A two-point Dixon technique for water-fat separation using multiresolution and region-growing algorithm / 南方医科大学学报

<p><b>OBJECTIVE</b>An improved water-fat separation method based on region-growing was proposed for use in regions with low signal-noise ratio (SNR).</p><p><b>METHODS</b>Region-growing method was applied to 4 sub-images acquired by a down- sampling operation on the acquired phasor maps. The spatial smoothing constraint was exploited to calculate 4 error phasor maps to construct the final smooth error phasor map, which was used in two-point Dixon technique for water-fat separation.</p><p><b>RESULTS</b>The simulation experiment showed that the proposed method produced smaller errors, and for clinical images of the knees, abdomen and lower limbs, the proposed method achieved accurate water-fat separations.</p><p><b>CONCLUSION</b>The proposed method is more robust and reliable than the original global region-growing algorithm, and serves as a promising water-fat separation method for clinical applications.</p>

The labeling of 3T3-L1 preadipocyte cells with enhanced green fluorescent protein / 生物工程学报

A cell model is desired for adipocyte differentiation investigation and for high-throughput screening of anti-obesity and anti-diabetes molecules from chemical resources due to the world wide epidemic of obesity and diabetes. In order to establish such a cell model, a plasmid of pPPARgamma2-promoter-EGFP was constructed by inserting a 660bp sequence of mouse PPARgamma2 promoter into the Ase I and Kpn I sites of pEGFP-N3 and transferred into 3T3-L1 preadipocyte cells. The cells were induced to differentiate and the expression of PPARgamma2 was detected by the microscopic observation of EGFP and by RT-PCR assays. The results showed that the EGFP gene expression patterns were similar to that of pPPARgamma2's, which indicated that the EGFP gene was transferred into the mouse 3T3-L1 preadipocyte cells, and its expression was under the control of pPPARgamma2 promoter. RT-PCR assays showed that the EGFP expression authentically represented the stable expression of PPARgamma2. In conclusion, a preadipocyte cell line expressing EGFP under the control of the promoter of adipocyte-specific expression gene PPARgamma2 was generated. The cell line provides a powerful approach for the research of adipocyte differentiation and for the high-throughput screening of anti-obesity and anti-diabetes chemicals.