, University of Lausanne, Lausanne Switzerland
| | - Lester Melie-Garcia
- LREN - Department of Clinical Neurosciences, CHUV, University of Lausanne, Lausanne Switzerland
| | - Richard Frackowiak
- LREN - Department of Clinical Neurosciences, CHUV, University of Lausanne, Lausanne Switzerland
| | - John Ashburner
- Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, UCL, London, United Kingdom
| | - Gunther Helms
- Department of Clinical Sciences, Lund University, Medical Radiation Physics, Lund, Sweden
| | - Antoine Lutti
- LREN - Department of Clinical Neurosciences, CHUV, University of Lausanne, Lausanne Switzerland
| | - Bodgan Draganski
- LREN - Department of Clinical Neurosciences, CHUV, University of Lausanne, Lausanne Switzerland.,Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| |
Collapse
|
142
|
Gallichan D, Marques JP. Optimizing the acceleration and resolution of three-dimensional fat image navigators for high-resolution motion correction at 7T. Magn Reson Med 2016; 77:547-558. [PMID: 26877158 DOI: 10.1002/mrm.26127] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 12/01/2015] [Accepted: 12/22/2015] [Indexed: 11/07/2022]
Abstract
PURPOSE To investigate the effect of spatial resolution and parallel imaging acceleration factor on the quality of the motion estimates derived from image navigators with a three-dimensional (3D) gradient-recalled echo (GRE) acquisition with fat excitation (3D FatNavs) for neuroimaging at 7T. METHODS Six healthy subjects were scanned for 10 min, during which time repeated GRE volumes were acquired during small movements-alternating between fat and water excitations (WaterNavs)-allowing retrospective decimation of the data to simulate a variety of combinations of image resolution and acceleration factor. Bias and error in the motion estimates were then compared across navigator parameters. RESULTS The 2-mm, 4 × 4 accelerated data (TRvolume = 1.2 s) provided motion estimates that were almost indistinguishable from those from the full original acquisition (2 mm, 2 × 2, TRvolume = 5.2 s). For faster navigators, it was found that good accuracy and precision were achievable with TRvolume = 144 ms, using a lower spatial resolution (4 mm, 6 × 6 acceleration) to avoid the bias observed at exceptionally high acceleration factors (8 × 8 or higher). Parameter estimates from WaterNavs and FatNavs showed close agreement with FatNavs, with better performance at exceptionally high acceleration factors. CONCLUSION Our data help to guide the parameter choice for 3D FatNavs when a compromise must be reached between the quality of the motion estimates and the available scan time. Magn Reson Med 77:547-558, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
| | - José P Marques
- CIBM, EPFL Lausanne, Switzerland
- Donders Center for Cognitive Neuroimaging, Radboud University, Netherlands
| |
Collapse
|
143
|
Hale J, Hamilton AFDC. Cognitive mechanisms for responding to mimicry from others. Neurosci Biobehav Rev 2016; 63:106-23. [PMID: 26877104 DOI: 10.1016/j.neubiorev.2016.02.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 01/04/2016] [Accepted: 02/08/2016] [Indexed: 12/30/2022]
Abstract
Compared to our understanding of neurocognitive processes involved producing mimicry, the downstream consequences of being mimicked are less clear. A wide variety of positive consequences of mimicry, such as liking and helping, have been reported in behavioural research. However, an in-depth review suggests the link from mimicry to liking and other positive outcomes may be fragile. Positive responses to mimicry can break down due to individual factors and social situations where mimicry may be unexpected. It remains unclear how the complex behavioural effects of mimicry relate to neural systems which respond to being mimicked. Mimicry activates regions associated with mirror properties, self-other processing and reward. In this review, we outline three potential models linking these regions with cognitive consequences of being mimicked. The models suggest that positive downstream consequences of mimicry may depend upon self-other overlap, detection of contingency or low prediction error. Finally, we highlight limitations with traditional research designs and suggest alternative methods for achieving highly ecological validity and experimental control. We also highlight unanswered questions which may guide future research.
Collapse
Affiliation(s)
- Joanna Hale
- UCL Institute of Cognitive Neuroscience, Alexandra House, 17 Queen Square, London WC1N 3AR, UK.
| | - Antonia F de C Hamilton
- UCL Institute of Cognitive Neuroscience, Alexandra House, 17 Queen Square, London WC1N 3AR, UK.
| |
Collapse
|
144
|
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.
Collapse
Affiliation(s)
- F Godenschweger
- Biomedical Magnetic Resonance, Otto-von-Guericke University, Magdeburg, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
145
|
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.
Collapse
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
| |
Collapse
|
146
|
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.
Collapse
Affiliation(s)
- Thomas Lange
- Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany
| | | | | | | | | | | |
Collapse
|
147
|
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.
Collapse
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
| |
Collapse
|
148
|
Frost R, Hess AT, Okell TW, Chappell MA, Tisdall MD, van der Kouwe AJW, Jezzard P. Prospective motion correction and selective reacquisition using volumetric navigators for vessel-encoded arterial spin labeling dynamic angiography. Magn Reson Med 2015; 76:1420-1430. [PMID: 26567122 DOI: 10.1002/mrm.26040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 10/14/2015] [Accepted: 10/17/2015] [Indexed: 11/06/2022]
Abstract
PURPOSE The aim of this study was to improve robustness to motion in a vessel-encoded angiography sequence used for patient scans. The sequence is particularly sensitive to motion between imaging segments, which causes ghosting and blurring that propagates to the final angiogram. METHODS Volumetric echo planar imaging (EPI) navigators acquired in 275 ms were inserted after the imaging readout in a vessel-encoded pseudo-continuous arterial spin labeling (VEPCASL) sequence. The effects of movement between segments on the images were tested with phantom experiments. Deliberate motion experiments with healthy volunteers were performed to compare prospective motion correction (PMC) with reacquisition versus no correction. RESULTS In scans without motion, the addition of the EPI navigator to the sequence did not affect the quality of the angiograms in comparison with the original sequence. PMC and reacquisition improved the visibility of vessels in the angiograms compared with the scans without correction. The reacquisition strategy was shown to be important for complete correction of imaging artifacts. CONCLUSION We have demonstrated an effective method to correct motion in vessel-encoded angiography. For reacquisition of 15 segments, the technique requires approximately 30 s of additional scanning (∼25%). Magn Reson Med 76:1420-1430, 2016. © 2015 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Robert Frost
- FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
| | - Aaron T Hess
- Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Thomas W Okell
- FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Michael A Chappell
- FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - M Dylan Tisdall
- A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.,Department of Radiology, Harvard Medical School, Boston, Massachusetts, USA
| | - André J W van der Kouwe
- A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.,Department of Radiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Peter Jezzard
- FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
149
|
Zahneisen B, Assländer J, LeVan P, Hugger T, Reisert M, Ernst T, Hennig J. Quantification and correction of respiration induced dynamic field map changes in fMRI using 3D single shot techniques. Magn Reson Med 2015; 71:1093-102. [PMID: 23716298 DOI: 10.1002/mrm.24771] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
PURPOSE Respiration induced dynamic field map changes in the brain are quantified and the influence on the magnitude signal (physiological noise) is investigated. Dynamic off-resonance correction allows to reduce the signal fluctuations overlaying the blood oxygenation level dependent signal in T2*-weighted functional imaging. THEORY AND METHODS A single-shot whole brain imaging technique with 100 ms temporal resolution was used to measure dynamic off-resonance maps that were calculated from the incremental changes of the image phase. These off-resonance maps are then used to dynamically update the off-resonance corrected reconstruction. RESULTS A global resonance offset and a pronounced gradient in head-foot direction were identified as the main components of the change during a respiration cycle. On average, correction for these fluctuations decreases the magnitude fluctuations by around 30%. CONCLUSION Single shot 3D imaging allows for a robust quantification of dynamic off-resonance changes in the brain. Correction for these fluctuations removes the physiological noise component associated with dynamic point spread function changes.
Collapse
Affiliation(s)
- Benjamin Zahneisen
- Department of Medicine, University of Hawaii, John A. Burns School of Medicine, Honolulu, Hawaii, USA
| | | | | | | | | | | | | |
Collapse
|
150
|
Nunes RG, Malik SJ, Hajnal JV. Single shot fast spin echo diffusion imaging with correction for non-linear phase errors using tailored RF pulses. Magn Reson Med 2015; 71:691-701. [PMID: 23463486 DOI: 10.1002/mrm.24711] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
PURPOSE The use of tailored RF excitation pulses for prospective correction of non-linear motion-induced phase patterns is shown to enable diffusion-weighted (DW) fast spin echo (FSE) imaging in vivo. Echo-planar imaging (EPI) remains the most used sequence for DW imaging. Despite being highly sensitive to field inhomogeneities, EPI is robust to motion-induced phase shifts. FSE sequences are much less sensitive to field inhomogeneities, but require precise control of the transverse magnetization phase, which is hard to achieve with DW. Real time measurements and correction of phase ramps due to rigid-body motion had been proposed, but performance remained unsatisfactory because of non-linear phase patterns related to pulsatile motion. METHODS Reproducible non-linear phase components are calibrated using 2D-EPI navigators and tailored RF excitation pulses designed. Real time correction of rigid-body motion was not yet implemented. RESULTS Phase correction was confirmed with full signal DW-FSE images obtained on co-operative subjects. Full diffusion tensor acquisitions were obtained and color-coded maps displaying principal fiber directionality calculated. Results were consistent with corresponding EPI acquisitions except for absence of spatial distortions. CONCLUSION Combining the proposed method with real time compensation of rigid-body motion has the potential to allow high quality, distortion free diffusion imaging throughout the brain.
Collapse
Affiliation(s)
- Rita G Nunes
- Institute of Biophysics and Biomedical Engineering, Faculty of Sciences, University of Lisbon, Lisbon, Portugal; Robert Steiner MRI Unit, Department of Imaging Sciences, Hammersmith Hospital Campus, Imperial College London, UK; Division of Imaging Sciences and Biomedical Engineering, Center for the Developing Brain, King's College London, UK
| | | | | |
Collapse
|