Variable-density spiral-in/out functional magnetic resonance imaging
Article first published online: 30 NOV 2010
Copyright © 2010 Wiley-Liss, Inc.
Magnetic Resonance in Medicine
Volume 65, Issue 5, pages 1287–1296, May 2011
How to Cite
Chang, C. and Glover, G. H. (2011), Variable-density spiral-in/out functional magnetic resonance imaging. Magn Reson Med, 65: 1287–1296. doi: 10.1002/mrm.22722
- Issue published online: 15 APR 2011
- Article first published online: 30 NOV 2010
- Manuscript Accepted: 17 OCT 2010
- Manuscript Revised: 12 OCT 2010
- Manuscript Received: 23 JUL 2010
- NIH. Grant Numbers: F31-AG032168, P41-RR009784
- variable-density spiral;
- high resolution
A variable-density spiral k-space trajectory is introduced for brain functional magnetic resonance imaging. The proposed spiral trajectory consists of an Archimedean spiral from the k-space origin to an arbitrary fraction r of the maximum k-space radius, extending beyond this point with a variable-density spiral in which the sampling density decreases as the k-space radius increases. It, therefore, permits a reduction in readout time at the expense of undersampling only the high spatial frequencies, in which the energy in T2*-weighted brain images is low. The trajectory was implemented in a two-dimensional spiral-in/out sequence, and single-shot high-resolution (1.72 × 1.72 mm2 in-plane) functional magnetic resonance imaging data were acquired from human volunteers. Compared with a two-shot fully Archimedean spiral sequence with the same spatial coverage and total scan time, the variable-density sequence yielded greater activation magnitudes with improved temporal efficiency and minor artifacts. Magn Reson Med, 2011. © 2010 Wiley-Liss, Inc.