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Functional magnetic resonance imaging

Functional magnetic resonance imaging
Researcher checking fMRI images Functional magnetic resonance imaging or functional MRI (fMRI) is a functional neuroimaging procedure using MRI technology that measures brain activity by detecting associated changes in blood flow.[1] This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area of the brain is in use, blood flow to that region also increases. The primary form of fMRI uses the Blood-oxygen-level dependent (BOLD) contrast,[2] discovered by Seiji Ogawa. The procedure is similar to MRI but uses the change in magnetization between oxygen-rich and oxygen-poor blood as its basic measure. FMRI is used both in the research world, and to a lesser extent, in the clinical world. Overview[edit] The fMRI concept builds on the earlier MRI scanning technology and the discovery of properties of oxygen-rich blood. History[edit] Three studies in 1992 were the first to explore using the BOLD contrast in humans. Physiology[edit] Related:  Medical

Diffusion MRI Diffusion MRI (or dMRI) is a magnetic resonance imaging (MRI) method which came into existence in the mid-1980s.[1][2][3] It allows the mapping of the diffusion process of molecules, mainly water, in biological tissues, in vivo and non-invasively. Molecular diffusion in tissues is not free, but reflects interactions with many obstacles, such as macromolecules, fibers, membranes, etc. Water molecule diffusion patterns can therefore reveal microscopic details about tissue architecture, either normal or in a diseased state. The first diffusion MRI images of the normal and diseased brain were made public in 1985.[4][5] Since then, diffusion MRI, also referred to as diffusion tensor imaging or DTI (see section below) has been extraordinarily successful. In diffusion weighted imaging (DWI), the intensity of each image element (voxel) reflects the best estimate of the rate of water diffusion at that location. Diffusion[edit] Given the concentration and flux where D is the diffusion coefficient.

Imagerie par résonance magnétique fonctionnelle Un article de Wikipédia, l'encyclopédie libre. L’imagerie par résonance magnétique fonctionnelle (IRMf) est une application de l'imagerie par résonance magnétique permettant de visualiser, de manière indirecte, l'activité cérébrale. Il s'agit d'une technique d'imagerie utilisée pour l'étude du fonctionnement du cerveau. Elle consiste à enregistrer des variations hémodynamiques (variation des propriétés du flux sanguin) cérébrales locales minimes, lorsque ces zones sont stimulées. Historique[modifier | modifier le code] Charles Roy et Charles Sherrington furent les premiers à faire le lien entre l'activité cérébrale et le flux sanguin, à l'université de Cambridge. Principe[modifier | modifier le code] Dans les zones activées par la tâche, une petite augmentation de la consommation d'oxygène par les neurones est surcompensée par une large augmentation de flux sanguin. Ainsi, in vivo, le milieu extravasculaire possède une faible susceptibilité magnétique, tout comme le sang oxygéné.

Diffusion MRI Diffusion MRI (or dMRI) is a magnetic resonance imaging (MRI) method which came into existence in the mid-1980s.[1][2][3] It allows the mapping of the diffusion process of molecules, mainly water, in biological tissues, in vivo and non-invasively. Molecular diffusion in tissues is not free, but reflects interactions with many obstacles, such as macromolecules, fibers, membranes, etc. Water molecule diffusion patterns can therefore reveal microscopic details about tissue architecture, either normal or in a diseased state. The first diffusion MRI images of the normal and diseased brain were made public in 1985.[4][5] Since then, diffusion MRI, also referred to as diffusion tensor imaging or DTI (see section below) has been extraordinarily successful. Its main clinical application has been in the study and treatment of neurological disorders, especially for the management of patients with acute stroke. Diffusion[edit] Given the concentration and flux where D is the diffusion coefficient. .

Electroencephalography Simultaneous video and EEG recording of two guitarists improvising. Electroencephalography (EEG) is the recording of electrical activity along the scalp. EEG measures voltage fluctuations resulting from ionic current flows within the neurons of the brain.[1] In clinical contexts, EEG refers to the recording of the brain's spontaneous electrical activity over a short period of time, usually 20–40 minutes, as recorded from multiple electrodes placed on the scalp. Diagnostic applications generally focus on the spectral content of EEG, that is, the type of neural oscillations that can be observed in EEG signals. EEG is most often used to diagnose epilepsy, which causes obvious abnormalities in EEG readings.[2] It is also used to diagnose sleep disorders, coma, encephalopathies, and brain death. History[edit] Hans Berger In 1934, Fisher and Lowenback first demonstrated epileptiform spikes. In 1947, The American EEG Society was founded and the first International EEG congress was held.

Magnetic resonance imaging Magnetic resonance imaging (MRI), nuclear magnetic resonance imaging (NMRI), or magnetic resonance tomography (MRT) is a medical imaging technique used in radiology to investigate the anatomy and function of the body in both health and disease. MRI scanners use strong magnetic fields and radiowaves to form images of the body. The technique is widely used in hospitals for medical diagnosis, staging of disease and for follow-up without exposure to ionizing radiation. Introduction[edit] Neuroimaging[edit] MRI image of white matter tracts. MRI is the investigative tool of choice for neurological cancers as it is more sensitive than CT for small tumors and offers better visualization of the posterior fossa. Cardiovascular[edit] MR angiogram in congenital heart disease Cardiac MRI is complementary to other imaging techniques, such as echocardiography, cardiac CT and nuclear medicine. Musculoskeletal[edit] Liver and gastrointestinal MRI[edit] Functional MRI[edit] Oncology[edit] How MRI works[edit]

Neuron All neurons are electrically excitable, maintaining voltage gradients across their membranes by means of metabolically driven ion pumps, which combine with ion channels embedded in the membrane to generate intracellular-versus-extracellular concentration differences of ions such as sodium, potassium, chloride, and calcium. Changes in the cross-membrane voltage can alter the function of voltage-dependent ion channels. If the voltage changes by a large enough amount, an all-or-none electrochemical pulse called an action potential is generated, which travels rapidly along the cell's axon, and activates synaptic connections with other cells when it arrives. Neurons do not undergo cell division. In most cases, neurons are generated by special types of stem cells. A type of glial cell, called astrocytes (named for being somewhat star-shaped), have also been observed to turn into neurons by virtue of the stem cell characteristic pluripotency. Overview[edit] Anatomy and histology[edit]

Conception et évaluation clinique d’un système d’aide au diagnostic (CAD) pour l’imagerie TEP/TDM du cancer | CREATIS Conception et évaluation clinique d’un système d’aide au diagnostic (CAD) pour l’imagerie pour l’imagerie IRM multi-séquences du cancer de la prostate Contexte: Le laboratoire CREATIS développe des systèmes d’aide au diagnostic (CAD en anglais pour ‘Computer Aided Diagnosis’) pour l’imagerie du cancer. Ces outils logiciels sont conçus pour aider les médecins dans leur diagnostic en fournissant une cartographie des zones suspectes de l’image. Le principe est d’extraire des caractéristiques de l'image puis d’élaborer un modèle de prédiction à partir d'une base de données d'apprentissage. Ce modèle empirique permet ensuite de quantifier la probabilité qu’une zone d’intérêt ou qu’un voxel d’une image test soit pathologique. Nous avons initié dans ce contexte une collaboration avec le professeur Rouvière, radiologue affilié à l’unité Inserm U1032 pour développer un système d’aide au diagnostic du cancer de la prostate basé sur la fusion d’images IRM multi-séquences. Compétences requises:

Brain Atlas - Introduction The central nervous system (CNS) consists of the brain and the spinal cord, immersed in the cerebrospinal fluid (CSF). Weighing about 3 pounds (1.4 kilograms), the brain consists of three main structures: the cerebrum, the cerebellum and the brainstem. Cerebrum - divided into two hemispheres (left and right), each consists of four lobes (frontal, parietal, occipital and temporal). – closely packed neuron cell bodies form the grey matter of the brain. Cerebellum – responsible for psychomotor function, the cerebellum co-ordinates sensory input from the inner ear and the muscles to provide accurate control of position and movement. Brainstem – found at the base of the brain, it forms the link between the cerebral cortex, white matter and the spinal cord. Other important areas in the brain include the basal ganglia, thalamus, hypothalamus, ventricles, limbic system, and the reticular activating system. Basal Ganglia Thalamus and Hypothalamus Ventricles Limbic System Reticular Activating System Glia

Magnetic resonance imaging Magnetic resonance imaging (MRI), nuclear magnetic resonance imaging (NMRI), or magnetic resonance tomography (MRT) is a medical imaging technique used in radiology to investigate the anatomy and function of the body in both health and disease. MRI scanners use strong magnetic fields and radiowaves to form images of the body. The technique is widely used in hospitals for medical diagnosis, staging of disease and for follow-up without exposure to ionizing radiation. Introduction[edit] Neuroimaging[edit] MRI image of white matter tracts. MRI is the investigative tool of choice for neurological cancers as it is more sensitive than CT for small tumors and offers better visualization of the posterior fossa. Cardiovascular[edit] MR angiogram in congenital heart disease Cardiac MRI is complementary to other imaging techniques, such as echocardiography, cardiac CT and nuclear medicine. Musculoskeletal[edit] Liver and gastrointestinal MRI[edit] Functional MRI[edit] Oncology[edit] How MRI works[edit]

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