Published online before print March 18, 2008, 10.1148/radiol.2472070880
(Radiology 2008;247:550.)
A more recent version of this article appeared on May 1, 2008
© RSNA, 2008
Liver Fat Content and T2*: Simultaneous Measurement by Using Breath-hold Multiecho MR Imaging at 3.0 T—Feasibility1
Declan P. O'Regan, MRCP, FRCR,
Martina F. Callaghan, PhD,
Marzena Wylezinska-Arridge, PhD,
Julie Fitzpatrick, DCR(R),
Rossi P. Naoumova, MD, PhD,
Joseph V. Hajnal, PhD, and
Stephan A. Schmitz, MD, PhD
1 From the Imaging Sciences Department and Clinical Research Facility, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, United Kingdom. Received May 18, 2007; revision requested July 19; revision received August 3; accepted September 7; final version accepted September 28. Supported by grants from Bayer Schering Pharma and Philips Medical Systems.
Address correspondence to D.P.O. (e-mail: declan.oregan@imperial.ac.uk).
Research ethics committee approval was obtained for this study, and written informed consent was obtained from all participants. The purpose was to prospectively evaluate the feasibility of breath-hold multiecho in- and out-of-phase magnetic resonance (MR) imaging for simultaneous lipid quantification and T2* measurement. A spoiled gradient-echo sequence with seven echo times alternately in phase and out of phase was used at 3.0 T. Imaging was performed in a lipid phantom, in five healthy volunteers (all men; mean age, 37 years), and in five obese individuals with hyperlipidemia or diabetes (four men, one woman; mean age, 53 years). A biexponential curve-fitting model was used to derive the relative signal contributions from fat and water, and these results were compared with results of liver proton MR spectroscopy, the reference standard. There was a significant correlation between multiecho and spectroscopic measurements of hepatic lipid concentration (r2 = 0.99, P < .001). In vivo, the T2* of water was consistently longer than that of fat and reliably enabled the signal components to be correctly assigned. In the lipid phantom, the multiecho method could be used to determine the fat-to-water ratio and the T2* values of fat and water throughout the entire range of fat concentrations. Multiecho imaging shows promise as a method of simultaneous fat and T2* quantification.
© RSNA, 2008
Copyright © 2008 by the Radiological Society of North America.