ISMRM23 - Demystifying the fMRI Signal & Its Biophysical Origins III: Connecting the fMRI Signal to Other Modalities

ISMRM & ISMRT Annual Meeting & Exhibition • 03-08 June 2023 • Toronto, ON, Canada

Demystifying the fMRI Signal & Its Biophysical Origins III: Connecting the fMRI Signal to Other Modalities

Sunrise Course

ORGANIZERS: Natalia Petridou, Rita Schmidt

Wednesday, 07 June 2023

716A/B

07:00 - 08:00

Moderators: David Vaughan & Xin Yu

Skill Level: Basic to Intermediate

Session Number: S-W-08

CME Credit

Session Number: S-W-08

Overview
This is a sunrise educational course on the fMRI signal and its biophysical origins. The course will describe the fMRI biophysical signal origin and modeling, followed by analysis of the systematic and physiological components of the fMRI signal. In addition, the course will connect the fMRI signal to other modalities, including intra-cranial measurements and spectroscopy.

Target Audience
Scientists and clinicians interested in learning/refreshing their knowledge of the biophysical origins of the fMRI signal.

Educational Objectives
As a result of attending this course, participants should be able to:
- Describe the biophysical origins and biophysical models of the fMRI signal;
- Recognize the systematic and physiological noise contributions to the fMRI signal and review data acquisition methods to characterize the noise;
- Describe how the fMRI signal relates to intra-cranial measurements in animals and electrophysiological measurements in humans; and
- Explain relationships between the fMRI signal and underlying metabolic process, and review combined fMRI and spectroscopy data acquisition approaches.

07:00		fMRI vs. Intra-Cranial Measurements in Animals View Presentation Video Russell Chan Keywords: Contrast mechanisms: fMRI, Neuro: Brain function Understanding how individual cells and complex brain networks interact in both time and space is a grant challenge. Recent fMRI advancements provide opportunities to measure layer-specific cortical responses to potentially address key neuroscience questions. optogenetic fMRI (ofMRI) can map effects of controlling cell-type specific neuronal population. In this session, technical considerations in applying ofMRI and intra-cranial electrophysiological recordings will be examined. Subsequently, distinct local and brain-wide networks activated by optogenetic stimulation of neurons specific to different cortical layers will be reviewed, and layer-specific fMRI responses and their neuronal origins will be explored. Lastly, the opportunities and challenges will be discussed.
07:30		fMRI vs. Electrophysiology in Humans View Presentation Video Patricia Figueiredo Keywords: Contrast mechanisms: fMRI, Neuro: Brain function Because BOLD-fMRI probes neuronal activity indirectly and with a lag of a few seconds, based on neurovascular coupling mechanisms, several studies have attempted to clarify its neuronal correlates in humans by combining it with the simultaneous recording of the electroencephalogram (EEG). Like other electrophysiology techniques, EEG provides direct measures of neuronal activity with sub-millisecond temporal resolution, albeit poorer spatial resolution and coverage than BOLD-fMRI. In this talk, I will overview the main characteristics of electrophysiology relative to BOLD-fMRI as well as the evidence contributed by EEG-fMRI studies towards our understanding of the neuronal correlates of different types of BOLD-fMRI measurements.