Presented in part at the 13th Annual Meeting of ISMRM, Miami Beach, FL, USA, 2005.
Improved echo volumar imaging (EVI) for functional MRI†
Article first published online: 6 NOV 2006
Copyright © 2006 Wiley-Liss, Inc.
Magnetic Resonance in Medicine
Volume 56, Issue 6, pages 1320–1327, December 2006
How to Cite
van der Zwaag, W., Francis, S. and Bowtell, R. (2006), Improved echo volumar imaging (EVI) for functional MRI. Magn Reson Med, 56: 1320–1327. doi: 10.1002/mrm.21080
- Issue published online: 16 NOV 2006
- Article first published online: 6 NOV 2006
- Manuscript Accepted: 11 AUG 2006
- Manuscript Revised: 26 JUN 2006
- Manuscript Received: 11 MAR 2006
- Medical Research Council. Grant Number: G9900259
- echo volumar imaging;
- single shot;
Echo volumar imaging (EVI) is a 3D modification of echo-planar imaging (EPI) that allows data from an entire volume to be acquired following a single RF excitation. EVI provides a high rate of volumar data acquisition, which is advantageous for functional MRI (fMRI). However, few studies to date have applied EVI to fMRI, since because of gradient hardware limitations EVI generally has to be used with long sampling times, resulting in high sensitivity to susceptibility-induced distortions. In this study we modified the EVI sequence to improve its suitability for fMRI. The sampling time is reduced by the use of a high gradient-switching frequency, a small number of echoes, and outer volume suppression (OVS); rewind gradients ameliorate Nyquist ghosting; and phase correction via a calibration scan reduces ghosting and distortion. It is shown that the modified EVI sequence allows fMRI data to be acquired with a temporal resolution of 167 ms. Magn Reson Med, 2006. © 2006 Wiley-Liss, Inc.