A single-sided magnet for deep-depth fat quantification

• DOI: 10.1016/j.jmr.2021.107053
• Publication Date: 2021-08-13T22:52:29Z
• Authors: Ya Wang; Yajie Xu; Mingkang Zhang; Temitope Emmanuel...; Weiqian Wang; Hai Luo; Xiao Chen; Xiaodong Yang; Ziyue Wu
• Keywords: 03 medical and health sciences; Magnetic Resonance Spectroscopy; 0302 clinical medicine; Adipose Tissue; Liver; Phantoms, Imaging; Magnets; Magnetic Resonance Imaging

Early detection of fatty-liver disease is important before further aggravations of the disease, such as cirrhosis, can develop. In this study, we developed a low-cost, movable single-sided magnet for in vivo liver fat quantification. A gradient field of 73.5 G/cm and a field strength of 0.0725 T were obtained by structurally optimizing the concave U-shaped magnet, on which the region of interest (ROI) was a curved shape about 0.4 mm thick, 8 cm above the surface of the radiofrequency (RF) coil. We constructed a prototype nuclear magnetic-resonance (NMR) relaxometry system based on this optimized magnet. Subsequent phantom experiments demonstrated the effectiveness of the single-sided magnet in evaluating different proton density fat fraction (PDFF) phantoms. As expected, the results of the six phantoms showed good positive correlation between PDFF and the fitted fat amplitude, which suggested that single-sided NMR relaxometry could be used to quantify liver fat in vivo.