PURPOSE: To develop a fat-water imaging method that allows reliable separation of the two tissues, uses established robust reconstruction methods, and requires only one single-echo acquisition. THEORY AND METHODS: The proposed method uses spectrally selective dual-band excitation in combination with CAIPIRINHA to generate separate images of fat and water simultaneously. Spatially selective excitation without cross-contamination is made possible by the use of spatial-spectral pulses. Fat and water images can either be visualized separately, or the fat images can be corrected for chemical shift displacement and, in gradient echo imaging, for chemical shift-related phase discrepancy, and recombined with water images, generating fat-water images free of chemical shift effects. Gradient echo and turbo spin echo sequences were developed based on this Simultaneous Multiple Resonance Frequency imaging (SMURF) approach and their performance was assessed at 3Tesla in imaging of the knee, breasts, and abdomen. RESULTS: The proposed method generated well-separated fat and water images with minimal unaliasing artefacts or cross-excitation, evidenced by the near absence of water signal attributed to the fat image and vice versa. The separation achieved was similar to or better than that using separate acquisitions with water- and fat-saturation or Dixon methods. The recombined fat-water images provided similar image contrast to conventional images, but the chemical shift effects were eliminated. CONCLUSION: Simultaneous Multiple Resonance Frequency imaging is a robust fat-water imaging technique that offers a solution to imaging of body regions with significant amounts of fat.

Athinoula A Martinos Center for Biomedical Imaging Department of Radiology Massachusetts General Hospital Harvard Medical School Boston MA USA

Centre of Advanced Imaging University of Queensland Brisbane QLD Australia

Christian Doppler Laboratory for Clinical Molecular MR Imaging Vienna Austria

Department of Internal Medicine 3 Division of Endocrinology and Metabolism Medical University of Vienna Vienna Austria

Department of Neurology Medical University of Graz Graz Austria

High Field MR Centre Center for Medical Physics and Biomedical Engineering Medical University of Vienna Vienna Austria

High Field MR Centre Department of Biomedical Imaging and Image Guided Therapy Medical University of Vienna Vienna Austria

Institute of Scientific Instruments of the CAS Brno Czech Republic

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