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 healthy and clinical populations. This presentation briefly describes the physiological changes associated with brain activity, including changes in blood flow, blood volume, and oxygenation.
Changes in blood oxygenation form the basis of the most common fMRI approach and can be detected through variations in the MRI transverse relaxation time. This mechanism is known as Blood Oxygenation Level Dependent (BOLD) contrast. Changes in cerebral blood flow can also be measured, typically using techniques that label arterial water and track its wash-in and exchange within tissue. In addition, contrast agents and other techniques can be employed to map changes in cerebral blood volume.
Finally, the general goals of optimizing fMRI acquisition and minimizing artifacts are discussed, along with an explanation of how these considerations influence the selection of specific acquisition methods and imaging parameters.
Presentation Files (Zip Archive)