Giannoni, Luca;
(2020)
Hyperspectral imaging of the haemodynamic and metabolic states of the exposed cortex.
Doctoral thesis (Ph.D), UCL (University College London).
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Abstract
A hyperspectral imaging (HSI) system to measure and quantify in vivo haemodynamic and metabolic signals from the exposed cerebral cortex of small animals was designed, developed and investigated in this thesis. Imaging brain tissue at multiple narrow wavelength bands in the visible and near-infrared (NIR) range allows one not only to monitor cerebral oxygenation and haemodynamics via mapping of haemoglobin concentration changes, but also to directly target the spatial quantification of cerebral metabolic activity via measurement of the redox states of mitochondrial cytochrome-c-oxidase (CCO). Having both these sets of information in vivo at high resolution on the exposed cortex can provide impactful insight on brain physiology and can help validate corresponding data acquired non-invasively using broadband near-infrared spectroscopy (bNIRS). Several designs and HSI configurations were assessed and compared, including different customised benchtop setups. In the end, a bespoke spectral-scanning HSI system called hNIR, using a supercontinuum laser coupled with a rotating Pellin-Broca prism and a scientific complementary metal-oxide semiconductor (sCMOS) camera, was built, characterised and validated on liquid optical phantoms. In addition, an in-house Monte Carlo (MC) framework for simulating HSI of the haemodynamic and metabolic states of the exposed cortex was also developed using an open-source MC code package (Mesh-based Monte Carlo) and integrated with hNIR, for aiding image reconstruction and enhance quantification, as well as to run computational investigations on the performances of HSI for brain haemodynamic and metabolic monitoring. hNIR was finally applied in vivo on the exposed cerebral cortex of three mice during different levels of hyperoxic and hypoxic stimulation, demonstrating its capability to retrieve high resolution and accurate maps of the relative changes in the concentrations of oxyhaemoglobin (HbO₂), deoxyhaemoglobin (HHb) and the oxidative state of CCO (oxCCO).
Type: | Thesis (Doctoral) |
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Qualification: | Ph.D |
Title: | Hyperspectral imaging of the haemodynamic and metabolic states of the exposed cortex |
Event: | UCL (University College London) |
Open access status: | An open access version is available from UCL Discovery |
Language: | English |
Additional information: | Copyright © The Author 2020. Original content in this thesis is licensed under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) Licence (https://creativecommons.org/licenses/by/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Med Phys and Biomedical Eng |
URI: | https://discovery.ucl.ac.uk/id/eprint/10113539 |
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