The cerebral angiome: High resolution MicroCT imaging of the whole brain cerebrovasculature in female and male mice

NeuroImage, Journal Year: 2019, Volume and Issue: 202, P. 116109 - 116109

Published: Aug. 22, 2019

Language: Английский

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Voxelized simulation of cerebral oxygen perfusion elucidates hypoxia in aged mouse cortex

PLoS Computational Biology, Journal Year: 2021, Volume and Issue: 17(1), P. e1008584 - e1008584

Published: Jan. 28, 2021

Departures of normal blood flow and metabolite distribution from the cerebral microvasculature into neuronal tissue have been implicated with age-related neurodegeneration. Mathematical models informed by spatially temporally distributed neuroimage data are becoming instrumental for reconstructing a coherent picture pathological oxygen delivery throughout brain. Unfortunately, current mathematical exchange become excessively large in size. They further suffer boundary effects due to incomplete or physiologically inaccurate computational domains, numerical instabilities enormous length scale differences, convergence problems associated condition number deterioration at fine mesh resolutions. Our proposed simple finite volume discretization scheme microperfusion simulations does not require expensive generation leading critical benefit that it drastically reduces matrix size bandwidth coupled transfer problem. The compact problem formulation yields rapid stable convergence. Moreover, can effectively be suppressed generating very replica cortical microcirculation silico using an image-based cerebrovascular network synthesis algorithm, so boundaries perfusion far removed regions interest. Massive over sizeable portions cortex feature resolution down micron tractable even modest computer resources. feasibility accuracy novel method is demonstrated validated vivo cohorts young aged mice. quantify steep gradients near penetrating vessels point towards changes might cause neurodegeneration brains. This research aims explain mechanistic interactions between anatomical structures how they change diseases age. Rigorous quantification significant interest because aide search imaging biomarkers dementia Alzheimer’s disease.

Language: Английский

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Mathematical synthesis of the cortical circulation for the whole mouse brain—part II: Microcirculatory closure

Microcirculation, Journal Year: 2021, Volume and Issue: 28(5)

Published: Feb. 22, 2021

Recent advancements in multiphoton imaging and vascular reconstruction algorithms have increased the amount of data on cerebrovascular circulation for statistical analysis hemodynamic simulations. Experimental observations offer fundamental insights into capillary network topology but mainly within a narrow field view typically spanning small fraction cortical surface (less than 2%). In contrast, larger-resolution modalities, such as computed tomography (CT) or magnetic resonance (MRI), whole-brain coverage capture only larger blood vessels, overlooking microscopic bed. To integrate acquired at multiple length scales with different neuroimaging modalities to reconcile brain-wide macroscale information microscale data, we developed method synthesizing hemodynamically equivalent networks entire cerebral circulation. This computational approach is intended aid quantification patterns flow metabolism brain. part I, described mathematical framework image-guided generation synthetic covering large arteries from circle Willis through pial leading back venous sinuses. Here II, introduce novel procedures creating microcirculatory closure that mimics realistic We demonstrate our capability synthesize whose morphometrics match empirical graphs three independent state-of-the-art laboratories using image acquisition protocols. also successfully synthesized twelve complete mouse brain hemisphere suitable performing Synthetic arterial microvascular allow predictions. Simulations across all will potentially illuminate organ-wide supply metabolic functions are inaccessible models reconstructed limited spatial coverage.

Language: Английский

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Analysis of Brain Tissue Poroelastic Properties Using Multiscale Modelling

IIUM Engineering Journal, Journal Year: 2025, Volume and Issue: 26(1), P. 437 - 449

Published: Jan. 10, 2025

Mathematical models are developed to further understand ischaemic stroke formation and achieve treatment effectiveness. The existing poroelastic model of the brain assumed as a homogenized structure with uniform capillary distribution. This paper describes use multiscale modeling technique known asymptotic expansion homogenization (AEH) derive new tissue. consists governing macroscale effective parameters determined from microscale cell equations. equations solved on representative volume element (RVE) comprising tissue embedded capillary. Here, effect tortuosity radius parameters, which hydraulic conductivity interstitial space (K G), homogenous Biot's coefficient blood (?c? ?t?), Young's modulus Poisson's ratio investigated. From results, it is found that percentage difference K 97.98% increasing tortuosity, suggests significantly influenced by shape In contrast, G only 0.25%, showing unaffected Meanwhile, ?c? ?t decrease increase respectively. Both E ? not affected for each just 0.14% 0.03%, terms radius, increases decreases radius. while ?t? shows opposite trend. differences 18.26% 14.55% observed E? ?, respectively, implying both conclusion, including capillaries in affects parameters. Hence, important properties capillary, size, should be carefully emphasized so accurate findings can obtained when solving brain. ABSTRAK: Model matematik dibangunkan untuk mendapatkan pemahaman lanjut tentang pembentukan strok iskemia supaya keberkesanan rawatan dapat dicapai. poroelastik otak yang sedia ada menganggap sebagai struktur homogen dengan taburan kapilari seragam. Makalah ini menerangkan penggunaan teknik pemodelan multiskala dikenali penghomogenan pengembangan asimtotik (PPA) memperoleh baharu tisu otak. terdiri daripada satu set skala makro pentadbir parameter berkesan ditentukan persamaan sel mikro. Persamaan mikro diselesaikan pada unsur isipadu perwakilan tertanam. Di sini, kesan kelikuan dan jejari berkesan, iaitu kekonduksian hidraulik ruang celahan pekali Biot bagi darah Young (E) nisbah Poisson (?), akan diselidiki. Daripada keputusan diperoleh, didapati perbezaan peratusan ialah peningkatan kelikuan, menunjukkan bahawa dipengaruhi oleh bentuk secara signifikan. Manakala hanyalah ia tidak kelikuan. Sementara itu, masing-masing menurun meningkat Kedua-dua terjejas ketara kerana setiap hanya 0.03%. Dari segi pula, bertambah berkurangan pertambahan jejari. ?c jejari, manakala sebaliknya. Peratusan diperhatikan kedua-dua kapilari. Kesimpulannya, kemasukan dalam mempunyai terhadap berkesan. Oleh sifat penting termasuk saiz harus ditekankan teliti penemuan tepat boleh diperolehi apabila menyelesaikan

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A new framework for assessing subject-specific whole brain circulation and perfusion using MRI-based measurements and a multi-scale continuous flow model

PLoS Computational Biology, Journal Year: 2019, Volume and Issue: 15(6), P. e1007073 - e1007073

Published: June 25, 2019

A large variety of severe medical conditions involve alterations in microvascular circulation. Hence, measurements or simulation circulation and perfusion has considerable clinical value can be used for diagnostics, evaluation treatment efficacy, surgical planning. However, the accuracy traditional tracer kinetic one-compartment models is limited due to scale dependency. As a remedy, we propose invariant mathematical framework simulating whole brain perfusion. The suggested based on segmentation anatomical geometry down imaging voxel resolution. Large vessels arterial venous network are identified from time-of-flight (ToF) quantitative susceptibility mapping (QSM). Macro-scale flow large-vessel-network accurately modelled using Hagen-Poiseuille equation, whereas capillary treated as two-compartment porous media flow. coupled with micro-scale by spatially distributing support function terminal endings. Perfusion defined transition fluid compartment. We demonstrate propagation realistic geometric model human brain, where comprises distinct areas grey white matter, well vascular network. Our proposed an accurate viable alternative compartment models, high relevance also restoration field parameters applications.

Language: Английский

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