{"id":{"repo_id":"sherbrooke","oai_identifier":"oai:usherbrooke.scholaris.ca:11143/10259"},"canonical_url":"https://search.dev.ndltd.org/etd/sherbrooke/oai:usherbrooke.scholaris.ca:11143/10259","repository":{"repo_id":"sherbrooke","name":"Université de Sherbrooke","base_url":"https://usherbrooke.scholaris.ca/server/oai/request"},"display":{"title":"Segmentation et extraction de caractéristiques des vaisseaux sanguins cérébraux à l'aide de l'IRM","abstract":"The neurovascular coupling is a growing field; it studies the effects of cerebral activity on the behaviour of cerebral blood flow (CBF) and the blood vessels themselves. With the help of magnetic resonance imaging (MRI), it is possible to obtain images such as susceptibility weighted imaging (SWI) to see the veins or time-of-flight magnetic resonance angiography (TOF MRA) to visualize the arteries. These images allow having a structural representation of vessels in the brain. This thesis presents a method to segment blood vessels from structural images and extract their features. Using the segmentation mask, it is possible to calculate the diameter of the vessels as well as their length. With the help of such automatic segmentation tools, we conducted a study to analyze the behaviour of blood vessels during neuronal activities. Due to visual stimulation, we have acquired two images; one at rest and the other with stimulation. We compare the diameter in each of the images and obtain vasodilation in millimeters, but also as a percentage in each voxel. We also calculated the distance between the activation site and each voxel to see the magnitude of the vasodilation function of the distance. All this provides a better understanding of the vascular system of the human brain.","abstract_html":"The neurovascular coupling is a growing field; it studies the effects of cerebral activity on the behaviour of cerebral blood flow (CBF) and the blood vessels themselves. With the help of magnetic resonance imaging (MRI), it is possible to obtain images such as susceptibility weighted imaging (SWI) to see the veins or time-of-flight magnetic resonance angiography (TOF MRA) to visualize the arteries. These images allow having a structural representation of vessels in the brain. This thesis presents a method to segment blood vessels from structural images and extract their features. Using the segmentation mask, it is possible to calculate the diameter of the vessels as well as their length. With the help of such automatic segmentation tools, we conducted a study to analyze the behaviour of blood vessels during neuronal activities. Due to visual stimulation, we have acquired two images; one at rest and the other with stimulation. We compare the diameter in each of the images and obtain vasodilation in millimeters, but also as a percentage in each voxel. We also calculated the distance between the activation site and each voxel to see the magnitude of the vasodilation function of the distance. All this provides a better understanding of the vascular system of the human brain.","abstract_has_math":false,"creators":["Bizeau, Alexandre"],"institution":"Université de Sherbrooke","degree_name":"M. Sc.","degree_level":"Maîtrise","degree_discipline":"Sciences des radiations et imagerie biomédicale","degree_department":null,"school":null,"contributors":[],"advisors":["Whittingstall, Kevin","Descoteaux, Maxime","Bocti, Christian"],"committee_chairs":[],"committee_members":[],"year":2017,"date_issued":"2017","date_published":"2017","updated_at":"2026-07-27T21:07:45Z","subjects":["Temps de vol (Time-of-flight)","Diamètre","Stimulation","Volume sanguin cérébral","Flux sanguin cérébral","Time-of-flight","Diameter","Cerebral blood volume","Cerebral blood flow"],"languages":["fr","en"],"rights":[],"rights_urls":["http://creativecommons.org/licenses/by-nc-nd/2.5/ca/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11143/10259","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Whittingstall, Kevin","Descoteaux, Maxime","Bocti, Christian"]},{"key":"dc:creator","label":"Author","values":["Bizeau, Alexandre"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2017-03-24T14:16:14Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2017-03-24T14:16:14Z"]},{"key":"dc:date.issued","label":"Date","values":["2017"]},{"key":"dc:publisher","label":"Institution","values":["Université de Sherbrooke"]},{"key":"dc:type","label":"Dc Type","values":["Mémoire de maîtrise"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Sciences des radiations et imagerie biomédicale"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Maîtrise"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M. 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With the help of magnetic resonance imaging (MRI), it is possible to obtain images such as susceptibility weighted imaging (SWI) to see the veins or time-of-flight magnetic resonance angiography (TOF MRA) to visualize the arteries. These images allow having a structural representation of vessels in the brain. This thesis presents a method to segment blood vessels from structural images and extract their features. Using the segmentation mask, it is possible to calculate the diameter of the vessels as well as their length. With the help of such automatic segmentation tools, we conducted a study to analyze the behaviour of blood vessels during neuronal activities. Due to visual stimulation, we have acquired two images; one at rest and the other with stimulation. We compare the diameter in each of the images and obtain vasodilation in millimeters, but also as a percentage in each voxel. We also calculated the distance between the activation site and each voxel to see the magnitude of the vasodilation function of the distance. All this provides a better understanding of the vascular system of the human brain.","Le couplage neuro-vasculaire est un domaine grandissant. Ce dernier étudie les effets de l’activité cérébrale sur le comportement du flux sanguin cérébral (cerebral blood flow, CBF) et sur le flux des vaisseaux sanguins. Avec l’aide de l’imagerie par résonance magnétique (IRM), il est possible d’obtenir des images comme les images pondérées par susceptibilité (susceptibility weighted imaging, SWI) pour voir les veines ou bien avec des images de temps de vol par angiographie (time-of-flight magnetic resonance angiography, TOF MRA) pour imager les artères. Ces images permettent d’avoir une représentation structurelle des vaisseaux dans le cerveau. Ce mémoire présente une méthode permettant la segmentation des vaisseaux sanguins à partir d’images structurelles afin d’en extraire les caractéristiques. En utilisant le masque de segmentation, il est possible de calculer le diamètre des vaisseaux ainsi que leur longueur. Avec l’aide de tels outils de segmentation automatique, nous avons conduit une étude permettant d’analyser le comportement des vaisseaux sanguins lors d’activités neuronales. Grâce à une stimulation visuelle, nous avons fait l’acquisition de deux images; la première dite au repos et la seconde avec stimulation. Nous avons pu comparer le diamètre dans chacune des images et ainsi obtenir la vasodilatation en millimètre, mais également en pourcentage, et cela pour chaque voxel. Nous avons également calculé la distance entre le site d’activation et un voxel pour observer l’amplitude de la vasodilatation en fonction de la distance. Tout ceci permet d’avoir une meilleure compréhension du système vasculaire du cerveau humain."]},{"key":"dc:title","label":"Title","values":["Segmentation et extraction de caractéristiques des vaisseaux sanguins cérébraux à l'aide de l'IRM"]}]}],"canonical_facts":{"dc:contributor.advisor":["Whittingstall, Kevin","Descoteaux, Maxime","Bocti, Christian"],"dc:creator":["Bizeau, Alexandre"],"dc:date.accessioned":["2017-03-24T14:16:14Z"],"dc:date.available":["2017-03-24T14:16:14Z"],"dc:date.issued":["2017"],"dc:description.abstract":["The neurovascular coupling is a growing field; it studies the effects of cerebral activity on the behaviour of cerebral blood flow (CBF) and the blood vessels themselves. With the help of magnetic resonance imaging (MRI), it is possible to obtain images such as susceptibility weighted imaging (SWI) to see the veins or time-of-flight magnetic resonance angiography (TOF MRA) to visualize the arteries. These images allow having a structural representation of vessels in the brain. This thesis presents a method to segment blood vessels from structural images and extract their features. Using the segmentation mask, it is possible to calculate the diameter of the vessels as well as their length. With the help of such automatic segmentation tools, we conducted a study to analyze the behaviour of blood vessels during neuronal activities. Due to visual stimulation, we have acquired two images; one at rest and the other with stimulation. We compare the diameter in each of the images and obtain vasodilation in millimeters, but also as a percentage in each voxel. We also calculated the distance between the activation site and each voxel to see the magnitude of the vasodilation function of the distance. All this provides a better understanding of the vascular system of the human brain.","Le couplage neuro-vasculaire est un domaine grandissant. Ce dernier étudie les effets de l’activité cérébrale sur le comportement du flux sanguin cérébral (cerebral blood flow, CBF) et sur le flux des vaisseaux sanguins. Avec l’aide de l’imagerie par résonance magnétique (IRM), il est possible d’obtenir des images comme les images pondérées par susceptibilité (susceptibility weighted imaging, SWI) pour voir les veines ou bien avec des images de temps de vol par angiographie (time-of-flight magnetic resonance angiography, TOF MRA) pour imager les artères. Ces images permettent d’avoir une représentation structurelle des vaisseaux dans le cerveau. Ce mémoire présente une méthode permettant la segmentation des vaisseaux sanguins à partir d’images structurelles afin d’en extraire les caractéristiques. En utilisant le masque de segmentation, il est possible de calculer le diamètre des vaisseaux ainsi que leur longueur. Avec l’aide de tels outils de segmentation automatique, nous avons conduit une étude permettant d’analyser le comportement des vaisseaux sanguins lors d’activités neuronales. Grâce à une stimulation visuelle, nous avons fait l’acquisition de deux images; la première dite au repos et la seconde avec stimulation. Nous avons pu comparer le diamètre dans chacune des images et ainsi obtenir la vasodilatation en millimètre, mais également en pourcentage, et cela pour chaque voxel. Nous avons également calculé la distance entre le site d’activation et un voxel pour observer l’amplitude de la vasodilatation en fonction de la distance. Tout ceci permet d’avoir une meilleure compréhension du système vasculaire du cerveau humain."],"dc:identifier.uri":["http://hdl.handle.net/11143/10259"],"dc:language.iso":["fr","en"],"dc:publisher":["Université de Sherbrooke"],"dc:rights.uri":["http://creativecommons.org/licenses/by-nc-nd/2.5/ca/"],"dc:subject":["Temps de vol (Time-of-flight)","Diamètre","Stimulation","Volume sanguin cérébral","Flux sanguin cérébral","Time-of-flight","Diameter","Cerebral blood volume","Cerebral blood flow"],"dc:title":["Segmentation et extraction de caractéristiques des vaisseaux sanguins cérébraux à l'aide de l'IRM"],"dc:type":["Mémoire de maîtrise"],"thesis:degree_discipline":["Sciences des radiations et imagerie biomédicale"],"thesis:degree_level":["Maîtrise"],"thesis:degree_name":["M. Sc."],"thesis:institution_name":["Faculté de médecine et des sciences de la santé"]},"updated_at":"2026-07-27T21:07:45Z"}