A5062714017- Advanced Fluorescence Microscopy Techniques
- Optical Coherence Tomography Applications
- Optical Imaging and Spectroscopy Techniques
- Cell Image Analysis Techniques
- Photoacoustic and Ultrasonic Imaging
- Advanced MRI Techniques and Applications
- Traumatic Brain Injury and Neurovascular Disturbances
- Coronary Interventions and Diagnostics
- Diffusion and Search Dynamics
- Functional Brain Connectivity Studies
- Advanced Neuroimaging Techniques and Applications
- Lipid Membrane Structure and Behavior
- Neurological Disease Mechanisms and Treatments
- Neuroinflammation and Neurodegeneration Mechanisms
- Angiogenesis and VEGF in Cancer
- Fetal and Pediatric Neurological Disorders
- Olfactory and Sensory Function Studies
- MRI in cancer diagnosis
- Prostate Cancer Treatment and Research
- Thermal Regulation in Medicine
- Retinal Imaging and Analysis
- Thermoregulation and physiological responses
- Digital Imaging for Blood Diseases
- Cardiovascular Disease and Adiposity
- Cerebrovascular and Carotid Artery Diseases
Université du Québec à Montréal
2021-2024
Département d'Informatique
2022
University of Oxford
2019-2021
Polytechnique Montréal
2011-2019
Multidisciplinary Digital Publishing Institute (Switzerland)
2017
Umeå University
2017
Royal Brompton Hospital
2017
Imperial College London
2017
Osaka City University
2017
Brunel University of London
2017
The blood oxygenation level-dependent (BOLD) contrast is widely used in functional magnetic resonance imaging (fMRI) studies aimed at investigating neuronal activity. However, the BOLD signal reflects changes volume and rather than activity per se. Therefore, understanding transformation of microscopic vascular behavior into macroscopic signals foundation physiologically informed noninvasive neuroimaging. Here, we use oxygen-sensitive two-photon microscopy to measure BOLD-relevant...
An automated massive histology setup combined with an optical coherence tomography (OCT) microscope was used to image a total of n=5 whole mouse brains. Each acquisition generated dataset thousands OCT volumetric tiles at sampling resolution 4.9×4.9×6.5 μm. This paper describes techniques for reconstruction and segmentation the sliced In addition measured reflectivity, single scattering photon model compute attenuation coefficients within each tissue slice. Average brain templates were both...
Optical coherence tomography (OCT) has recently been used to produce 3D angiography of microvasculature and blood flow maps large vessels in the rodent brain in-vivo. However, use this optical method for study cerebrovascular disease not fully explored. Recent developments neurodegenerative diseases linked common cardiovascular risk factors hinting at a vascular hypothesis development latter. Tools studying cerebral myogenic tone vasculature have thus far either highly invasive or required...
Given known correlations between vascular health and cognitive impairment, the development of tools to image microvasculature in whole brain could help investigate these correlations. We explore feasibility using an automated serial two-photon microscope fluorescent gelatin-filled rodent brains three-dimensions (3-D) with goal carrying group studies. Vascular density (VD) was computed automatic segmentation combined coregistration techniques build a group-level metric brain. Focusing on...
There is a need to improve the treatment of prostate cancer (PCa) and reduce side effects. Vascular-targeted photodynamic therapy (VTP) focal for low-risk low-volume localised PCa, which rapidly disrupts targeted tumour vessels. interest in expanding use VTP higher-risk disease. Tumour vasculature characterised by vessel immaturity, increased permeability, aberrant branching inefficient flow. FRT alters microenvironment promotes transient 'vascular normalisation'. We hypothesised that...
An automated dual-resolution serial optical coherence tomography (2R-SOCT) scanner is developed. The histology system combines a low-resolution ( 25 μm/voxel ) 3× OCT with high-resolution 1.5 40× to acquire whole mouse brains at low resolution and target specific regions of interest (ROIs) high resolution. ROIs positions are selected either manually by the microscope operator or using an ROI positioning selection algorithm. Additionally, multimodal multiresolution registration pipeline...
Normal aging is accompanied by structural changes in the heart architecture. To explore this remodeling, we used a serial optical coherence tomography scanner to image entire mouse hearts at micron scale resolution. Ex vivo of 7 young (4 months) and 5 old (24 C57BL/6 mice were acquired with imaging platform. OCT myocardium revealed myofiber orientation changing linearly from endocardium epicardium. In mice, rate change was lower when compared while average volume significantly larger...
An automated serial histology setup combining optical coherence tomography (OCT) imaging with vibratome sectioning was used to image eight wild type mouse brains. The datasets resulted in thousands of volumetric tiles resolved at a voxel size (4.9×4.9×6.5) μm3 stitched back together give three-dimensional map the brain from which template OCT obtained. To assess deformation caused by tissue sectioning, reconstruction algorithms, and fixation, were compared both vivo ex magnetic resonance...
Atherosclerotic cardiovascular diseases are characterized by the formation of a plaque in arterial wall. Intravascular ultrasound (IVUS) provides high-resolution images allowing delineation atherosclerotic plaques. When combined with near infrared fluorescence (NIRF), can also be studied at molecular level large variety biomarkers. In this work, we present system enabling automated volumetric histology imaging excised aortas that spatially correlate results IVUS/NIRF lipid-rich atheroma...
The following topics are dealt with: medical image processing; learning (artificial intelligence); segmentation; biomedical MRI; brain; neural nets; classification; diseases; computerised tomography; and neurophysiology.
<ns3:p>Single particle tracking (SPT) is one of the most widely used tools in optical microscopy to evaluate mobility a variety situations, including cellular and model membrane dynamics. Recent technological developments, such as Interferometric Scattering microscopy, have allowed recording long, uninterrupted single trajectories at kilohertz framerates. The resulting data, where particles are continuously detected do not displace much between observations, thereby require complex linking...
Single-molecule localization microscopy (SMLM) is a super-resolution imaging technique developed to image structures smaller than the diffraction limit. This modality results in sparse and non-uniform sets of localized blinks that need be reconstructed obtain representation tissue. In this paper, we explore use Noise2Noise (N2N) paradigm reconstruct SMLM images. an denoising where neural network trained with only pairs noisy realizations data instead using noisy/clean images, as performed...
Previous studies have shown that the optical coherence tomography (OCT) signal in white matter (WM) is affected by WM fiber bundles orientation with respect to microscope's axis. In this paper, we aim exploit contrast mechanism generate a multi-orientation representation of microstructure whole mouse brains. To achieve this, serial blockface histology set-up has been developed combined spectral domain OCT equipped long-range 10x magnification objective, achieving near isotropic resolution 3...
Optical coherence tomography (OCT) has shown an affinity for imaging white matter using intrinsic signals. Combined with automated vibratome and mosaic imaging, serial blockface histology (SBH) can yield whole-brain images at high resolution. A current drawback of SBH is the lack real-time information that complicates localization brain structures during imaging. To address this, imaged slices be registered to a pre-existing 3D volume provide more contextual acquisition. image registration...
A whole rodent brain was imaged using an automated massive histology setup and Optical Coherence Tomography (OCT) microscope. Thousands of OCT volumetric tiles were acquired, each covering a size about 2.5x2.5x0.8 mm3 with sampling resolution 4.9x4.9x6.5 microns. This paper shows the techniques for reconstruction, attenuation compensation segmentation sliced brains. The tile positions within mosaic evaluated displacement model motorized stage pairwise coregistration. Volume blending then...
A combined serial OCT/confocal scanner was designed to image large sections of biological tissues at microscopic resolution. Serial imaging organs embedded in agarose blocks is performed by cutting through tissue using a vibratome which sequentially cuts slices order reveal new image, overcoming limited light penetration encountered microscopy. Two linear stages allow moving the with respect microscope objective, acquiring 2D grid volumes (1x1x0.3 mm) OCT and images (1x1mm) confocal arm....
In this study, an automated serial two-photon microscope was used to image a fluorescent gelatin filled rodent's brain in 3D. A method compute vascular density using automatic segmentation combined with coregistration techniques build group-level vasculature metrics. By studying the medial prefrontal cortex and hippocampal formation of 3 age groups (2, 4.5 8 months old), we compared for both WT Alzheimer model transgenic (APP/PS1). We observe loss caused by ageing process propose further...
What are the properties of cortical microvascular oxygenation that allow uninterrupted oxygen delivery to all tissue regions in a very dynamic and energetically demanding brain? In this work we applied multimodal microscopic imaging intravascular partial pressure O2 (PO2) blood flow complemented by numerical modeling address question mouse cerebral cortex. Our measurements show at baseline level neuronal activity small arterioles responsible for significant extraction, while most remaining...
What is the organization of cerebral microvascular oxygenation and morphology that allows adequate tissue at different activity levels? We addressed this question in mouse cortex using Two-Photon Microscopy imaging intravascular O2 partial pressure Optical Coherence Tomography blood flow combined with numerical modeling. Surprisingly, our measurements show parenchymal arterioles are responsible for 50% extracted baseline majority remaining exchange takes place within first few capillary...
We have developed a model of BOLD-fMRI from first principles using two-photon microscopic measurements cerebrovascular physiology. The was validated against experimental BOLD at several levels. Our bottom up approach predicted new phenomenon: the folding cortical surface produces variations in signal corresponding to 40% amplitude generated by neuronal activation. This prediction further experimentally with human measurements, confirming predictive power our approach.
To obtain an accurate representation of a brain structural connectivity, diffusion MRI and fiber tracking depend on good understanding white matter structures. Although the methods work well when performed in single orientation bundles, most are limited more complex cases, especially to take into account crossing, fanning, kissing fibers. A recent international challenge concluded that algorithms generated 4–5 times false positive tracks than true average. This was attributed large part lack...