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Huang Y, Chen L, Li X, Liu J. Improved test-retest reliability of R 2 * $$ {\mathrm{R}}_2^{\ast } $$ and susceptibility quantification using multishot multi-echo 3D EPI. Magn Reson Med 2024; 91:2310-2319. [PMID: 38156825 PMCID: PMC10997481 DOI: 10.1002/mrm.29992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 12/07/2023] [Accepted: 12/12/2023] [Indexed: 01/03/2024]
Abstract
PURPOSE This study aimed to evaluate the potential of 3D EPI for improving the reliability ofT 2 * $$ {\mathrm{T}}_2^{\ast } $$ -weighted data and quantification ofR 2 * $$ {\mathrm{R}}_2^{\ast } $$ decay rate and susceptibility (χ) compared with conventional gradient-echo (GRE)-based acquisition. METHODS Eight healthy subjects in a wide age range were recruited. Each subject received repeated scans for both GRE and EPI acquisitions with an isotropic 1 mm resolution at 3 T. Maps ofR 2 * $$ {\mathrm{R}}_2^{\ast } $$ and χ were quantified, and their interscan differences were used to evaluate the test-retest reliability. Interprotocol differences ofR 2 * $$ {\mathrm{R}}_2^{\ast } $$ and χ between GRE and EPI were also measured voxel by voxel and in selected regions of interest to test the consistency between the two acquisition methods. RESULTS The quantifications ofR 2 * $$ {\mathrm{R}}_2^{\ast } $$ and χ using EPI protocols showed increased test-retest reliability with higher EPI factors up to 5 as performed in the experiment and were consistent with those based on GRE. CONCLUSION The result suggests that multishot multi-echo 3D EPI can be a useful alternative acquisition method forT 2 * $$ {\mathrm{T}}_2^{\ast } $$ -weighted MRI and quantification ofR 2 * $$ {\mathrm{R}}_2^{\ast } $$ and χ with reduced scan time, improved test-retest reliability, and similar accuracy compared with commonly used 3D GRE.
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Affiliation(s)
- Yujia Huang
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, USA
| | - Lin Chen
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Department of Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Xu Li
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Department of Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Jiaen Liu
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, USA
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA
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2
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Sun K, Chen Z, Dan G, Luo Q, Yan L, Liu F, Zhou XJ. Three-dimensional echo-shifted EPI with simultaneous blip-up and blip-down acquisitions for correcting geometric distortion. Magn Reson Med 2023; 90:2375-2387. [PMID: 37667533 PMCID: PMC10903279 DOI: 10.1002/mrm.29828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 07/08/2023] [Accepted: 07/25/2023] [Indexed: 09/06/2023]
Abstract
PURPOSE EPI with blip-up/down acquisition (BUDA) can provide high-quality images with minimal distortions by using two readout trains with opposing phase-encoding gradients. Because of the need for two separate acquisitions, BUDA doubles the scan time and degrades the temporal resolution when compared to single-shot EPI, presenting a major challenge for many applications, particularly fMRI. This study aims at overcoming this challenge by developing an echo-shifted EPI BUDA (esEPI-BUDA) technique to acquire both blip-up and blip-down datasets in a single shot. METHODS A 3D esEPI-BUDA pulse sequence was designed by using an echo-shifting strategy to produce two EPI readout trains. These readout trains produced a pair of k-space datasets whose k-space trajectories were interleaved with opposite phase-encoding gradient directions. The two k-space datasets were separately reconstructed using a 3D SENSE algorithm, from which time-resolved B0 -field maps were derived using TOPUP in FSL and then input into a forward model of joint parallel imaging reconstruction to correct for geometric distortion. In addition, Hankel structured low-rank constraint was incorporated into the reconstruction framework to improve image quality by mitigating the phase errors between the two interleaved k-space datasets. RESULTS The 3D esEPI-BUDA technique was demonstrated in a phantom and an fMRI study on healthy human subjects. Geometric distortions were effectively corrected in both phantom and human brain images. In the fMRI study, the visual activation volumes and their BOLD responses were comparable to those from conventional 3D echo-planar images. CONCLUSION The improved imaging efficiency and dynamic distortion correction capability afforded by 3D esEPI-BUDA are expected to benefit many EPI applications.
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Affiliation(s)
- Kaibao Sun
- Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, IL, United States
| | - Zhifeng Chen
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- Department of Data Science and AI, Faculty of IT, Monash University, Clayton, VIC, Australia
| | - Guangyu Dan
- Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, IL, United States
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, United States
| | - Qingfei Luo
- Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, IL, United States
| | - Lirong Yan
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Feng Liu
- School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, Queensland, Australia
| | - Xiaohong Joe Zhou
- Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, IL, United States
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, United States
- Departments of Radiology and Neurosurgery, University of Illinois at Chicago, Chicago, IL, United States
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Huang Y, Chen L, Li X, Liu J. Improved test-retest reliability of R2* and susceptibility quantification using multi-shot multi-echo 3D EPI. ArXiv 2023:arXiv:2308.07811v1. [PMID: 37645047 PMCID: PMC10462177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
This study aimed to evaluate the potential of 3D echo-planar imaging (EPI) for improving the reliability of T2*-weighted (T2*w) data and quantification of R2* decay rate and susceptibility (χ) compared to conventional gradient echo (GRE)-based acquisition. Eight healthy subjects in a wide age range were recruited. Each subject received repeated scans for both GRE and EPI acquisitions with an isotropic 1 mm resolution at 3 T. Maps of R2* and χ were quantified and compared using their inter-scan difference to evaluate the test-retest reliability. Inter-protocol differences of R2* and χ between GRE and EPI were also measured voxel by voxel and in selected ROIs to test the consistency between the two acquisition methods. The quantifications of R2* and χ using EPI protocols showed increased test-retest reliability with higher EPI factors up to 5 as performed in the experiment and were consistent with those based on GRE. This result suggested multi-shot multi-echo 3D EPI can be a useful alternative acquisition method for T2*w MRI and quantification of R2* and χ with reduced scan time, improved test-retest reliability and similar accuracy compared to commonly used 3D GRE.
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Affiliation(s)
- Yujia Huang
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, USA
| | - Lin Chen
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Department of Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Xu Li
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Department of Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Jiaen Liu
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, USA
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA
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Priovoulos N, Roos T, Ipek Ö, Meliado EF, Nkrumah RO, Klomp DWJ, van der Zwaag W. A local multi-transmit coil combined with a high-density receive array for cerebellar fMRI at 7 T. NMR Biomed 2021; 34:e4586. [PMID: 34231292 PMCID: PMC8519055 DOI: 10.1002/nbm.4586] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 06/09/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
The human cerebellum is involved in a wide array of functions, ranging from motor control to cognitive control, and as such is of great neuroscientific interest. However, its function is underexplored in vivo, due to its small size, its dense structure and its placement at the bottom of the brain, where transmit and receive fields are suboptimal. In this study, we combined two dense coil arrays of 16 small surface receive elements each with a transmit array of three antenna elements to improve BOLD sensitivity in the human cerebellum at 7 T. Our results showed improved B1+ and SNR close to the surface as well as g-factor gains compared with a commercial coil designed for whole-head imaging. This resulted in improved signal stability and large gains in the spatial extent of the activation close to the surface (<3.5 cm), while good performance was retained deeper in the cerebellum. Modulating the phase of the transmit elements of the head coil to constructively interfere in the cerebellum improved the B1+ , resulting in a temporal SNR gain. Overall, our results show that a dedicated transmit array along with the SNR gains of surface coil arrays can improve cerebellar imaging, at the cost of a decreased field of view and increased signal inhomogeneity.
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Affiliation(s)
- Nikos Priovoulos
- Spinoza Center for NeuroimagingRoyal Netherlands Academy of Arts and Sciences (KNAW)AmsterdamThe Netherlands
| | - Thomas Roos
- Spinoza Center for NeuroimagingRoyal Netherlands Academy of Arts and Sciences (KNAW)AmsterdamThe Netherlands
| | - Özlem Ipek
- Department of Biomedical Engineering, School of Biomedical Engineering & Imaging SciencesKing's College LondonLondonUK
| | - Ettore F. Meliado
- Image Sciences InstituteUniversity Medical Center UtrechtUtrechtNetherlands
| | - Richard O. Nkrumah
- Department of Biomedical Engineering, School of Biomedical Engineering & Imaging SciencesKing's College LondonLondonUK
| | - Dennis W. J. Klomp
- Image Sciences InstituteUniversity Medical Center UtrechtUtrechtNetherlands
| | - Wietske van der Zwaag
- Spinoza Center for NeuroimagingRoyal Netherlands Academy of Arts and Sciences (KNAW)AmsterdamThe Netherlands
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Hendriks AD, D'Agata F, Raimondo L, Schakel T, Geerts L, Luijten PR, Klomp DW, Petridou N. Pushing functional MRI spatial and temporal resolution further: High-density receive arrays combined with shot-selective 2D CAIPIRINHA for 3D echo-planar imaging at 7 T. NMR Biomed 2020; 33:e4281. [PMID: 32128898 PMCID: PMC7187278 DOI: 10.1002/nbm.4281] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 01/31/2020] [Accepted: 02/05/2020] [Indexed: 05/04/2023]
Abstract
To be able to examine dynamic and detailed brain functions, the spatial and temporal resolution of 7 T MRI needs to improve. In this study, it was investigated whether submillimeter multishot 3D EPI fMRI scans, acquired with high-density receive arrays, can benefit from a 2D CAIPIRINHA sampling pattern, in terms of noise amplification (g-factor), temporal SNR and fMRI sensitivity. High-density receive arrays were combined with a shot-selective 2D CAIPIRINHA implementation for multishot 3D EPI sequences at 7 T. In this implementation, in contrast to conventional inclusion of extra kz gradient blips, specific EPI shots are left out to create a CAIPIRINHA shift and reduction of scan time. First, the implementation of the CAIPIRINHA sequence was evaluated with a standard receive setup by acquiring submillimeter whole brain T2 *-weighted anatomy images. Second, the CAIPIRINHA sequence was combined with high-density receive arrays to push the temporal resolution of submillimeter 3D EPI fMRI scans of the visual cortex. Results show that the shot-selective 2D CAIPIRINHA sequence enables a reduction in scan time for 0.5 mm isotropic 3D EPI T2 *-weighted anatomy scans by a factor of 4 compared with earlier reports. The use of the 2D CAIPIRINHA implementation in combination with high-density receive arrays, enhances the image quality of submillimeter 3D EPI scans of the visual cortex at high acceleration as compared to conventional SENSE. Both the g-factor and temporal SNR improved, resulting in a method that is more sensitive to the fMRI signal. Using this method, it is possible to acquire submillimeter single volume 3D EPI scans of the visual cortex in a subsecond timeframe. Overall, high-density receive arrays in combination with shot-selective 2D CAIPIRINHA for 3D EPI scans prove to be valuable for reducing the scan time of submillimeter MRI acquisitions.
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Affiliation(s)
- Arjan D. Hendriks
- Department of RadiologyCenter for Image Sciences, University Medical Center UtrechtUtrechtthe Netherlands
| | - Federico D'Agata
- Department of RadiologyCenter for Image Sciences, University Medical Center UtrechtUtrechtthe Netherlands
- Department of NeuroscienceUniversity of TurinTurinItaly
| | - Luisa Raimondo
- Department of RadiologyCenter for Image Sciences, University Medical Center UtrechtUtrechtthe Netherlands
- Spinoza Centre for NeuroimagingAmsterdamthe Netherlands
| | - Tim Schakel
- Department of RadiologyCenter for Image Sciences, University Medical Center UtrechtUtrechtthe Netherlands
| | | | - Peter R. Luijten
- Department of RadiologyCenter for Image Sciences, University Medical Center UtrechtUtrechtthe Netherlands
| | - Dennis W.J. Klomp
- Department of RadiologyCenter for Image Sciences, University Medical Center UtrechtUtrechtthe Netherlands
| | - Natalia Petridou
- Department of RadiologyCenter for Image Sciences, University Medical Center UtrechtUtrechtthe Netherlands
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Moeller S, Ramanna S, Lenglet C, Pisharady PK, Auerbach EJ, Delabarre L, Wu X, Akcakaya M, Ugurbil K. Self-navigation for 3D multishot EPI with data-reference. Magn Reson Med 2020; 84:1747-1762. [PMID: 32115756 DOI: 10.1002/mrm.28231] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 02/01/2020] [Accepted: 02/04/2020] [Indexed: 02/03/2023]
Abstract
PURPOSE In this study, we sought to develop a self-navigation strategy for improving the reconstruction of diffusion weighted 3D multishot echo planar imaging (EPI). We propose a method for extracting the phase correction information from the acquisition itself, eliminating the need for a 2D navigator, further accelerating the acquisition. METHODS In-vivo acquisitions at 3T with 0.9 mm and 1.5 mm isotropic resolutions were used to evaluate the performance of the self-navigation strategy. Sensitivity to motion was tested using a large difference in pitch position of the head. Using a multishell diffusion weighted acquisition, tractography results were obtained at (0.9 mm)3 to validate the quality with conventional acquisition. RESULTS The use of 3D multislab EPI with self-navigation enables 3D diffusion-weighted spin echo EPI acquisitions that have the same efficiency as 2D single-shot acquisition. For matched acquisition time the image signal-to-noise ratio (SNR) between 3D and 2D acquisition is shown to be comparable for whole-brain coverage with (1.5 mm)3 resolution and for (0.9 mm)3 resolution the 3D acquisition has higher SNR than what can be obtained with 2D acquisitions using current state-of-art multiband techniques. The self-navigation technique was shown to be stable under inter-volume motion. In tractography analysis, the higher resolution afforded by our technique enabled clear delineation of the tapetum and posterior corona radiata. CONCLUSION The proposed self-navigation approach utilized a self-consistent phase in 3D diffusion weighted acquisitions. Its efficiency and stability were demonstrated for a plurality of common acquisitions. The proposed self-navigation approach allows for faster acquisition of 3D multishot EPI desirable for large field of view and/or higher resolution.
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Affiliation(s)
- Steen Moeller
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, USA.,Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Sudhir Ramanna
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, USA.,Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Christophe Lenglet
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, USA.,Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Pramod K Pisharady
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, USA.,Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Edward J Auerbach
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, USA.,Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Lance Delabarre
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, USA.,Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Xiaoping Wu
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, USA.,Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Mehmet Akcakaya
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, USA.,Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Kamil Ugurbil
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, USA.,Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, USA
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Gai ND, Butman JA. Determining the optimal postlabeling delay for arterial spin labeling using subject-specific estimates of blood velocity in the carotid artery. J Magn Reson Imaging 2019; 50:951-960. [PMID: 30681220 DOI: 10.1002/jmri.26670] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 01/11/2019] [Accepted: 01/14/2019] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Arterial spin labeling with 3D acquisition requires determining a single postlabeling delay (PLD) value. PLD affects the signal-to-noise ratio (SNR) per unit time as well as quantitative cerebral blood flow (CBF) values due to its bearing on the presence of a vascular signal. PURPOSE To search for an optimal PLD for pseudocontinuous arterial spin labeling (pCASL) using patient-specific carotid artery blood velocity measurements. STUDY TYPE Prospective. SUBJECTS A control group of 11 volunteers with no known pathology. Corroboration was through a separate group of six volunteers and a noncontrol group of five sickle cell disease (SCD) patients. FIELD STRENGTH/SEQUENCE Pseudocontinuous arterial spin labeling with 3D nonsegmented echo planar imaging acquisition at 3T. ASSESSMENT A perfusion-based measure was determined over a range of PLDs for each of 11 volunteers. A third-order polynomial was used to find the optimal PLD where the defined measure was maximum. This was plotted against the corresponding carotid artery velocity to determine a relationship between the perfusion measure and velocity. Corroboration was done using a group of six volunteers and a noncontrol group of five patients with SCD. PLD was determined from the carotid artery velocity and derived relationship and compared with optimal PLD obtained from measured perfusion over a range of PLD values. Error between the perfusion measure at predicted and measured optimal PLD was determined. STATISTICAL TESTS Chi-squared goodness of fit; Pearson correlation; Bland-Altman. RESULTS Carotid artery velocity was 63.8 ± 6.6 cm/s (53.1 ≤ v ≤ 72.3 cm/s) while optimal PLD was 1374 ± 226.5 msec (1102 ≤ PLD ≤ 1787 msec) across the 11 volunteers. PLD as a function of carotid velocity was determined to be PLD = -31.94. v + 3410 msec (Pearson correlation -0.93). In six volunteers, mean error between the perfusion measure at predicted and measured optimal PLD was 1.35%. Pearson correlation between the perfusion measure at the predicted PLD and the measure obtained experimentally was r = 0.96 (P < 0.001). Bland-Altman revealed a slight bias of 1.3%. For the test case of five SCD patients, the mean error was 1.3%. DATA CONCLUSION Carotid artery velocity was used to determine optimal PLD for pCASL with 3D acquisition. The derived relationship was used to predict optimal PLD and the associated perfusion measure, which was found to be accurate when compared with its measured counterpart. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;50:951-960.
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Affiliation(s)
- Neville D Gai
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - John A Butman
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
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Reynaud O, Jorge J, Gruetter R, Marques JP, van der Zwaag W. Influence of physiological noise on accelerated 2D and 3D resting state functional MRI data at 7 T. Magn Reson Med 2017; 78:888-896. [PMID: 28686788 DOI: 10.1002/mrm.26823] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 06/06/2017] [Accepted: 06/13/2017] [Indexed: 12/28/2022]
Abstract
PURPOSE Physiological noise often dominates the blood-oxygen level-dependent (BOLD) signal fluctuations in high-field functional MRI (fMRI) data. Therefore, to optimize fMRI protocols, it becomes crucial to investigate how physiological signal fluctuations impact various acquisition and reconstruction schemes at different acquisition speeds. In particular, further differences can arise between 2D and 3D fMRI acquisitions due to different encoding strategies, thereby impacting fMRI sensitivity in potentially significant ways. METHODS The amount of physiological noise to be removed from the BOLD fMRI signal acquired at 7 T was quantified for different sampling rates (repetition time from 3300 to 350 ms, acceleration 1 to 8) and techniques dedicated to fast fMRI (simultaneous multislice echo planar imaging [EPI] and 3D EPI). Resting state fMRI (rsfMRI) performances were evaluated using temporal signal-to-noise ratio (tSNR) and network characterization based on seed correlation and independent component analysis. RESULTS Overall, acceleration enhanced tSNR and rsfMRI metrics. 3D EPI benefited the most from physiological noise removal at long repetition times. Differences between 2D and 3D encoding strategies disappeared at high acceleration factors (6- to 8-fold). CONCLUSION After physiological noise correction, 2D- and 3D-accelerated sequences provide similar performances at high fields, both in terms of tSNR and resting state network identification and characterization. Magn Reson Med 78:888-896, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Olivier Reynaud
- Centre d'Imagerie Biomédicale, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - João Jorge
- Laboratoire for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Rolf Gruetter
- Centre d'Imagerie Biomédicale, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Laboratoire for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Department of Radiology, University of Geneva, Geneva, Switzerland.,Department of Radiology, University of Lausanne, Lausanne, Switzerland
| | - José P Marques
- Centre d'Imagerie Biomédicale, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Donders Institute for Brain Behaviour and Cognition, Nijmegen, Netherlands
| | - Wietske van der Zwaag
- Centre d'Imagerie Biomédicale, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Spinoza Centre for Neuroimaging, Amsterdam, Netherlands
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9
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Graedel NN, McNab JA, Chiew M, Miller KL. Motion correction for functional MRI with three-dimensional hybrid radial-Cartesian EPI. Magn Reson Med 2016; 78:527-540. [PMID: 27604503 PMCID: PMC5516130 DOI: 10.1002/mrm.26390] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Revised: 07/26/2016] [Accepted: 07/27/2016] [Indexed: 11/13/2022]
Abstract
Purpose Subject motion is a major source of image degradation for functional MRI (fMRI), especially when using multishot sequences like three‐dimensional (3D EPI). We present a hybrid radial‐Cartesian 3D EPI trajectory enabling motion correction in k‐space for functional MRI. Methods The EPI “blades” of the 3D hybrid radial‐Cartesian EPI sequence, called TURBINE, are rotated about the phase‐encoding axis to fill out a cylinder in 3D k‐space. Angular blades are acquired over time using a golden‐angle rotation increment, allowing reconstruction at flexible temporal resolution. The self‐navigating properties of the sequence are used to determine motion parameters from a high temporal‐resolution navigator time series. The motion is corrected in k‐space as part of the image reconstruction, and evaluated for experiments with both cued and natural motion. Results We demonstrate that the motion correction works robustly and that we can achieve substantial artifact reduction as well as improvement in temporal signal‐to‐noise ratio and fMRI activation in the presence of both severe and subtle motion. Conclusion We show the potential for hybrid radial‐Cartesian 3D EPI to substantially reduce artifacts for application in fMRI, especially for subject groups with significant head motion. The motion correction approach does not prolong the scan, and no extra hardware is required. Magn Reson Med 78:527–540, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
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Affiliation(s)
- Nadine N Graedel
- FMRIB Centre for Functional MRI of the Brain, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Jennifer A McNab
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Mark Chiew
- FMRIB Centre for Functional MRI of the Brain, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Karla L Miller
- FMRIB Centre for Functional MRI of the Brain, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
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Tse DHY, Wiggins CJ, Ivanov D, Brenner D, Hoffmann J, Mirkes C, Shajan G, Scheffler K, Uludağ K, Poser BA. Volumetric imaging with homogenised excitation and static field at 9.4 T. MAGMA 2016; 29:333-45. [PMID: 26995492 PMCID: PMC4891373 DOI: 10.1007/s10334-016-0543-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 02/26/2016] [Accepted: 02/29/2016] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To overcome the challenges of B0 and RF excitation inhomogeneity at ultra-high field MRI, a workflow for volumetric B0 and flip-angle homogenisation was implemented on a human 9.4 T scanner. MATERIALS AND METHODS Imaging was performed with a 9.4 T human MR scanner (Siemens Medical Solutions, Erlangen, Germany) using a 16-channel parallel transmission system. B0- and B1-mapping were done using a dual-echo GRE and transmit phase-encoded DREAM, respectively. B0 shims and a small-tip-angle-approximation kT-points pulse were calculated with an off-line routine and applied to acquire T1- and T 2 (*) -weighted images with MPRAGE and 3D EPI, respectively. RESULTS Over six in vivo acquisitions, the B0-distribution in a region-of-interest defined by a brain mask was reduced down to a full-width-half-maximum of 0.10 ± 0.01 ppm (39 ± 2 Hz). Utilising the kT-points pulses, the normalised RMSE of the excitation was decreased from CP-mode's 30.5 ± 0.9 to 9.2 ± 0.7 % with all B 1 (+) voids eliminated. The SNR inhomogeneities and contrast variations in the T1- and T 2 (*) -weighted volumetric images were greatly reduced which led to successful tissue segmentation of the T1-weighted image. CONCLUSION A 15-minute B0- and flip-angle homogenisation workflow, including the B0- and B1-map acquisitions, was successfully implemented and enabled us to reduce intensity and contrast variations as well as echo-planar image distortions in 9.4 T images.
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Affiliation(s)
- Desmond H Y Tse
- Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
| | | | - Dimo Ivanov
- Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Daniel Brenner
- German Centre for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Jens Hoffmann
- High Field MR Center, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany
| | - Christian Mirkes
- High Field MR Center, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany
- Department for Biomedical Magnetic Resonance, University of Tuebingen, Tuebingen, Germany
| | - Gunamony Shajan
- High Field MR Center, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany
| | - Klaus Scheffler
- High Field MR Center, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany
- Department for Biomedical Magnetic Resonance, University of Tuebingen, Tuebingen, Germany
| | - Kâmil Uludağ
- Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
- Scannexus BV, Maastricht, The Netherlands
| | - Benedikt A Poser
- Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
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Kirilina E, Lutti A, Poser BA, Blankenburg F, Weiskopf N. The quest for the best: The impact of different EPI sequences on the sensitivity of random effect fMRI group analyses. Neuroimage 2015; 126:49-59. [PMID: 26515905 PMCID: PMC4739510 DOI: 10.1016/j.neuroimage.2015.10.071] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 10/05/2015] [Accepted: 10/24/2015] [Indexed: 11/28/2022] Open
Abstract
We compared the sensitivity of standard single-shot 2D echo planar imaging (EPI) to three advanced EPI sequences, i.e., 2D multi-echo EPI, 3D high resolution EPI and 3D dual-echo fast EPI in fixed effect and random effects group level fMRI analyses at 3 T. The study focused on how well the variance reduction in fixed effect analyses achieved by advanced EPI sequences translates into increased sensitivity in the random effects group level analysis. The sensitivity was estimated in a functional MRI experiment of an emotional learning and a reward based learning tasks in a group of 24 volunteers. Each experiment was acquired with the four different sequences. The task-related response amplitude, contrast level and respective t-value were proxies for the functional sensitivity across the brain. All three advanced EPI methods increased the sensitivity in the fixed effects analyses, but standard single-shot 2D EPI provided a comparable performance in random effects group analysis when whole brain coverage and moderate resolution are required. In this experiment inter-subject variability determined the sensitivity of the random effects analysis for most brain regions, making the impact of EPI pulse sequence improvements less relevant or even negligible for random effects analyses. An exception concerns the optimization of EPI reducing susceptibility-related signal loss that translates into an enhanced sensitivity e.g. in the orbitofrontal cortex for multi-echo EPI. Thus, future optimization strategies may best aim at reducing inter-subject variability for higher sensitivity in standard fMRI group studies at moderate spatial resolution. We compared the sensitivity of standard and three advanced EPI sequences in group level fMRI analysis. Advanced EPI methods increased the sensitivity in the fixed effect group analyses. All EPI methods provided similar sensitivity in random effect group analysis. Inter-subject variance determined the sensitivity of the random effect analysis. Future sequence optimization best aim at reducing inter-subject rather then intra-subject variance.
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Affiliation(s)
- Evgeniya Kirilina
- Neurocomputation and Neuroimaging Unit, Department of Psychology and Educational Science, Free University Berlin, Habelschwerdter Allee 45, 14195 Berlin, Germany; Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstrasse 1a, 04103 Leipzig, Germany.
| | - Antoine Lutti
- Laboratoire de Recherche en Neuroimagerie, Département des Neurosciences Cliniques, Centre Hospitalier Universitaire Vaudois, Chemin de Mont Paisible 16, 1011 Lausanne, Switzerland; Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College London, 12 Queen Square, London WC1N 3BG, UK
| | - Benedikt A Poser
- Department of Cognitive Neuroscience, Maastricht Brain Imaging Centre, Faculty of Psychology & Neuroscience, Maastricht University, PO Box 616, 6200MD Maastricht, The Netherlands
| | - Felix Blankenburg
- Neurocomputation and Neuroimaging Unit, Department of Psychology and Educational Science, Free University Berlin, Habelschwerdter Allee 45, 14195 Berlin, Germany
| | - Nikolaus Weiskopf
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstrasse 1a, 04103 Leipzig, Germany; Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College London, 12 Queen Square, London WC1N 3BG, UK
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12
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Narsude M, Gallichan D, van der Zwaag W, Gruetter R, Marques JP. Three-dimensional echo planar imaging with controlled aliasing: A sequence for high temporal resolution functional MRI. Magn Reson Med 2015; 75:2350-61. [PMID: 26173572 DOI: 10.1002/mrm.25835] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 06/16/2015] [Accepted: 06/16/2015] [Indexed: 11/06/2022]
Abstract
PURPOSE In this work, we combine three-dimensional echo planar imaging (3D-EPI) with controlled aliasing to substantially increase temporal resolution in whole-brain functional MRI (fMRI) while minimizing geometry-factor (g-factor) losses. THEORY AND METHODS The study was performed on a 7 Tesla scanner equipped with a 32-channel receive coil. The proposed 3D-EPI-CAIPI sequence was evaluated for: (i) image quality, compared with a conventionally undersampled parallel imaging acquisition; (ii) temporal resolution, the ability to sample and remove physiological signal fluctuations from the fMRI signal of interest and (iii) the ability to distinguish small changes in hemodynamic responses in an event-related fMRI experiment. RESULTS Whole-brain fMRI data with a voxel size of 2 × 2 × 2 mm(3) and temporal resolution of 371 ms could be acquired with acceptable image quality. Ten-fold parallel imaging accelerated 3D-EPI-CAIPI data were shown to lower the maximum g-factor losses up to 62% with respect to a 10-fold accelerated 3D-EPI dataset. FMRI with 400 ms temporal resolution allowed the detection of time-to-peak variations in functional responses due to multisensory facilitation in temporal, occipital and frontal cortices. CONCLUSION 3D-EPI-CAIPI allows increased temporal resolution that enables better characterization of physiological noise, thus improving sensitivity to signal changes of interest. Furthermore, subtle changes in hemodynamic response dynamics can be studied in shorter scan times by avoiding the need for jittering. Magn Reson Med 75:2350-2361, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Mayur Narsude
- Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Department of Radiology, University of Lausanne, Lausanne, Switzerland
| | - Daniel Gallichan
- Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Wietske van der Zwaag
- Centre d'Imagerie BioMédicale, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Rolf Gruetter
- Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Department of Radiology, University of Lausanne, Lausanne, Switzerland.,Centre d'Imagerie BioMédicale, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Department of Radiology, University of Geneva, Geneva, Switzerland
| | - José P Marques
- Centre d'Imagerie BioMédicale, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
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Tijssen RHN, Jenkinson M, Brooks JCW, Jezzard P, Miller KL. Optimizing RetroICor and RetroKCor corrections for multi-shot 3D FMRI acquisitions. Neuroimage 2013; 84:394-405. [PMID: 24018307 DOI: 10.1016/j.neuroimage.2013.08.062] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 08/19/2013] [Accepted: 08/28/2013] [Indexed: 10/26/2022] Open
Abstract
Physiological noise, if unaccounted for, can drastically reduce the statistical significance of detected activation in FMRI. In this paper, we systematically optimize physiological noise regressions for multi-shot 3D FMRI data. First, we investigate whether 3D FMRI data are best corrected in image space (RetroICor) or k-space (RetroKCor), in which each k-space segment can be assigned its unique physiological phase. In addition, the optimal regressor set is determined using the Bayesian Information Criterion (BIC) for a variety of 3D acquisitions corresponding to different image contrasts and k-space readouts. Our simulations and experiments indicate that: (a) k-space corrections are more robust when performed on real/imaginary than magnitude/phase data; (b) k-space corrections do not outperform image-space corrections, despite the ability to synchronize physiological phase to acquisition time more accurately; and (c) the optimal model varied considerably between the various acquisition techniques. These results suggest the use of a tailored set of volume-wide regressors, determined by BIC or other selection criteria, that achieves optimal balance between variance reduction and potential over-fitting.
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Affiliation(s)
- Rob H N Tijssen
- FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK; University Medical Center Utrecht, Utrecht, The Netherlands.
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Barth M, Poser BA. Advances in High-Field BOLD fMRI. Materials (Basel) 2011; 4:1941-55. [PMID: 28824116 DOI: 10.3390/ma4111941] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 10/07/2011] [Accepted: 10/19/2011] [Indexed: 11/17/2022]
Abstract
This review article examines the current state of BOLD fMRI at a high magnetic field strength of 7 Tesla. The following aspects are covered: a short description of the BOLD contrast, spatial and temporal resolution, BOLD sensitivity, localization and spatial specificity, technical challenges as well as an outlook on future developments are given. It is shown that the main technical challenges of performing BOLD fMRI at high magnetic field strengths-namely development of array coils, imaging sequences and parallel imaging reconstruction-have been solved successfully. The combination of these developments has lead to the availability of high-resolution BOLD fMRI protocols that are able to cover the whole brain with a repetition time (TR) shorter than 3 s. The structural information available from these high-resolution fMRI images itself is already very detailed, which helps to co-localize structure and function. Potential future applications include whole-brain connectivity analysis on a laminar resolution and single subject examinations.
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