Paediatrics Publications
Document Type
Article
Publication Date
8-1-2010
Journal
Journal of Magnetic Resonance Imaging
Volume
32
Issue
2
First Page
493
Last Page
500
URL with Digital Object Identifier
10.1002/jmri.22220
Abstract
Purpose: To model the theoretical signal-to-noise ratio (SNR) behavior of 3-point chemical shift-based water-fat separation, using spectral modeling of fat, with experimental validation for spin-echo and gradient-echo imaging. The echo combination that achieves the best SNR performance for a given spectral model of fat was also investigated. Materials and Methods: Cramér-Rao bound analysis was used to calculate the best possible SNR performance for a given echo combination. Experimental validation in a fatwater phantom was performed and compared with theory. In vivo scans were performed to compare fat separation with and with out spectral modeling of fat. Results: Theoretical SNR calculations for methods that include spectral modeling of fat agree closely with experimental SNR measurements. Spectral modeling of fat more accurately separates fat and water signals, with only a slight decrease in the SNR performance of the water-only image, although with a relatively large decrease in the fat SNR performance. Conclusion: The optimal echo combination that provides the best SNR performance for water using spectral modeling of fat is very similar to previous optimizations that modeled fat as a single peak. Therefore, the optimal echo spacing commonly used for single fat peak models is adequate for most applications that use spectral modeling of fat. © 2010 Wiley-Liss, Inc.