Neuroscience 2003 Abstract
| Presentation Number: | 69.8 |
|---|---|
| Abstract Title: | Comparison of lateral point spread function of BOLD and CBF based functional MRI in cat visual cortex. |
| Authors: |
Park, J.*1
; Ronen, I.1
; Toth, L. J.2
; Ugurbil, K.1
; Kim, D.1
1Radiology, Ctr. for magnetic resonace Res., Minneapolis, MN 2MA, 2021 6th ST SE, 55455, |
| Primary Theme and Topics |
Sensory Systems - Vision -- Visual cortex: Functional organization and circuitry |
| Session: |
69. Imaging Visual Cortex Poster |
| Presentation Time: | Saturday, November 8, 2003 4:00 PM-5:00 PM |
| Location: | Morial Convention Center - Hall F-I, Board # H22 |
| Keywords: | Non-invasive method, Ultra-high magnetic field, Activation map, Upper and lower visual fields |
fMRI based on gradient echo (GE) BOLD effect is the most widely used method for studying brain function non-invasively in vivo. It is not clear, however, whether the spatial specificity of GE-BOLD fMRI could provide a viable tool for the investigation of cortical micro-organization, and whether alternative fMRI modalities such as CBF fMRI could be more suitable than GE-BOLD fMRI for this goal. To address this question, we investigated the lateral point spread function (PSF) in the cat visual cortex (area 18) with GE-BOLD and CBF fMRI on the same cats. All experiments were performed at ultra-high magnetic field, 9.4 T.
Four anesthetized cats (1.45 ~ 1.95 kg) were monocularly stimulated with sinusoidal wave gratings (0.15 cyc/deg, 2 Hz). Contiguous areas of the upper- and lower visual fields were alternately stimulated. The activation maps of GE-BOLD and CBF were analyzed, and the border between the areas activated by the stimulation of the upper and the lower visual fields was detected. Lateral PSFs of GE-BOLD and CBF were obtained by averaging pixel rows perpendicular to the border. The PSFs of GE-BOLD and CBF fMRI were 1.8 mm and 0.7 mm, respectively. It is postulated that the increase in specificity of the CBF-based fMRI modality is partly due to the suppression of the contribution of draining vessels, and that the major contribution to the CBF contrast originates from perfusion in the capillary bed. Spin-echo (SE) BOLD responses, also to be studied are expected to have a similar PSF as the CBF. These results suggest that the CBF technique is better suited for high-resolution investigation of cortical organization in brain, since it is more spatially localized relative to the BOLD fMRI.
Four anesthetized cats (1.45 ~ 1.95 kg) were monocularly stimulated with sinusoidal wave gratings (0.15 cyc/deg, 2 Hz). Contiguous areas of the upper- and lower visual fields were alternately stimulated. The activation maps of GE-BOLD and CBF were analyzed, and the border between the areas activated by the stimulation of the upper and the lower visual fields was detected. Lateral PSFs of GE-BOLD and CBF were obtained by averaging pixel rows perpendicular to the border. The PSFs of GE-BOLD and CBF fMRI were 1.8 mm and 0.7 mm, respectively. It is postulated that the increase in specificity of the CBF-based fMRI modality is partly due to the suppression of the contribution of draining vessels, and that the major contribution to the CBF contrast originates from perfusion in the capillary bed. Spin-echo (SE) BOLD responses, also to be studied are expected to have a similar PSF as the CBF. These results suggest that the CBF technique is better suited for high-resolution investigation of cortical organization in brain, since it is more spatially localized relative to the BOLD fMRI.
Supported by NIH (RR08079), The Keck Foundation, The MIND institute, and The Whitaker Foundation.
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2003 Neuroscience Meeting Planner. New Orleans, LA: Society for Neuroscience, 2003. Online.
Copyright © 2003-2026 Society for Neuroscience; all rights reserved. Permission to republish any abstract or part of any abstract in any form must be obtained in writing by SfN office prior to publication.
