In this work, we demonstrate the sodium magnetic resonance imaging (MRI) capabilities of a three-dimensional (3D) dual-echo ultrashort echo time (UTE) sequence with a novel rosette petal trajectory (PETALUTE), in comparison to the 3D density-adapted (DA) radial spokes UTE sequence. #mri #ismrm #msk
3D UTE 31P-MRSI with modified rosette k-space (PETALUTE): Comparison with con...Uzay Emir
Phosphorus-31 magnetic resonance spectroscopic imaging (31P-MRSI) provides valuable non-invasive in vivo information on tissue metabolism but is burdened by poor sensitivity and prolonged scan duration. Ultra-short echo time (UTE) acquisitions minimize signal loss when probing signals with relatively short spin-spin relaxation time (T2), while also preventing first-order dephasing. Here, a three-dimensional (3D) UTE sequence with a rosette k-space trajectory is applied to 31P-MRSI at 3T. Conventional chemical shift imaging (CSI) employs highly regular Cartesian k-space sampling, susceptible to substantial artifacts when accelerated via undersampling. In contrast, this novel sequence’s “petal-like” pattern offers incoherent sampling more suitable for compressed sensing (CS). These results showcase the competitive performance of UTE rosette 31P-MRSI against conventional weighted CSI with simulation, phantom, and in vivo leg muscle comparisons.
Modified Rosette PETALUTE for preclinical imagingUzay Emir
We have demonstrated a sequence, PETALUTE, for clinical and preclinical high (3T) and ultra-high fields (>7T) scanners.
The modified Rosette kspace dual-echo Acquisition/ PETALUTE strategy could further enhance integrated and translational research studies to understand human and non-human complex structures and physiologies better.
While Phosphorous (31P) MRS (I) has been promising in experimental and clinical settings since the early 70s, it has been beset by prohibitively lower sensitivity, limited spectral-spatial resolution, and prolonged acquisition. This manuscript and proceedings of the annual scientific meeting of ISMRM in 2022 (REF1) and 2023 (REF2) demonstrate that our novel acquisition strategy, the novel Rosette Trajectory for fast and flexible MR(S)I contrast (Shen et al. 2023 (REF3), later we renamed it as PETALUTE after the translation to the preclinical scanners of 7T and 9.4T), enables operator-independent (1) rapid acquisition (~7 minutes), (2) reconstruction, and (3) processing pipeline, resulting in phosphorous metabolite ratio maps (10 x 10 x 10 mm3) of the whole brain.
In response to the “Repeat it with Me” challenge organized by the Reproducible Research study group of ISMRM, we demonstrated the power of this technique in 5 healthy volunteers at three different institutions with different experimental setups (2nd Place: UTE 31P 3D Rosette MRSI Reproducibility Team, REF4). Since the proposed acquisition/reconstruction/processing pipeline was operator/scanner/coil-independent, the Reproducer sub-teams successfully replicated the findings of the original proceeding in 2022 (REF1). As part of this challenge, we provided some MATLAB scripts and k-space data to reproduce some of the results described in this manuscript. The software and data can be downloaded from https://purr.purdue.edu/projects/ismrm31pmrsi.
These results will likely be of broad interest across clinical settings since the proposed acquisition strategy is not specific to any region, nuclei, or magnetic field and is operator-independent. This study's resolution and signal-to-noise ratios permit the metabolite maps in an experimentally and clinically feasible timeframe at 3 Tesla and 7T.
REF1 Bozymski B, Shen X, Ozen AC, Ibey S, Chiew M, Thomas A, Dydak U, Emir UE. Ultra-Short Echo Time 31P 3D MRSI at 3T with Novel Rosette k-space Trajectory. Proceedings 30th Scientific Meeting, International Society for Magnetic Resonance in Medicine, 2022.
REF2 Farley N, Bozymski B, Dydak U, Emir UE*. Fast 3D 31P MRSI Using Novel Rosette Petal Trajectory at 3T with x4 Accelerated Compressed Sensing. Proceedings 31st Scientific Meeting, International Society for Magnetic Resonance in Medicine, 2023.
REF3 Shen X, Özen AC, Sunjar A, Ilbey S, Sawiak S, Shi R, Chiew M, Emir UE. Ultrashort T2 components imaging of the whole brain using 3D dual-echo UTE MRI with rosette k-space pattern. Magnetic Resonance in Medicine. 2023;89(2):508–521.
REF4 https://challenge.ismrm.org/2023-24-reproducibility-challenge/results-22-23/
Rosette Applications (MRI and MRSI) at UHF human (7T) and animal scanners (9....Uzay Emir
MRI
MRSI
LEAF
PETAL
EGG
ROSETTE
MRI
siemens
bruker
his study aimed to develop a new 3D dual-echo rosette k-space trajectory, specifically for applications of ultra-short echo time (UTE) magnetic resonance imaging (MRI). The direct imaging of the myelin bilayer, which has ultra-short transverse relaxation time (uT2), was acquired to test the performance of the proposed UTE sequence.
Theory and Methods The rosette trajectory was developed based on rotations of a ‘petal-like’ pattern in the kx-ky plane, with oscillated extensions in kz-direction for 3D coverage. Five healthy volunteers were recruited and underwent ten dual-echo rosette UTE scans with varied echo times (TEs). Dual-exponential model fitting was performed to separate uT2 signals, with the output of uT2 fraction, uT2 value and long T2 value.
Results The reconstructed images’ signal contrast between white matter (WM) and grey matter (GM) increased with longer TEs. The WM regions had higher uT2 fraction values than GM (10.9%±1.9% vs. 5.7%±2.4%). The uT2 value was about 0.12 milliseconds in WM.
Conclusion The higher uT2 fraction value in WM compared to GM demonstrated the ability of the proposed sequence to capture rapidly decaying signals.
In this work, we demonstrate the sodium magnetic resonance imaging (MRI) capabilities of a three-dimensional (3D) dual-echo ultrashort echo time (UTE) sequence with a novel rosette petal trajectory (PETALUTE), in comparison to the 3D density-adapted (DA) radial spokes UTE sequence. #mri #ismrm #msk
3D UTE 31P-MRSI with modified rosette k-space (PETALUTE): Comparison with con...Uzay Emir
Phosphorus-31 magnetic resonance spectroscopic imaging (31P-MRSI) provides valuable non-invasive in vivo information on tissue metabolism but is burdened by poor sensitivity and prolonged scan duration. Ultra-short echo time (UTE) acquisitions minimize signal loss when probing signals with relatively short spin-spin relaxation time (T2), while also preventing first-order dephasing. Here, a three-dimensional (3D) UTE sequence with a rosette k-space trajectory is applied to 31P-MRSI at 3T. Conventional chemical shift imaging (CSI) employs highly regular Cartesian k-space sampling, susceptible to substantial artifacts when accelerated via undersampling. In contrast, this novel sequence’s “petal-like” pattern offers incoherent sampling more suitable for compressed sensing (CS). These results showcase the competitive performance of UTE rosette 31P-MRSI against conventional weighted CSI with simulation, phantom, and in vivo leg muscle comparisons.
Modified Rosette PETALUTE for preclinical imagingUzay Emir
We have demonstrated a sequence, PETALUTE, for clinical and preclinical high (3T) and ultra-high fields (>7T) scanners.
The modified Rosette kspace dual-echo Acquisition/ PETALUTE strategy could further enhance integrated and translational research studies to understand human and non-human complex structures and physiologies better.
While Phosphorous (31P) MRS (I) has been promising in experimental and clinical settings since the early 70s, it has been beset by prohibitively lower sensitivity, limited spectral-spatial resolution, and prolonged acquisition. This manuscript and proceedings of the annual scientific meeting of ISMRM in 2022 (REF1) and 2023 (REF2) demonstrate that our novel acquisition strategy, the novel Rosette Trajectory for fast and flexible MR(S)I contrast (Shen et al. 2023 (REF3), later we renamed it as PETALUTE after the translation to the preclinical scanners of 7T and 9.4T), enables operator-independent (1) rapid acquisition (~7 minutes), (2) reconstruction, and (3) processing pipeline, resulting in phosphorous metabolite ratio maps (10 x 10 x 10 mm3) of the whole brain.
In response to the “Repeat it with Me” challenge organized by the Reproducible Research study group of ISMRM, we demonstrated the power of this technique in 5 healthy volunteers at three different institutions with different experimental setups (2nd Place: UTE 31P 3D Rosette MRSI Reproducibility Team, REF4). Since the proposed acquisition/reconstruction/processing pipeline was operator/scanner/coil-independent, the Reproducer sub-teams successfully replicated the findings of the original proceeding in 2022 (REF1). As part of this challenge, we provided some MATLAB scripts and k-space data to reproduce some of the results described in this manuscript. The software and data can be downloaded from https://purr.purdue.edu/projects/ismrm31pmrsi.
These results will likely be of broad interest across clinical settings since the proposed acquisition strategy is not specific to any region, nuclei, or magnetic field and is operator-independent. This study's resolution and signal-to-noise ratios permit the metabolite maps in an experimentally and clinically feasible timeframe at 3 Tesla and 7T.
REF1 Bozymski B, Shen X, Ozen AC, Ibey S, Chiew M, Thomas A, Dydak U, Emir UE. Ultra-Short Echo Time 31P 3D MRSI at 3T with Novel Rosette k-space Trajectory. Proceedings 30th Scientific Meeting, International Society for Magnetic Resonance in Medicine, 2022.
REF2 Farley N, Bozymski B, Dydak U, Emir UE*. Fast 3D 31P MRSI Using Novel Rosette Petal Trajectory at 3T with x4 Accelerated Compressed Sensing. Proceedings 31st Scientific Meeting, International Society for Magnetic Resonance in Medicine, 2023.
REF3 Shen X, Özen AC, Sunjar A, Ilbey S, Sawiak S, Shi R, Chiew M, Emir UE. Ultrashort T2 components imaging of the whole brain using 3D dual-echo UTE MRI with rosette k-space pattern. Magnetic Resonance in Medicine. 2023;89(2):508–521.
REF4 https://challenge.ismrm.org/2023-24-reproducibility-challenge/results-22-23/
Rosette Applications (MRI and MRSI) at UHF human (7T) and animal scanners (9....Uzay Emir
MRI
MRSI
LEAF
PETAL
EGG
ROSETTE
MRI
siemens
bruker
his study aimed to develop a new 3D dual-echo rosette k-space trajectory, specifically for applications of ultra-short echo time (UTE) magnetic resonance imaging (MRI). The direct imaging of the myelin bilayer, which has ultra-short transverse relaxation time (uT2), was acquired to test the performance of the proposed UTE sequence.
Theory and Methods The rosette trajectory was developed based on rotations of a ‘petal-like’ pattern in the kx-ky plane, with oscillated extensions in kz-direction for 3D coverage. Five healthy volunteers were recruited and underwent ten dual-echo rosette UTE scans with varied echo times (TEs). Dual-exponential model fitting was performed to separate uT2 signals, with the output of uT2 fraction, uT2 value and long T2 value.
Results The reconstructed images’ signal contrast between white matter (WM) and grey matter (GM) increased with longer TEs. The WM regions had higher uT2 fraction values than GM (10.9%±1.9% vs. 5.7%±2.4%). The uT2 value was about 0.12 milliseconds in WM.
Conclusion The higher uT2 fraction value in WM compared to GM demonstrated the ability of the proposed sequence to capture rapidly decaying signals.
UTE 31P 3D Rosette MRSI reproducibility Team has demonstrated the Reproducibility of the method. The method has been challenged on #siemenshealthineers PET-MRI (mMR) and Prisma 3T scanners.ISMRM #spectroscopy ISMRM ChallengeISMRM RAPID Biomedical
https://lnkd.in/gnjCHtu2
Submillimeter fMRI Acquisition using a dual-echo Rosette kspace trajectory at 3TUzay Emir
n this study, we overcome the technological barrier against acquiring submillimeter resolution (~ 0.5 mm) fMRI data at 3T via a novel dual-echo Rosette k-space design. This design results in the fine representation of activation maps in two different functional tasks and might be a springboard in neuroimaging by providing very high-resolution spatiotemporal dynamics of neural networks. The method will be further evolved with the feedback from the MRI community via the GitHub platform as such for further acceleration, inflow saturation, and 3D coverage via 3D sampling and/or multiband approaches.
3D-UTE Rosette MRI and MRSI at UHF human (7T) and animal scanners (9.4T) usin...Uzay Emir
#ismrm #ISMRM2022 #ISMRM22
3D-UTE Rosette Applications (MRI and MRSI) at UHF human (7T) and animal scanners (9.4T) using The Berkeley Advanced Reconstruction Toolbox (BART) toolbox
Uzay Emir
Afternoon Tea with BART
Time: 15:45-16:45
Simultaneous Measurement of functional MRI and MRS by Fast Non-water Suppress...Uzay Emir
The non-water suppressed magnetic resonance spectroscopic imaging (MRSI) sequence with concentric k-space trajectory was proposed to measure functional MRI and MRSI signals simultaneously. A right-hand finger-tapping task was performed at 3T MRI scanner to test the simultaneous hemodynamic and neurochemical measurements in the human primary motor cortex. The results showed a significant overlap betweenT2* and metabolite (glutamate) changes.
Quantitative Susceptibility Mapping (QSM) Using High-resolution Ultra-Short E...Uzay Emir
Karnik A, Shen X, Monsivais H, Sunjar A, Özen A, Ilbey S, Chiew M, Cakmak M, Rispoli J, Emir UE., Quantitative Susceptibility Mapping (QSM) Using High-resolution Ultra-Short Echo Time (UTE) MRI with Rosette k-space Pattern International Society for Magnetic Resonance in Medicine Annual Meeting 2022
High Resolution 3D Ultra-Short Echo Time MRI with Rosette k-Space Pattern for...Uzay Emir
High Resolution 3D Ultra-Short Echo Time MRI with Rosette k-Space Pattern for Brain Iron Content Mapping
Shen X, Özen A, Monsivais H, Ilbey S, Susnjar A, Karnik A, Chiew M, Emir UE. High Resolution 3D Ultra-Short Echo Time MRI with Rosette k-Space Pattern for Brain Iron Content Mapping, International Society for Magnetic Resonance in Medicine Annual Meeting 2022
1H/31P 3D MRSI at 3T with Novel Rosette k-space Trajectory with compressed se...Uzay Emir
1H/31P 3D MRSI at 3T with Novel Rosette k-space Trajectory with compressed sensing reconstruction
Bozymski B, Shen X, Özen A, Ilbey S, Thomas MA, Chiew M, Dydak U, Emir UE. Ultra-Short Echo Time 31P 3D MRSI at 3T with Novel Rosette k-space Trajectory, International Society for Magnetic Resonance in Medicine Annual Meeting 2022
CMRR workshop in vivo GABA Glutamate and fMRI BOLD imaging Event-Related fMRSUzay Emir
CMRR workshop
Time-Resolved fMRI-fMRS measures simultaneous Neurotransmitters and BOLD-fMRI signals in the human brain at 7T
GABA Glutamate UHF Semi-laser
Advanced Magnetic Resonance Spectroscopy Protocol at 7T
7T hardware (Siemens Scanner and Nova Medical head coil), BaTiO3 dielectric padding
Ip et al., 2017 NeuroImage
Event-Related fMRS A transient break in excitatory-inhibitory balance
Time-Resolved fMRI-fMRS measures simultaneous Neurotransmitters and BOLD-fMRI...Uzay Emir
Time-Resolved fMRI-fMRS measures simultaneous Neurotransmitters and BOLD-fMRI signals in the human brain at 7T
2021 Minnesota Workshop on High and Ultra-high Field Imaging
https://bit.ly/3kE66qk
Proposing an Accelerated Magnetic Resonance Spectroscopic Imaging Acquisition...Uzay Emir
Proposing an Accelerated Magnetic Resonance Spectroscopic Imaging Acquisition as a Promising Tool to Investigate Heterogeneous Renal Cell Carcinoma: Feasibility and Reliability Study at 3 T
Comparison Between 2-Hydroxyglutarate Detection Methods at 3T
False-Positive Measurement at 2-Hydroxyglutarate MR Spectroscopy in Isocitrate Dehydrogenase Wild-Type
Non-invasive detection of 2-hydroxyglutarate in IDH-mutated gliomas using
Advances and Challenges in Assessing 2-Hydroxyglutarate in Gliomas by Magnetic Resonance Spectroscopy
Detection of oncogenic IDH1 mutations using magnetic resonance spectroscopy of 2-hydroxyglutarate
standardization
Across-vendor
semi-LASER
single-voxel
MRS
3T
GABA spectroscopy
edited GABA 1H MEGA-PRESS spectra
GABA-edited
Magnetic Resonance Spectroscopy, MRI, Human Connectome, 2-HG, 2-hydroxyglutarate, zoom, zoom MRSI, reduced field of View, rFOV, Cerebellum, High-resolution, IDH, Isocitrate, IDH1, IDH2, Cancer, Glioma, Parcellation, Macro Anatomical
Functional
Myeloarchitectonic
functional MRS
MR Spectroscopy Study Group
fMRI - fMRSI
glutamate
gaba
fMRS
ISMRM
standardization
Across-vendor
semi-LASER
single-voxel
MRS
3T
human brain mapping
GABAergic inhibition in the human visual cortex relates to eye dominanceUzay Emir
Binocular vision is created by fusing the separate inputs arriving from left and right eye. Even in the healthy visual system there is often a small imbalance in the strength of these connections projecting to the brain. ‘Eye dominance’ provides a measure of the perceptual dominance of one eye over the other. Theoretical models suggest that eye dominance is related to reciprocal inhibition between monocular units in the primary visual cortex, the first location where the binocular input is combined. As the specific inhibitory interactions in the binocular visual system critically depend on the presence of visual input, we sought to test the role of inhibition by measuring the inhibitory (GABA) neurotransmitters during monocular visual stimulation of the dominant and the non-dominant eye. GABA levels were acquired in a single volume of interest in the early visual cortex, including V1 from both hemispheres, using a combined functional magnetic resonance imaging and magnetic resonance spectroscopy (combined fMRI-MRS) sequence on a 7-Tesla MRI scanner. Individuals with stronger eye dominance had a greater difference in GABAergic inhibition between the eyes. This relationship was present only when the visual system was actively processing sensory input and was not present at rest. We provide the first evidence that imbalances in GABA levels during ongoing sensory processing are related to eye dominance in the human visual cortex. Our finding supports the view that intracortical inhibition underlies normal eye dominance.
GABA spectroscopy
edited GABA 1H MEGA-PRESS spectra
GABA-edited
Magnetic Resonance Spectroscopy, MRI, Human Connectome, 2-HG, 2-hydroxyglutarate, zoom, zoom MRSI, reduced field of View, rFOV, Cerebellum, High-resolution, IDH, Isocitrate, IDH1, IDH2, Cancer, Glioma, Parcellation, Macro Anatomical
Functional
Myeloarchitectonic
functional MRS
MR Spectroscopy Study Group
fMRI - fMRSI
glutamate
gaba
fMRS
ISMRM
standardization
Across-vendor
semi-LASER
single-voxel
MRS
3T
human brain mapping
UTE 31P 3D Rosette MRSI reproducibility Team has demonstrated the Reproducibility of the method. The method has been challenged on #siemenshealthineers PET-MRI (mMR) and Prisma 3T scanners.ISMRM #spectroscopy ISMRM ChallengeISMRM RAPID Biomedical
https://lnkd.in/gnjCHtu2
Submillimeter fMRI Acquisition using a dual-echo Rosette kspace trajectory at 3TUzay Emir
n this study, we overcome the technological barrier against acquiring submillimeter resolution (~ 0.5 mm) fMRI data at 3T via a novel dual-echo Rosette k-space design. This design results in the fine representation of activation maps in two different functional tasks and might be a springboard in neuroimaging by providing very high-resolution spatiotemporal dynamics of neural networks. The method will be further evolved with the feedback from the MRI community via the GitHub platform as such for further acceleration, inflow saturation, and 3D coverage via 3D sampling and/or multiband approaches.
3D-UTE Rosette MRI and MRSI at UHF human (7T) and animal scanners (9.4T) usin...Uzay Emir
#ismrm #ISMRM2022 #ISMRM22
3D-UTE Rosette Applications (MRI and MRSI) at UHF human (7T) and animal scanners (9.4T) using The Berkeley Advanced Reconstruction Toolbox (BART) toolbox
Uzay Emir
Afternoon Tea with BART
Time: 15:45-16:45
Simultaneous Measurement of functional MRI and MRS by Fast Non-water Suppress...Uzay Emir
The non-water suppressed magnetic resonance spectroscopic imaging (MRSI) sequence with concentric k-space trajectory was proposed to measure functional MRI and MRSI signals simultaneously. A right-hand finger-tapping task was performed at 3T MRI scanner to test the simultaneous hemodynamic and neurochemical measurements in the human primary motor cortex. The results showed a significant overlap betweenT2* and metabolite (glutamate) changes.
Quantitative Susceptibility Mapping (QSM) Using High-resolution Ultra-Short E...Uzay Emir
Karnik A, Shen X, Monsivais H, Sunjar A, Özen A, Ilbey S, Chiew M, Cakmak M, Rispoli J, Emir UE., Quantitative Susceptibility Mapping (QSM) Using High-resolution Ultra-Short Echo Time (UTE) MRI with Rosette k-space Pattern International Society for Magnetic Resonance in Medicine Annual Meeting 2022
High Resolution 3D Ultra-Short Echo Time MRI with Rosette k-Space Pattern for...Uzay Emir
High Resolution 3D Ultra-Short Echo Time MRI with Rosette k-Space Pattern for Brain Iron Content Mapping
Shen X, Özen A, Monsivais H, Ilbey S, Susnjar A, Karnik A, Chiew M, Emir UE. High Resolution 3D Ultra-Short Echo Time MRI with Rosette k-Space Pattern for Brain Iron Content Mapping, International Society for Magnetic Resonance in Medicine Annual Meeting 2022
1H/31P 3D MRSI at 3T with Novel Rosette k-space Trajectory with compressed se...Uzay Emir
1H/31P 3D MRSI at 3T with Novel Rosette k-space Trajectory with compressed sensing reconstruction
Bozymski B, Shen X, Özen A, Ilbey S, Thomas MA, Chiew M, Dydak U, Emir UE. Ultra-Short Echo Time 31P 3D MRSI at 3T with Novel Rosette k-space Trajectory, International Society for Magnetic Resonance in Medicine Annual Meeting 2022
CMRR workshop in vivo GABA Glutamate and fMRI BOLD imaging Event-Related fMRSUzay Emir
CMRR workshop
Time-Resolved fMRI-fMRS measures simultaneous Neurotransmitters and BOLD-fMRI signals in the human brain at 7T
GABA Glutamate UHF Semi-laser
Advanced Magnetic Resonance Spectroscopy Protocol at 7T
7T hardware (Siemens Scanner and Nova Medical head coil), BaTiO3 dielectric padding
Ip et al., 2017 NeuroImage
Event-Related fMRS A transient break in excitatory-inhibitory balance
Time-Resolved fMRI-fMRS measures simultaneous Neurotransmitters and BOLD-fMRI...Uzay Emir
Time-Resolved fMRI-fMRS measures simultaneous Neurotransmitters and BOLD-fMRI signals in the human brain at 7T
2021 Minnesota Workshop on High and Ultra-high Field Imaging
https://bit.ly/3kE66qk
Proposing an Accelerated Magnetic Resonance Spectroscopic Imaging Acquisition...Uzay Emir
Proposing an Accelerated Magnetic Resonance Spectroscopic Imaging Acquisition as a Promising Tool to Investigate Heterogeneous Renal Cell Carcinoma: Feasibility and Reliability Study at 3 T
Comparison Between 2-Hydroxyglutarate Detection Methods at 3T
False-Positive Measurement at 2-Hydroxyglutarate MR Spectroscopy in Isocitrate Dehydrogenase Wild-Type
Non-invasive detection of 2-hydroxyglutarate in IDH-mutated gliomas using
Advances and Challenges in Assessing 2-Hydroxyglutarate in Gliomas by Magnetic Resonance Spectroscopy
Detection of oncogenic IDH1 mutations using magnetic resonance spectroscopy of 2-hydroxyglutarate
standardization
Across-vendor
semi-LASER
single-voxel
MRS
3T
GABA spectroscopy
edited GABA 1H MEGA-PRESS spectra
GABA-edited
Magnetic Resonance Spectroscopy, MRI, Human Connectome, 2-HG, 2-hydroxyglutarate, zoom, zoom MRSI, reduced field of View, rFOV, Cerebellum, High-resolution, IDH, Isocitrate, IDH1, IDH2, Cancer, Glioma, Parcellation, Macro Anatomical
Functional
Myeloarchitectonic
functional MRS
MR Spectroscopy Study Group
fMRI - fMRSI
glutamate
gaba
fMRS
ISMRM
standardization
Across-vendor
semi-LASER
single-voxel
MRS
3T
human brain mapping
GABAergic inhibition in the human visual cortex relates to eye dominanceUzay Emir
Binocular vision is created by fusing the separate inputs arriving from left and right eye. Even in the healthy visual system there is often a small imbalance in the strength of these connections projecting to the brain. ‘Eye dominance’ provides a measure of the perceptual dominance of one eye over the other. Theoretical models suggest that eye dominance is related to reciprocal inhibition between monocular units in the primary visual cortex, the first location where the binocular input is combined. As the specific inhibitory interactions in the binocular visual system critically depend on the presence of visual input, we sought to test the role of inhibition by measuring the inhibitory (GABA) neurotransmitters during monocular visual stimulation of the dominant and the non-dominant eye. GABA levels were acquired in a single volume of interest in the early visual cortex, including V1 from both hemispheres, using a combined functional magnetic resonance imaging and magnetic resonance spectroscopy (combined fMRI-MRS) sequence on a 7-Tesla MRI scanner. Individuals with stronger eye dominance had a greater difference in GABAergic inhibition between the eyes. This relationship was present only when the visual system was actively processing sensory input and was not present at rest. We provide the first evidence that imbalances in GABA levels during ongoing sensory processing are related to eye dominance in the human visual cortex. Our finding supports the view that intracortical inhibition underlies normal eye dominance.
GABA spectroscopy
edited GABA 1H MEGA-PRESS spectra
GABA-edited
Magnetic Resonance Spectroscopy, MRI, Human Connectome, 2-HG, 2-hydroxyglutarate, zoom, zoom MRSI, reduced field of View, rFOV, Cerebellum, High-resolution, IDH, Isocitrate, IDH1, IDH2, Cancer, Glioma, Parcellation, Macro Anatomical
Functional
Myeloarchitectonic
functional MRS
MR Spectroscopy Study Group
fMRI - fMRSI
glutamate
gaba
fMRS
ISMRM
standardization
Across-vendor
semi-LASER
single-voxel
MRS
3T
human brain mapping