scholarly journals Fusion of quantitative susceptibility maps and T1-weighted images improve brain tissue contrast in primates

2021 ◽  
Author(s):  
Rakshit Dadarwal ◽  
Michael Ortiz-Rios ◽  
Susann Boretius
Keyword(s):  
White Matter ◽  
Brain Tissue ◽  
Brain Structures ◽  
Macaque Monkey ◽  
List Type ◽  
Subcortical Structures ◽  
Tissue Segmentation ◽  
Tissue Contrast ◽  
T1 Contrast ◽  
The Brain

AbstractRecent progress in quantitative susceptibility mapping (QSM) has enabled the accurate delineation of submillimeter scale subcortical brain structures in humans. QSM reflects the magnetic susceptibility arising from the spatial distribution of iron, myelin, and calcium in the brain. The simultaneous visualization of cortical, subcortical, and white matter structure remains, however, challenging, utilizing QSM data solely. Here we present TQ-SILiCON, a fusion method that enhances the contrast of cortical and subcortical structures and provides an excellent white matter delineation by combining QSM and conventional T1-weighted (T1w) images. In this study, we first established QSM in the macaque monkey to map iron-rich subcortical structures. Implementing the same QSM acquisition and analyses methods allowed a similar accurate delineation of subcortical structures in humans. Moreover, applying automatic brain tissue segmentation to TQ-SILiCON images of the macaque improved the classification of the brain tissue types as compared to the single T1 contrast. Furthermore, we validate our dual-contrast fusion approach in humans and similarly demonstrate improvements in automated segmentation of cortical and subcortical structures. We believe the proposed contrast will facilitate translational studies in non-human primates to investigate the pathophysiology of neurodegenerative diseases that affect the subcortical structures of the basal ganglia in humans.HighlightsThe subcortical gray matter areas of macaque monkeys are reliably mapped by QSM, much as they are in humans.Combining T1w and QSM images improves the visualization and segmentation of white matter, cortical and subcortical structures in the macaque monkey.The proposed dual contrast TQ-SILiCON provides a similar image quality also in humans.TQ-SILiCON facilitates comparative and translational neuroscience studies investigating subcortical structures.

Anisotropic Modeling of Fibrous White Matter

2008 ◽  
Author(s):  
Rika M. Wright ◽  
K. T. Ramesh
Keyword(s):  
White Matter ◽  
Experimental Studies ◽  
Diffuse Axonal Injury ◽  
Strain Energy Function ◽  
Brain Structures ◽  
The United States ◽  
Cellular Level ◽  
Brain Deformation ◽  
Injury Mechanisms ◽  
The Brain

Traumatic brain injury (TBI) is a debilitating injury that affects more than 1.4 million people in the United States each year. Of the incidences of TBI, diffuse axonal injury (DAI) accounts for the second largest percentage of deaths. DAI is caused by inertial loads to the head, and it is characterized by damage to neurons. Despite the extensive research on DAI, the injury mechanisms associated with the pathology are still poorly understood. The crucial link between the inertial forces to the head at the macroscale and the resulting damage at the cellular level has yet to be explained. An integral step to understanding this coupling between mechanical forces and the functional damage of neurons is the development of an analytical model that accurately represents the mechanics of brain deformation under inertial loads. It has been noted in clinical and experimental studies that the most common injury location of DAI is within the deep white matter of the brain. Structures such as the splenium of the corpus callosum are cited as being highly susceptible to damage [1]. Although numerous brain tissue models have been proposed, few models account for the anisotropic nature of white matter in the brain. As a first step in developing an anisotropic model for white matter, the effect of the invariant terms in a strain energy function for white matter is analyzed.

scholarly journals A Brain to Spine Interface for Transferring Artificial Sensory Information

2019 ◽  
Author(s):  
Amol P. Yadav ◽  
Daniel Li ◽  
Miguel A. L. Nicolelis
Keyword(s):  
Sensory Information ◽  
Brain Structures ◽  
Dorsal Column ◽  
Subcortical Structures ◽  
Prosthetic Devices ◽  
Analog To Digital ◽  
Analog To Digital Conversion ◽  
Corticostriatal Plasticity ◽  
Dorsal Column Stimulation ◽  
The Brain

AbstractLack of sensory feedback is a major obstacle in the rapid absorption of prosthetic devices by the brain. While electrical stimulation of cortical and subcortical structures provides unique means to deliver sensory information to higher brain structures, these approaches require highly invasive surgery and are dependent on accurate targeting of brain structures. Here, we propose a semi-invasive method, Dorsal Column Stimulation (DCS) as a tool for transferring sensory information to the brain. Using this new approach, we show that rats can learn to discriminate artificial sensations generated by DCS and that DCS-induced learning results in corticostriatal plasticity. We also demonstrate a proof of concept brain-to-spine interface (BTSI), whereby tactile and artificial sensory information are decoded from the brain of an “encoder” rat, transformed into DCS pulses, and delivered to the spinal cord of a second “decoder” rat while the latter performs an analog-to-digital conversion during a tactile discrimination task. These results suggest that DCS can be used as an effective sensory channel to transmit prosthetic information to the brain or between brains, and could be developed as a novel platform for delivering tactile and proprioceptive feedback in clinical applications of brain-machine interfaces.

scholarly journals Can exercise make our children smarter?

2020 ◽  
Vol 10 (2) ◽  
Author(s):  
Nenad Stojiljković ◽  
Petar Mitić ◽  
Goran Sporiš
Keyword(s):  
White Matter ◽  
Brain Structure ◽  
Methodological Approach ◽  
Brain Structures ◽  
Structure And Function ◽  
Healthy Children ◽  
Cross Sectional ◽  
Brain Structure And Function ◽  
And Function ◽  
The Brain

Purpose. The aim of this study is to reveal the effects of exercise on the brain structure and function in children, and to analyze methodological approach applied in the researches of this topic. Methods. This literature review provides an overview of important findings in this fast growing research domain. Results from cross-sectional, longitudinal, and interventional studies of the influence of exercise on the brain structure and function of healthy children are reviewed and discussed. Results. The majority of researches are done as cross sectional studies based on the exploring correlation between the level of physical activity and characteristics of brain structure and function. Results of the studies indicate that exercise has positive correlation with improved cognition and beneficial changes to brain function in children. Physically active children have greater white matter integrity in several white matter tracts (corpus callosum, corona radiata, and superior longitudinal fasciculus), have greater volume of gray matter in the hippocampus and basal ganglia than their physically inactive counterparts. The longitudinal/interventional studies also showed that exercise (mainly aerobic) improve cognitive performance of children and causes changes observed on functional magnetic resonance imaging scans (fMRI) located in prefrontal and parietal regions. Conclusion. Previous researches undoubtable proved that exercise can make positive changes of the brain structures in children, specifically the volume of the hippocampus which is the center of learning and memory. Finally the researchers agree that the most influential type of exercise on changes of brain structure and functions are the aerobic exercises. 

scholarly journals Stereotactic system for accurately targeting deep brain structures in awake head-fixed mice

2019 ◽  
Author(s):  
Yonatan Katz ◽  
Michael Sokoletsky ◽  
Ilan Lampl
Keyword(s):  
Brain Structures ◽  
Nucleus Basalis ◽  
List Type ◽  
Time Alignment ◽  
Head Fixation ◽  
Stereotactic System ◽  
Mammillothalamic Tract ◽  
And Behavior ◽  
The Brain ◽  
Deep Brain

AbstractDeep brain nuclei, such as the amygdala, nucleus basalis, and locus coeruleus, play a crucial role in cognition and behavior. Nonetheless, acutely recording electrical activity from these structures in head-fixed awake rodents has been very challenging due to the fact that head-fixed preparations are not designed for stereotactic accuracy. We overcome this issue by designing the DeepTarget, a system for stereotactic head-fixation and recording, which allows for accurately directing recording electrodes or other probes into any desired location in the brain. We then validated it by performing intracellular recordings from optogenetically-tagged amygdalar neurons followed by histological reconstruction, which revealed that it is accurate and precise to within ∼100 μm. Moreover, in another group of mice we were able to target both the mammillothalamic tract and subthalamic nucleus. This approach can be adapted to any type of extracellular electrode, fiber optic or other probe in cases where high accuracy is needed in awake, head-fixed rodents.Highlights> The Deep Target, new system for accurately targeting deep nuclei in head-fixed animals for electrophysiology and optogenetics.> Accurate and precise to within 100 μm following a one-time alignment.> Validation: Opto-tagged Vm recordings in the amygdala of awake mice.> Validation: Targeting multiple deep brain structures in the same mouse.

scholarly journals EFFECT OF NEURODEGENERATIVE CHANGES IN THE BRAIN ON THE FORMATION OF THE DISEASE CLINICAL PICTURE IN PATIENTS WITH MULTIPLE SCLEROSIS

2013 ◽  
Vol 12 (3) ◽  
pp. 52-60 ◽  
Author(s):  
L. N. Prakhova ◽  
Ye. P. Magonov ◽  
A. G. Ilves ◽  
A. A. Bogdan ◽  
G. V. Kataeva ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Clinical Picture ◽  
Cerebral Atrophy ◽  
Brain Structures ◽  
Neurological Impairment ◽  
Disease Assessment ◽  
Control Group ◽  
Subcortical Structures ◽  
Severity Of Disability ◽  
The Brain

The aim of the study was to determine the relationship of global and regional cerebral atrophy and volume of demyelination lesions in the brain with a clinical picture in patients with multiple sclerosis (MS). The study involved 55 patients with MS. Control group included 22 healthy volunteers. Patients were divided into groups according to the severity of disability, the type and duration of disease. Assessment of general and regional atrophy was performed by post-process volumetric segmentation of MRI data, which was acquired at 3T Philips Achieva scanner. The post-processing was done with the FreeSurfer software. It is shown that in MS patients brain atrophy develops both by means of gray matter (including the cortex and subcortical structures), and white matter, along with demyelination. Global and regional atrophy is associated with the severity of disability of patients according to EDSS scale, but not with the duration and type of the disease. Neurodegenerative changes of brain structures evolve with different rates, have different intensity and determine the set of symptoms of neurological impairment and severity of disability, which indicates the presence of certain patterns of the process of atrophy in the brain, forming the clinical picture of the disease.

Regional, Directional, and Age-Dependent Properties of the Brain Undergoing Large Deformation

2002 ◽  
Vol 124 (2) ◽  
pp. 244-252 ◽  
Author(s):  
Michael T. Prange ◽  
Susan S. Margulies
Keyword(s):  
White Matter ◽  
Brain Tissue ◽  
Large Strain ◽  
Human Brain Tissue ◽  
Tissue Properties ◽  
Age Dependent ◽  
Autopsy Data ◽  
Degree Of Anisotropy ◽  
The Brain ◽  
Human Autopsy

The large strain mechanical properties of adult porcine gray and white matter brain tissues were measured in shear and confirmed in compression. Consistent with local neuroarchitecture, gray matter showed the least amount of anisotropy, and corpus callosum exhibited the greatest degree of anisotropy. Mean regional properties were significantly distinct, demonstrating that brain tissue is inhomogeneous. Fresh adult human brain tissue properties were slightly stiffer than adult porcine properties but considerably less stiff than the human autopsy data in the literature. Mixed porcine gray/white matter samples were obtained from animals at “infant” and “toddler” stages of neurological development, and shear properties compared to those in the adult. Only the infant properties were significantly different (stiffer) from the adult.

White matter lesion extension to automatic brain tissue segmentation on MRI

NeuroImage ◽  
2009 ◽  
Vol 45 (4) ◽  
pp. 1151-1161 ◽  
Author(s):  
Renske de Boer ◽  
Henri A. Vrooman ◽  
Fedde van der Lijn ◽  
Meike W. Vernooij ◽  
M. Arfan Ikram ◽  
...  
Keyword(s):  
White Matter ◽  
Brain Tissue ◽  
White Matter Lesion ◽  
Tissue Segmentation ◽  
Brain Tissue Segmentation ◽  
Lesion Extension

scholarly journals Semi-Supervised Learning in Medical MRI Segmentation: Brain Tissue with White Matter Hyperintensity Segmentation Using FLAIR MRI

2021 ◽  
Vol 11 (6) ◽  
pp. 720
Author(s):  
ZunHyan Rieu ◽  
JeeYoung Kim ◽  
Regina EY Kim ◽  
Minho Lee ◽  
Min Kyoung Lee ◽  
...  
Keyword(s):  
White Matter ◽  
Supervised Learning ◽  
Brain Tissue ◽  
Structural Changes ◽  
Brain Aging ◽  
High Reliability ◽  
White Matter Hyperintensity ◽  
Learning Method ◽  
Similarity Coefficients ◽  
Tissue Segmentation

White-matter hyperintensity (WMH) is a primary biomarker for small-vessel cerebrovascular disease, Alzheimer’s disease (AD), and others. The association of WMH with brain structural changes has also recently been reported. Although fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) provide valuable information about WMH, FLAIR does not provide other normal tissue information. The multi-modal analysis of FLAIR and T1-weighted (T1w) MRI is thus desirable for WMH-related brain aging studies. In clinical settings, however, FLAIR is often the only available modality. In this study, we thus propose a semi-supervised learning method for full brain segmentation using FLAIR. The results of our proposed method were compared with the reference labels, which were obtained by FreeSurfer segmentation on T1w MRI. The relative volume difference between the two sets of results shows that our proposed method has high reliability. We further evaluated our proposed WMH segmentation by comparing the Dice similarity coefficients of the reference and the results of our proposed method. We believe our semi-supervised learning method has a great potential for use for other MRI sequences and will encourage others to perform brain tissue segmentation using MRI modalities other than T1w.

scholarly journals Brain tissue segmentation based on MP2RAGE multi-contrast images in 7 T MRI

2018 ◽  
Author(s):  
Uk-Su Choi ◽  
Hirokazu Kawaguchi ◽  
Yuichiro Matsuoka ◽  
Tobias Kober ◽  
Ikuhiro Kida
Keyword(s):  
Processing Time ◽  
The Other ◽  
Brain Atlas ◽  
7 Tesla ◽  
Subcortical Structures ◽  
Tissue Segmentation ◽  
Rapid Acquisition ◽  
Segmentation Approach ◽  
The Brain ◽  
Brain Tissues

AbstractWe proposed a method for segmentation of brain tissues––gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF)—using multi-contrast images, including a T1 map and a uniform T1-weighted image, from a magnetization-prepared 2 rapid acquisition gradient echoes (MP2RAGE) sequence at 7 Tesla. The proposed method was evaluated with respect to the processing time and the similarity of the segmented masks of brain tissues with those obtained using FreeSurfer, FSL, and SPM12. The processing time of the proposed method (28 ± 0 s) was significantly shorter than those of FSL and SPM12 (444 ± 4 s and 159 ± 2 s for FSL and SPM12, respectively). In the similarity assessment, the tissue mask of the brain obtained by the proposed method showed higher consistency with those obtained by FSL than with those obtained by SPM12. The proposed method misclassified the subcortical structures and large vessels since it is based on the intensities of multi-contrast images obtained using MP2RAGE, which uses a similar segmentation approach as FSL but is not based on a template image or a parcellated brain atlas, which are used for FreeSurfer and SPM12, respectively. However, the proposed method showed good segmentation in the cerebellum and WM in the medial part of the brain in comparison with the other methods. Thus, because the proposed method using different contrast images of MP2RAGE sequence showed the shortest processing time and similar segmentation ability as the other methods, it may be useful for both neuroimaging research and clinical diagnosis.

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