Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8160078 | Magnetic Resonance Imaging | 2012 | 7 Pages |
Abstract
Magnetic resonance spectroscopy (MRS) has long been considered the golden standard for non-invasive measurement of tissue fat content. With improved techniques for fat/water separation, imaging has become an alternative to MRS for fat quantification. Several imaging models have been proposed, but their performance relative to MRS at very low fat contents is yet not fully established. In this work, imaging and spectroscopy were compared at 1.5 T and 3 T in phantoms with 0-3% fat fraction (FF). We propose a multispectral model with individual a priori R2 relaxation rates for water and fat, and a common unknown R2â² relaxation. Magnitude and complex image reconstructions were also compared. Best accuracy was obtained with the imaging method at 1.5 T. At 3 T, the FFs were underestimated due to larger fat-water phase shifts. Agreement between measured and true FF was excellent for the imaging method at 1.5 T (imaging: FFmeas= 0.98 FFtrueâ 0.01%, spectroscopy: FFmeas= 0.77 FFtrue+ 0.08%), and fair at 3 T (imaging: FFmeas= 0.91 FFtrueâ 0.19%, spectroscopy: FFmeas= 0.79 FFtrue+ 0.02%). The imaging method was able to quantify FFs down to approx. 0.5%. We conclude that the suggested imaging model is capable of fat quantification with accuracy and precision similar to or better than spectroscopy and offers an improvement vs. a model with a common R2* relaxation only.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Sven MÃ¥nsson, Pernilla Peterson, Edvin Johansson,