Definition: Bold oxygenation level dependent contrast refers to intravascular and extravascular relaxation time
(magnetic field inhomogeneity) and relaxation time
contrast changes that result from variations in the deoxyhemoglobin concentration of blood. The blood oxygenation level dependent contrast mechanism (
) is widely used for functional MRI because changes in neuronal activity level normally result in changes in oxyhemoglobin and deoxyhemoglobin concentration. Functional MRI is able to capture the changes only in deoxyhemoglobin concentration due to it being a paramagnetic material in blood. There is also a (substantially smaller) effect of overall blood volume in a voxel.
Category: Neuroscience
Related terms: Hemodynamic response function, (functional) magnetic resonance imaging
Abbreviation or symbol: BOLD
Synonym: Blood Oxygen Level Dependent Response (BOLD Response)
References: https://doi.org/10.1073%2Fpnas.87.24.9868b
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English