Ian Shih, Ph.D., Associate Professor, University of North Carolina at Chapel Hill, A Silent, Sensitive, Specific, and Artifact-resisting fMRI Technique

Speaker:

Ian Shih, Ph.D.
Associate Professor of Neurology - Neuroscience Research
Associate Director, Biomedical Research Imaging Center
Director, Center for Animal MRI
University of North Carolina at Chapel Hill

Faculty Host
Arnab Mukherjee

A Silent, Sensitive, Specific, and Artifact-resisting fMRI Technique

Abstract:

Gradient-recalled echo (GRE)–based echo planar imaging (EPI) has been the gold standard functional magnetic resonance imaging (fMRI) technique for nearly three decades due to its ability to rapidly acquire whole brain volumes with MR T2* sensitivity to blood oxygenation — a well-known surrogate marker for brain activity. This immensely utilized technique, however, suffers from high acoustic noise, ghosting and motion artifacts, magnetic field inhomogeneity–related artifacts, low sensitivity compared to other neuroimaging modalities, and poor spatial specificity. An fMRI sampling technique that addresses these problems has the potential to change fMRI practices. Aptly, imaging sequences with “zero” acquisition delay and minimal increment of gradients are insensitive to problems stated above and have the potential to provide superior spatial specificity and sensitivity compared to GRE-EPI-fMRI. To explore the utility of a hard-pulse-based zero-echo-time (ZTE) sequence for fMRI, we modeled ZTE contrast mechanisms, improved its sequence design for fMRI, and examined parameters that may augment ZTE-fMRI sensitivity. We hope the results brought by these efforts to make positive influences on fMRI methods for broad neuroscience applications.

Bio: