Abstract

fMRI Acquisition

Douglas Noll
University of Michigan
Biomedical Engineering

Functional brain imaging using MRI (functional MRI or fMRI) has become a valuable tool
for studying function/structure relationships in the human brain in both normal and
clinical populations. This presentation will briefly describe the physiological changes
associated with brain activity, including changes in blood flow, volume, and oxygenation.
The latter of these is the most common approach for functional MRI and can be
observed through changes in the MRI transverse relaxation time. This is known as
Blood Oxygenation Level Dependent (BOLD) contrast. Change in cerebral blood flow
can also be observed, usually through techniques that rely on labeling of arterial water
and tracking the tissue wash-in and exchange of the labeled water. Contrast agents and
a variety of other techniques can be used to map changes in cerebral blood volume.
Finally, the general goals for optimization of fMRI acquisition and suppression of artifacts
will be presented along with a description of how these issues drive specific choices in
fMRI acquisition methods and parameters.