Oxygenation-sensitive Mri
Oxygenation-sensitive Mri - Related Videos
08:35
Oxygenation-sensitive Cardiac MRI with Vasoactive Breathing Maneuvers for the Non-invasive Assessment of Coronary Microvascular Dysfunction
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Cited by 16 •
2022
The assessment of microvascular function by oxygenation-sensitive cardiac magnetic resonance imaging in combination with vasoactive breathing maneuvers is unique in its ability to assess rapid dynamic changes in myocardial oxygenation in vivo and, thus, may serve as a critically important diagnostic technique for coronary vascular function.
16:20
Hyperpolarized Xenon for NMR and MRI Applications
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Cited by 28 •
2012
The production of hyperpolarized xenon by means of spin exchange optical pumping (SEOP) is described. This method yields a ~10000-fold enhancement of the nuclear spin polarization of Xe-129 and has applications in nuclear magnetic resonance spectroscopy and imaging. Examples of gas phase and solution state experiments are given.
08:58
Cerebral Blood Oxygenation Measurement Based on Oxygen-dependent Quenching of Phosphorescence
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Cited by 28 •
2011
We present an experimental procedure for measuring the partial pressure of oxygen (pO2) in cerebral vasculature based on oxygen-dependent quenching of phosphorescence. Animal preparation and imaging procedures were outlined for both large field of view CCD-based imaging of pO2 in rats and 2-photon excitation based imaging of pO2 in mice.
06:06
Optogenetic Functional MRI
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Cited by 15 •
2016
This protocol describes the steps and data analysis required to successfully perform optogenetic functional magnetic resonance imaging (ofMRI). ofMRI is a novel technique that combines high-field fMRI readout with optogenetic stimulation, allowing for cell type-specific mapping of functional neural circuits and their dynamics across the whole living brain.
09:33
MRI Mapping of Cerebrovascular Reactivity via Gas Inhalation Challenges
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Cited by 79 •
2014
Non-invasive imaging of the brain vasculature’s ability to dilate or constrict may allow a better understanding of cerebrovascular pathophysiology in various neurological diseases. The present report describes a reproducible and patient-comfortable protocol to perform vascular reactivity imaging in humans using magnetic resonance imaging (MRI).
FAQs
Deoxygenated hemoglobin is paramagnetic, meaning it changes the local magnetic field around blood. This field disturbance influences nearby proton behavior and alters the T2*-weighted MRI signal. As the relative amounts of oxygenated and deoxygenated blood change, the measured signal changes as well, allowing imaging to track oxygenation-related vascular responses.
T2*-weighted imaging is sensitive to magnetic-field variations produced by deoxygenated hemoglobin. Consequently, signal changes reflect shifts in the balance between oxygenated and deoxygenated blood rather than simply displaying anatomy. This makes T2*-weighted contrast central to assessing oxygenation-related changes associated with vascular function, metabolism, and regional physiological activity.
A measurable shift can occur when the balance between oxygenated and deoxygenated blood changes within tissue. Those changes may accompany altered vascular function, tissue metabolism, or oxygen delivery. Interpreting the signal therefore connects MRI findings with physiological processes rather than treating the image as a direct measurement of oxygen concentration alone.
This approach commonly uses blood-oxygen-level-dependent contrast generated by the magnetic properties of endogenous hemoglobin, so an external contrast agent is not required. That distinction allows investigators to examine oxygenation-related changes through the tissue's own blood signal while studying vascular function, metabolism, and oxygen delivery in a noninvasive imaging framework.
Changes in blood oxygenation can provide information about brain activity because functional changes are associated with shifts in the balance of oxygenated and deoxygenated blood. In medical research, this makes the technique useful for functional brain studies, where regional signal variations help investigate activity-related vascular responses without relying on an external contrast agent.
Signal changes related to blood oxygenation can be used to examine how tissue responds when vascular function or oxygen delivery changes. This supports assessment of perfusion and vascular reactivity, which describe blood supply and the responsiveness of vessels. The resulting information can help characterize whether tissue oxygenation is being maintained appropriately.
Ischemia and tumor hypoxia both involve disrupted or inadequate oxygen delivery, making oxygenation-related imaging clinically relevant. The technique can help evaluate tissue conditions associated with ischemia, identify oxygen deprivation within tumors, and support assessment of treatment response. Its value comes from linking regional signal changes to vascular and metabolic abnormalities.