ABSTRACT
In a typical fMRI study, a measurement session includes (1) the acquisition of one or multiple time series of “functional” volumes while a subject performs
in a predefined sensory, motor, or cognitive stimulation paradigm and (2) the acquisition of an “anatomical” volume covering a certain region of interest (possibly the whole brain). Functional time series are acquired using fast or ultrafast MR sequences sensitive to blood oxygenation level dependent (BOLD) contrast (conventionally, T2/T2*-weighted echo planar imaging [EPI] sequences). Anatomical volumes, conversely, are acquired using slow MR sequences in which the contrast between gray and white matter is enhanced (conventionally, highspatial-resolution three-dimensional [3-D] T1-weighted sequences) and serve as a structural reference for the visualization of the functional information obtained through the analysis of the functional time series.
