Abstract #0536

Investigating timing of BOLD fMRI responses in individual cortical vessels to short and long stimulus durations

Divya Varadarajan^1,2, Sebastien Proulx^1,2, Paul Wighton^1,2, Zhangxuan Hu^1,2, Jingyuan E Chen^1,2, Saskia Bollmann³, Avery J. L. Berman⁴, and Jonathan R. Polimeni^1,2,5

¹Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital,, Charlestown, MA, United States, ²Radiology, Harvard Medical School, Boston, MA, United States, ³The University of Queensland, St Lucia, Australia, ⁴Physics, Carleton University, Ottawa, ON, Canada, ⁵Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology,, Cambridge, MA, United States

Synopsis

Keywords: fMRI Acquisition, fMRI, Vessels, Vascular, Gray Matter, Oxygenation, fMRI (task based), fMRI Acquisition, fMRI Analysis, Hemodynamics

Motivation: Typical fMRI data observes hemodynamics from multiple vascular compartments in each voxel, however understanding the link between neuronal and vascular dynamics will require vessel-specific measurements.

Goal(s): To investigate the timing and amplitude of hemodynamic responses within individual arteries and veins of the human cortex and assess how they change with stimulus duration.

Approach: We applied single-vessel fMRI with multiple echoes to separate inflow and BOLD components, and distinguished intravascular and extravascular dynamics in and around arteries and veins.

Results: We observed faster dynamics in arteries, and a post-stimulus undershoot in all vessels, potentially providing new insights into hemodynamics in the human brain

Impact: Knowledge about hemodynamics within individual vascular compartment is provided by invasive microscopy in small-animal models, and less is known about hemodynamics in humans. Here we present vessel-specific measurements of hemodynamics in humans and reveal unexpected features in the fMRI response.

How to access this content:

For one year after publication, abstracts and videos are only open to registrants of this annual meeting. Registrants should use their existing login information. Non-registrant access can be purchased via the ISMRM E-Library.

After one year, current ISMRM & ISMRT members get free access to both the abstracts and videos. Non-members and non-registrants must purchase access via the ISMRM E-Library.

After two years, the meeting proceedings (abstracts) are opened to the public and require no login information. Videos remain behind password for access by members, registrants and E-Library customers.

Click here for more information on becoming a member.