Physiological MRI

Welcome to this special issue of the Open Neuroimaging Journal which focuses on physiological MRI as reviewed by a panel of leaders in the field. The use of MRI to investigate brain physiology has grown at a very rapid pace. The spatial resolution and spatial specificity of neuronal activiation as detected by fMRI have markedly improved over the past decade. The fMRI signal sources and the hemodynamic response functions are considerably better understood. Multimodal MRI techniques that include quantitative BOLD, blood flow, blood volume, and oxygen extraction fraction measurements are becoming routine. These techniques have been applied to study cerebral physiology and neuroenergetics under various experimental conditions in normal brains as well as diseased states such as stroke. Spontaneous low-frequency fluctuations of the BOLD fMRI signals also reveal the very dynamic brain at rest. The physiological data from multimodal MRI measurements are very rich in content and much work remains in order to completely decipher the information in these data.