English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
 
 
DownloadE-Mail
  Accelerated 3D-EPI fMRI Using Parallel Imaging

Nguyen, T., Moeller, S., Goerke, U., & Ugurbil, K. (2006). Accelerated 3D-EPI fMRI Using Parallel Imaging. Poster presented at 23rd Annual Scientific Meeting of the ESMRMB 2006, Warsaw, Poland.

Item is

Basic

show hide
Item Permalink: http://hdl.handle.net/11858/00-001M-0000-0013-D05F-5 Version Permalink: http://hdl.handle.net/21.11116/0000-0004-B587-7
Genre: Poster

Files

show Files

Locators

show

Creators

show
hide
 Creators:
Nguyen, T1, 2, Author              
Moeller , S, Author
Goerke, U, Author
Ugurbil, K, Author
Affiliations:
1Former Department MRZ, Max Planck Institute for Biological Cybernetics, Max Planck Society, Spemannstrasse 38, 72076 Tübingen, DE, ou_2528700              
2Max Planck Institute for Biological Cybernetics, Max Planck Society, Spemannstrasse 38, 72076 Tübingen, DE, ou_1497794              

Content

show
hide
Free keywords: -
 Abstract: Introduction: Fast, three-dimensional acquisition is advantageous for fMRI1. While advanced 3D methods have been demonstrated for fMRI, 2Dmulti- slice EPI remains the convention. Extension to 3D-EPI using phaseencoding in the slice selection direction has presented feasible results2, but to our knowledge so far only within the conventional EPI temporal framework. Parallel imaging (PI) can provide a desirable improvement in both temporal resolution and CNR. This work seeks to evaluate some features of employing accelerated 3D-EPI for fMRI compared to conventional method. Methods: Data acquisition: 3T Siemens scanner, 8-channel head coil, segmented EPI sequence. Studies were performed on a healthy volunteer using four EPI schemes: conventional 2D-multi-slice, 3D full volume scan, 3D scans accelerated in 1-dimension with reduction factors R=2 and R=4. All acquisition parameters were identical except for variations inherent to the 2D sequence. Volumes of 20 slices were attained in ~7 s in 2D-multislice and down to ~2 s in 3D with R=4. Reconstruction was offline using GRAPPA. Functional imaging: motor task paradigm with self-paced, right-handed finger tapping ~30s off / 30s on blocks. Time series with 90 repetitions were acquired and activation maps (t-scores) were generated with variations in thresholds accounting for differences in intrinsic CNR and SNR (fig. 2). Results: Results show overall similar activation structure in the contralateral primary motor cortex and the supplementary motor area (fig. 1). Activation was detected consistently with all acquisition schemes (fig. 2), even with high 1-dimensional undersampling. The activation maps for R=4 showed a smaller reduction in t-scores (~30 ) compared to the reduction in SNR (75). Further, acceleration reduced total scan time up to a factor of 3.5 relative to the full k-space acquisitions. Conclusion: Acceleration offers significant gains to 3D-EPI for fMRI. Although loss of spatial SNR with shortened acquisition time is expected to reduce t-scores, acceleration is feasible due to the increase in acquired volumes per time and relatively disproportional smaller loss of CNR. Limits to acceleration are indicated in the activation maps as further reduction will give proportionally decreased CNR. However, high 1-dimensional reduction factors were shown to be feasible, achieving both spatial specificity of the functional response and higher temporal resolution than obtainable with 2Dmulti- slice within equal scan durations and spatial coverage. Additionally, a 3D scheme offers the possibility of two-dimensional acceleration for further imaging flexibility.

Details

show
hide
Language(s):
 Dates: 2006-09
 Publication Status: Published in print
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Method: -
 Identifiers: DOI: 10.1007/s10334-006-0043-1
BibTex Citekey: 5553
 Degree: -

Event

show
hide
Title: 23rd Annual Scientific Meeting of the ESMRMB 2006
Place of Event: Warsaw, Poland
Start-/End Date: 2006-09-21 - 2006-09-23

Legal Case

show

Project information

show

Source 1

show
hide
Title: Magnetic Resonance Materials in Physics, Biology and Medicine
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: Amsterdam : No longer published by Elsevier
Pages: - Volume / Issue: 19 (Supplement 1) Sequence Number: 622 Start / End Page: 306 - 307 Identifier: ISSN: 0968-5243
CoNE: https://pure.mpg.de/cone/journals/resource/954926245532