scholarly journals Characterization of spatial dynamics of fMRI data in white matter using diffusion-informed white matter harmonics

2020 ◽  
Author(s):  
Hamid Behjat ◽  
Iman Aganj ◽  
David Abramian ◽  
Anders Eklund ◽  
Carl-Fredrik Westin

ABSTRACTIn this work, we leverage the Laplacian eigenbasis of voxel-wise white matter (WM) graphs derived from diffusionweighted MRI data, dubbed WM harmonics, to characterize the spatial structure of WM fMRI data. By quantifying the energy content of WM fMRI data associated with subsets of WM harmonics across multiple spectral bands, we show that the data exhibits notable subtle spatial modulations under functional load that are not manifested during rest. WM harmonics provide a novel means to study the spatial dynamics of WM fMRI data, in such way that the analysis is informed by the underlying anatomical structure.

Author(s):  
Amal Alzain ◽  
Suhaib Alameen ◽  
Rani Elmaki ◽  
Mohamed E. M. Gar-Elnabi

This study concern to characterize the brain tissues to ischemic stroke, gray matter, white matter and CSF using texture analysisto extract classification features from CT images. The First Order Statistic techniques included sevenfeatures. To find the gray level variation in CT images it complements the FOS features extracted from CT images withgray level in pixels and estimate the variation of thesubpatterns. analyzing the image with Interactive Data Language IDL software to measure the grey level of images. The results show that the Gray Level variation and   features give classification accuracy of ischemic stroke 97.6%, gray matter95.2%, white matter 97.3% and the CSF classification accuracy 98.0%. The overall classification accuracy of brain tissues 97.0%.These relationships are stored in a Texture Dictionary that can be later used to automatically annotate new CT images with the appropriate brain tissues names.


2019 ◽  
Vol 15 (7) ◽  
pp. P207-P209
Author(s):  
Oriol Grau-Rivera ◽  
Grégory Operto ◽  
Carles Falcon ◽  
Raffaele Cacciaglia ◽  
Gonzalo Sánchez-Benavides ◽  
...  

1995 ◽  
Vol 49 (10) ◽  
pp. 1516-1524 ◽  
Author(s):  
Alex O. Salnick ◽  
Werner Faubel

Fourier transform infrared photoacoustic spectroscopy (FT-IR/PAS) has proved to be a useful tool for nondestructive testing of copper corrosion layer (patina) formed in the atmosphere. The samples cut from a piece of the roof of the Stockholm City Hall were examined without any additional pretreatment. The components of the patina—brochantite Cu4(OH)6SO4, antlerite Cu3(OH)4SO4, and basic cupric carbonate Cu2CO3(OH)6 · H2O—as well as some other minerals were identified. The photothermal beam deflection (PBD) method was used for independent photoacoustic characterization of the samples. The depth profiling capability of FT-IR/PAS was used to determine the degree of photoacoustic saturation of the spectral bands and to evaluate the depth distribution of the main patina components. The technique thus compares favorably with more common approaches of patina examination which are more expensive and require special sample preparation.


Neuroscience ◽  
2016 ◽  
Vol 333 ◽  
pp. 140-150 ◽  
Author(s):  
Zsófia Richter ◽  
József Janszky ◽  
György Sétáló ◽  
Réka Horváth ◽  
Zsolt Horváth ◽  
...  

2017 ◽  
Vol 134 (3) ◽  
pp. 383-401 ◽  
Author(s):  
Gijsbert P. van Nierop ◽  
Marvin M. van Luijn ◽  
Samira S. Michels ◽  
Marie-Jose Melief ◽  
Malou Janssen ◽  
...  

2019 ◽  
Author(s):  
chiara casella ◽  
Claudia Metzler-Baddeley ◽  
Derek Jones ◽  
Ilona Lipp

Huntington’s disease (HD) is a genetic neurodegenerative disorder, characterised by atrophy of the neostriatum, and cortical grey matter abnormalities. White matter (WM) alterations have recently been identified as a relevant pathophysiological feature of HD, but the etiology of WM degeneration, and its role in disease pathogenesis and progression remain unclear. An increasing body of research suggests that WM changes in HD are due to alterations in myelin-associated biological processes at the cellular and molecular level. This review first discusses evidence from neurochemical studies lending support to the ‘De-myelination hypothesis’ of HD, and pointing towards a role for aberrant myelination and changes in oligodendrocytes in HD WM. Next, evidence from neuroimaging studies is reviewed, the limitations of the described methodologies are discussed and suggested interpretations of findings from published studies are challenged. Although our understanding of HD-associated pathological changes in the brain will increasingly rely on neuroimaging techniques, the shortcomings of these methodologies must not be forgotten. Advances in MRI techniques and tissue modeling will enable a better characterization of the biological properties of WM microstructure, and will allow more specific monitoring of longitudinal changes noninvasively. This, in turn, will provide insight into disease pathogenesis and progression and facilitate the identification of disease-related biomarkers and the specification of outcome measures in clinical trials.


2019 ◽  
Vol 28 (1) ◽  
pp. 96-110
Author(s):  
Marija Podļesnaja ◽  
Mara Pilmane ◽  
Modris Ciems

Meniscus is a fibrocartilaginous anatomical structure that realizes complicated biomechanical functions in the knee joint. However, no comparative morphology studies have been done on different species and conditions regarding the meniscus. Thus, the aim of our pilot study was to compare the morphology of traumatized and aged human and healthy deer meniscus to reveal the tissue ground, growth, degeneration, cell death and inflammation factors. The study included surgery materials from one deer and two humans. Biotin-streptavidin immunohistochemistry was performed for detection of tissue TGFβ1, MMP2, MMP9, collagen I, caspase, Il-1, Il-6, Il-10. The results were evaluated semiquantitatively. An abundant number of Collagen I positive cells were detected in the disordered human meniscus but not in the deer one. TGFβ1 was seen in numerous to abundant number of cells in all the three cases. MMPs and caspase were distributed with numerous to abundant cells in both human and deer meniscus. Numerous to abundant cells of traumatized and aged human menisci showed IL-1 and IL-6, while the deer meniscus demonstrated cytokine expression in a moderate number of cells only in limited zones. The traumatized human meniscus possessed an abundant number of IL-10 positive cells, while the deer and the aged human meniscus showed mainly a moderate number of IL-10 cells with some elevation of cytokine in superficial and deepest layers of the meniscus.


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