scholarly journals High resolution atlas of the venous brain vasculature from 7 T quantitative susceptibility maps

2018 ◽  
Author(s):  
Julia Huck ◽  
Yvonne Wanner ◽  
Audrey P. Fan ◽  
Anna-Thekla Jäger ◽  
Sophia Grahl ◽  
...  
Keyword(s):  
Human Brain ◽  
Blood Oxygen Level Dependent ◽  
7 Tesla ◽  
Cerebral Vein ◽  
Registration Method ◽  
Isotropic Resolution ◽  
Common Location ◽  
Susceptibility Maps ◽  
Venous Vasculature

AbstractThe vascular organization of the human brain can determine neurological and neurophysiological functions, yet thus far it has not been comprehensively mapped. Aging and diseases such as dementia are known to be associated with changes to the vasculature and normative data could help detect these vascular changes in neuroimaging studies. Furthermore, given the well-known impact of venous vessels on the blood oxygen level dependent (BOLD) signal, information about the common location of veins could help detect biases in existing datasets. In this work, a quantitative atlas of the venous vasculature using quantitative susceptibility maps (QSM) acquired with a 0.6 mm isotropic resolution is presented. The Venous Neuroanatomy (VENAT) atlas was created from 5 repeated 7 Tesla MRI measurements in young and healthy volunteers (n = 20, 10 females, mean age = 25.1 ± 2.5 years) using a two-step registration method on 3D segmentations of the venous vasculature. This cerebral vein atlas includes the average vessel location, diameter (mean: 0.84 ± 0.33 mm) and curvature (0.11 ± 0.05 mm−1) from all participants and provides an in vivo measure of the angio-architectonic organization of the human brain and its variability. This atlas can be used as a basis to understand changes in the vasculature during aging and neurodegeneration, as well as vascular and physiological effects in neuroimaging.

scholarly journals 7 Tesla MRI of the ex vivo human brain at 100 micron resolution

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Brian L. Edlow ◽  
Azma Mareyam ◽  
Andreas Horn ◽  
Jonathan R. Polimeni ◽  
Thomas Witzel ◽  
...  
Keyword(s):  
Human Brain ◽  
Ex Vivo ◽  
Three Dimensional ◽  
Academic Community ◽  
7 Tesla ◽  
Brain Anatomy ◽  
Isotropic Resolution ◽  
Scan Time ◽  
Brain Specimen ◽  
7 Tesla Mri

Abstract We present an ultra-high resolution MRI dataset of an ex vivo human brain specimen. The brain specimen was donated by a 58-year-old woman who had no history of neurological disease and died of non-neurological causes. After fixation in 10% formalin, the specimen was imaged on a 7 Tesla MRI scanner at 100 µm isotropic resolution using a custom-built 31-channel receive array coil. Single-echo multi-flip Fast Low-Angle SHot (FLASH) data were acquired over 100 hours of scan time (25 hours per flip angle), allowing derivation of synthesized FLASH volumes. This dataset provides an unprecedented view of the three-dimensional neuroanatomy of the human brain. To optimize the utility of this resource, we warped the dataset into standard stereotactic space. We now distribute the dataset in both native space and stereotactic space to the academic community via multiple platforms. We envision that this dataset will have a broad range of investigational, educational, and clinical applications that will advance understanding of human brain anatomy in health and disease.

scholarly journals Imaging of the pial arterial vasculature of the human brain in vivo using high-resolution 7T time-of-flight angiography

2021 ◽  
Author(s):  
Saskia Bollmann ◽  
Hendrik Mattern ◽  
Michaël Bernier ◽  
Simon R Robinson ◽  
Daniel Park ◽  
...  
Keyword(s):  
Blood Flow ◽  
High Resolution ◽  
Human Brain ◽  
Blood Supply ◽  
Time Of Flight ◽  
Image Resolution ◽  
Pial Arteries ◽  
Isotropic Resolution ◽  
Tof Mra

The pial arterial vasculature of the human brain is the only blood supply to the neocortex, but quantitative data on the morphology and topology of these mesoscopic vessels (diameter 50-300 μm) remains scarce. Because it is commonly assumed that blood flow velocities in these vessels are prohibitively slow, non-invasive time-of-flight MRI angiography (TOF-MRA)-which is well-suited to high 3D imaging resolutions-has not been applied to imaging the pial arteries. Here, we provide a theoretical framework that outlines how TOF-MRA can visualize small pial arteries in vivo, by employing extremely small voxels at the size of individual vessels. We then provide evidence for this theory by imaging the pial arteries at 140-μm isotropic resolution using a 7T MRI scanner and prospective motion correction, and show that pial arteries one voxel-width in diameter can be detected. We conclude that imaging pial arteries is not limited by slow blood flow, but instead by achievable image resolution. This study represents the first targeted, comprehensive account of imaging pial arteries in vivo in the human brain. This ultra-high-resolution angiography will enable the characterization of pial vascular anatomy across the brain to investigate patterns of blood supply and relationships between vascular and functional architecture.

scholarly journals Mapping the human subcortical auditory system using histology, post mortem MRI and in vivo MRI at 7T

2019 ◽  
Author(s):  
Kevin Richard Sitek ◽  
Omer Faruk Gulban ◽  
Evan Calabrese ◽  
G. Allan Johnson ◽  
Agustin Lage-Castellanos ◽  
...  
Keyword(s):  
Auditory System ◽  
Structural Connectivity ◽  
Three Dimensional ◽  
Auditory Pathway ◽  
7 Tesla ◽  
Post Mortem ◽  
Subcortical Structures ◽  
Isotropic Resolution ◽  
Histological Data

AbstractStudying the human subcortical auditory system non-invasively is challenging due to its small, densely packed structures deep within the brain. Additionally, the elaborate three-dimensional (3-D) structure of the system can be difficult to understand based on currently available 2-D schematics and animal models. We addressed these issues using a combination of histological data, post mortem magnetic resonance imaging (MRI), and in vivo MRI at 7 Tesla. We created anatomical atlases based on state-of-the-art human histology (BigBrain) and post mortem MRI (50 μm). We measured functional MRI (fMRI) responses to natural sounds and demonstrate that the functional localization of subcortical structures is reliable within individual participants who were scanned in two different experiments. Further, a group functional atlas derived from the functional data locates these structures with a median distance below 2mm. Using diffusion MRI tractography, we revealed structural connectivity maps of the human subcortical auditory pathway both in vivo (1050 μm isotropic resolution) and post mortem (200 μm isotropic resolution). This work captures current MRI capabilities for investigating the human subcortical auditory system, describes challenges that remain, and contributes novel, openly available data, atlases, and tools for researching the human auditory system.

scholarly journals In vivo 3D Reconstruction of the Human Pallidothalamic and Nigrothalamic Pathways With Super-Resolution 7T MR Track Density Imaging and Fiber Tractography

2021 ◽  
Vol 15 ◽  
Author(s):  
Dae-Hyuk Kwon ◽  
Sun Ha Paek ◽  
Young-Bo Kim ◽  
Haigun Lee ◽  
Zang-Hee Cho
Keyword(s):  
Basal Ganglia ◽  
3D Reconstruction ◽  
Human Brain ◽  
Super Resolution ◽  
Track Density ◽  
7 Tesla ◽  
Fiber Tractography ◽  
Resolution Limit ◽  
Magnetic Resonance Imaging Mri

The output network of the basal ganglia plays an important role in motor, associative, and limbic processing and is generally characterized by the pallidothalamic and nigrothalamic pathways. However, these connections in the human brain remain difficult to elucidate because of the resolution limit of current neuroimaging techniques. The present study aimed to investigate the mesoscopic nature of these connections between the thalamus, substantia nigra pars reticulata, and globus pallidus internal segment using 7 Tesla (7T) magnetic resonance imaging (MRI). In this study, track-density imaging (TDI) of the whole human brain was employed to overcome the limitations of observing the pallidothalamic and nigrothalamic tracts. Owing to the super-resolution of the TD images, the substructures of the SN, as well as the associated tracts, were identified. This study demonstrates that 7T MRI and MR tractography can be used to visualize anatomical details, as well as 3D reconstruction, of the output projections of the basal ganglia.

scholarly journals 7 Tesla MRI of the ex vivo human brain at 100 micron resolution

2019 ◽  
Author(s):  
Brian L. Edlow ◽  
Azma Mareyam ◽  
Andreas Horn ◽  
Jonathan R. Polimeni ◽  
Thomas Witzel ◽  
...  
Keyword(s):  
Human Brain ◽  
Ex Vivo ◽  
Three Dimensional ◽  
Academic Community ◽  
7 Tesla ◽  
Brain Anatomy ◽  
Isotropic Resolution ◽  
Scan Time ◽  
Brain Specimen ◽  
7 Tesla Mri

AbstractWe present an ultra-high resolution MRI dataset of an ex vivo human brain specimen. The brain specimen was donated by a 58-year-old woman who had no history of neurological disease and died of non-neurological causes. After fixation in 10% formalin, the specimen was imaged on a 7 Tesla MRI scanner at 100 μm isotropic resolution using a custom-built 31-channel receive array coil. Single-echo multi-flip Fast Low-Angle SHot (FLASH) data were acquired over 100 hours of scan time (25 hours per flip angle), allowing derivation of a T1 parameter map and synthesized FLASH volumes. This dataset provides an unprecedented view of the three-dimensional neuroanatomy of the human brain. To optimize the utility of this resource, we warped the dataset into standard stereotactic space. We now distribute the dataset in both native space and stereotactic space to the academic community via multiple platforms. We envision that this dataset will have a broad range of investigational, educational, and clinical applications that will advance understanding of human brain anatomy in health and disease.

scholarly journals A Nested Eight-Channel Transmit Array With Open-Face Concept for Human Brain Imaging at 7 Tesla

2021 ◽  
Vol 9 ◽  
Author(s):  
Sydney N. Williams ◽  
Sarah Allwood-Spiers ◽  
Paul McElhinney ◽  
Gavin Paterson ◽  
Jürgen Herrler ◽  
...  
Keyword(s):  
Human Brain ◽  
High Performance ◽  
Patient Monitoring ◽  
Single Channel ◽  
7 Tesla ◽  
Parallel Transmit ◽  
The Individual ◽  
Open Face ◽  
Head Coil

Purpose: Parallel transmit technology for MRI at 7 tesla will significantly benefit from high performance transmit arrays that offer high transmit efficiency and low mutual coupling between the individual array elements. A novel dual-mode transmit array with nested array elements has been developed to support imaging the human brain in both the single-channel (sTx) and parallel-transmit (pTx) excitation modes of a 7 tesla MRI scanner. In this work, the design, implementation, validation, specific absorption rate (SAR) management, and performance of the head coil is presented.Methods: The transmit array consisted of a nested arrangement to improve decoupling between the second-neighboring elements. Two large cut-outs were introduced in the RF shield for an open-face design to reduce claustrophobia and to allow patient monitoring. A hardware interface allows the coil to be used in both the sTx and pTx modes. SAR monitoring is done with virtual observation points (VOP) derived from human body models. The transmit efficiency and coverage is compared with the commercial single-channel and parallel-transmit head coils.Results: Decoupling inductors between the second-neighboring coil elements reduced the coupling to less than −20 dB. Local SAR estimates from the electromagnetic (EM) simulations were always less than the EM-based VOPs, which in turn were always less than scanner predictions and measurements for static and dynamic pTx waveforms. In sTx mode, we demonstrate improved coverage of the brain compared to the commercial sTx coil. The transmit efficiency is within 10% of the commercial pTx coil despite the two large cut-outs in the RF shield. In pTx mode, improved signal homogeneity was shown when the Universal Pulse was used for acquisition in vivo.Conclusion: A novel head coil which includes a nested eight-channel transmit array has been presented. The large cut-outs improve patient monitoring and reduce claustrophobia. For pTx mode, the EM simulation and VOP-based SAR management provided greater flexibility to apply pTx methods without the limitations of SAR constraints. For scanning in vivo, the coil was shown to provide an improved coverage in sTx mode compared to a standard commercial head coil.

scholarly journals T1-weighted in vivo human whole brain MRI dataset with an ultrahigh isotropic resolution of 250 μm

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Falk Lüsebrink ◽  
Alessandro Sciarra ◽  
Hendrik Mattern ◽  
Renat Yakupov ◽  
Oliver Speck
Keyword(s):  
Brain Mri ◽  
Brain Magnetic Resonance Imaging ◽  
Brain Atlas ◽  
7 Tesla ◽  
Ultrahigh Resolution ◽  
Raw Data ◽  
Whole Brain ◽  
Isotropic Resolution ◽  
High Magnetic Field Strength

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.

In vivo imaging of the human brain at 1.5 T with 0.6-mm isotropic resolution

2010 ◽  
Vol 28 (3) ◽  
pp. 329-340 ◽  
Author(s):  
Ana-Maria Oros-Peusquens ◽  
Tony Stoecker ◽  
Katrin Amunts ◽  
Karl Zilles ◽  
Nadim Jon Shah
Keyword(s):  
Human Brain ◽  
In Vivo Imaging ◽  
Isotropic Resolution

scholarly journals Mapping Human Somatosensory Cortex in Individual Subjects With 7T Functional MRI

2010 ◽  
Vol 103 (5) ◽  
pp. 2544-2556 ◽  
Author(s):  
R. M. Sanchez-Panchuelo ◽  
S. Francis ◽  
R. Bowtell ◽  
D. Schluppeck
Keyword(s):  
Somatosensory Cortex ◽  
High Field ◽  
Tactile Stimulation ◽  
Normal Subjects ◽  
Blood Oxygen Level Dependent ◽  
7 Tesla ◽  
Topographic Mapping ◽  
Ultra High Field ◽  
Individual Subject ◽  
Isotropic Resolution

Functional magnetic resonance imaging (fMRI) is now routinely used to map the topographic organization of human visual cortex. Mapping the detailed topography of somatosensory cortex, however, has proven to be more difficult. Here we used the increased blood-oxygen-level-dependent contrast-to-noise ratio at ultra-high field (7 Tesla) to measure the topographic representation of the digits in human somatosensory cortex at 1 mm isotropic resolution in individual subjects. A “traveling wave” paradigm was used to locate regions of cortex responding to periodic tactile stimulation of each distal phalangeal digit. Tactile stimulation was applied sequentially to each digit of the left hand from thumb to little finger (and in the reverse order). In all subjects, we found an orderly map of the digits on the posterior bank of the central sulcus (postcentral gyrus). Additionally, we measured event-related responses to brief stimuli for comparison with the topographic mapping data and related the fMRI responses to anatomical images obtained with an inversion-recovery sequence. Our results have important implications for the study of human somatosensory cortex and underscore the practical utility of ultra-high field functional imaging with 1 mm isotropic resolution for neuroscience experiments. First, topographic mapping of somatosensory cortex can be achieved in 20 min, allowing time for further experiments in the same session. Second, the maps are of sufficiently high resolution to resolve the representations of all five digits and third, the measurements are robust and can be made in an individual subject. These combined advantages will allow somatotopic fMRI to be used to measure the representation of digits in patients undergoing rehabilitation or plastic changes after peripheral nerve damage as well as tracking changes in normal subjects undergoing perceptual learning.

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