title: Linear Response Equilibrium versus echo-planar encoding for fast high-spatial resolution 3D chemical shift imaging.
abstract: In this work Linear Response Equilibrium (LRE) and Echo-planar spectroscopic imaging (EPSI) are compared in terms of sensitivity per unit time and power deposition. In addition an extended dual repetition time scheme to generate broad stopbands for improved inherent water suppression in LRE is presented. The feasibility of LRE and EPSI for assessing cholesterol esters in human carotid plaques with high spatial resolution of 1.95×1.15×1.15 mm(3) on a clinical 3T MR system is demonstrated. In simulations and phantom experiments it is shown that LRE has comparable but lower sensitivity per unit time relative to EPSI despite stronger signal generated. This relates to the lower sampling efficiency in LRE relative to EPSI as a result of limited gradient performance on clinical MR systems. At the same time, power deposition of LRE is significantly reduced compared to EPSI making it an interesting niche application for in vivo high field spectroscopic imaging of metabolites within a limited bandwidth.
authors: Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, CH-8092 Zurich, Switzerland. fischer@biomed.ee.ethz.ch
authors: Rudolf Fritz
authors: RF
authors: Fischer
authors: Christof
authors: C
authors: Baltes
authors: Kilian
authors: K
authors: Weiss
authors: Aju
authors: A
authors: Pazhenkottil
authors: Markus
authors: M
authors: Rudin
authors: Peter
authors: P
authors: Boesiger
authors: Sebastian
authors: S
authors: Kozerke