Noise analysis for 3‐point chemical shift‐based water‐fat separation with spectral modeling of fat |
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Authors: | Venkata V. Chebrolu MS Huanzhou Yu PhD Angel R. Pineda PhD Charles A. McKenzie PhD Jean H. Brittain PhD Scott B. Reeder MD PhD |
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Affiliation: | 1. Department of Biomedical Engineering, University of Wisconsin, Madison, Wisconsin, USA;2. Global MR Applied Science Laboratory, GE Healthcare, Menlo Park, California, USA;3. Department of Mathematics, California State University, Fullerton, California, USA;4. Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada;5. Global MR Applied Science Laboratory, GE Healthcare, Madison, Wisconsin, USA;6. Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA;7. Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, USA;8. Department of Medicine, University of Wisconsin, Madison, Wisconsin, USA |
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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 fat‐water 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. J. Magn. Reson. Imaging 2010;32:493–500. © 2010 Wiley‐Liss, Inc. |
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Keywords: | chemical shift imaging water‐fat separation IDEAL spectral modeling of fat Cramé r‐Rao bound |
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