Multi-Echo-Based Echo-Planar Spectroscopic Imaging Using a 3T MRI Scanner

The use of spin-echoes has been employed in an Echo-Planar Spectroscopic Imaging (EPSI) sequence to collect multiple phase encoded lines within a single TR in a Multi-Echo-based Echo-Planar Spectroscopic Imaging technique (MEEPSI). Despite the T2 dependence on the amplitude of the spin-echoes, the F...

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Bibliographic Details
Main Authors: Jon K. Furuyama, Brian L. Burns, Neil E. Wilson, M. Albert Thomas
Format: Article
Language:English
Published: MDPI AG 2011-10-01
Series:Materials
Subjects:
Online Access:http://www.mdpi.com/1996-1944/4/10/1818/
Description
Summary:The use of spin-echoes has been employed in an Echo-Planar Spectroscopic Imaging (EPSI) sequence to collect multiple phase encoded lines within a single TR in a Multi-Echo-based Echo-Planar Spectroscopic Imaging technique (MEEPSI). Despite the T2 dependence on the amplitude of the spin-echoes, the Full Width at Half Maximum (FWHM) of the derived multi-echo Point Spread Function (PSF) is shown to decrease, indicating an improved overall spatial resolution without requiring any additional scan time. The improved spatial resolution is demonstrated in the one-dimensional (1D) spatial profiles of the N-Acetyl Aspartate (NAA) singlet along the phase encode dimension in a gray matter phantom. Although the improved spatial resolution comes at the expense of spectral resolution, it is shown in vivo that peak broadening due to T2* decay is more significant than the loss of resolution from using spin-echoes and therefore does not affect the ability to quantify metabolites using the LCModel fitting algorithm.
ISSN:1996-1944