SU‐F‐I‐65: Fatty Acid Quantification in High‐Fat‐Diet Induced Abnormal Intrahepatic Triglyceride Storage Using Internal Standard Method at 3.0 T

Abstract

Purpose:The objective of this study was to determine the metabolic changes in a rat model of high‐fat‐diet‐induced non‐alcoholic fatty liver disease (NAFLD) by using single‐voxel 1H‐MRS with a 3.0 T MRI scanner.Methods:The examination were performed on a 3.0T scanner using a 4‐channel animal coil for higher resolution. This method used point‐resolved spectroscopy (PRESS) (repetition time (TR)/echo time (TE) = 6000/35 ms; number of signal averages (NSA) = 64). To measure the lipid content, we quantified total lipids ((‐CH2‐)n/noise), total saturated fatty acids (3(‐CH2‐)/2(‐CH3)), total unsaturated fatty acids (3(‐CH2‐C=C‐CH2‐)/4(‐CH3)), total unsaturated bonds index (3(‐CH=CH‐)/2(‐CH3)), and polyunsaturated bonds index (3(=C‐CH2‐C=)/2(‐CH3)) by separating each peak area of (CH2)n, CH2C=CCH, =CCH2C=, and CH=CH by CH3. The ‐CH3 (0.90 ppm) peak was used as an internal chemical shift reference.Results:Total lipids and total saturated fatty acids were substantially upregulated in high‐fat‐diet‐fed rats in comparison with baseline values (total lipids, 16.22±6.60×10−4; total saturated fatty acids, 10.26±1.91). The resulting data on lipid accumulation were statistically significant in terms of total lipids at 3 weeks (78.65±36.20, p = 0.002), 6 weeks (88.14±22.36, p < 0.001), 9 weeks (78.55±31.29, P < 0.001), and 15 weeks (107.87±39.95, p < 0.001) after initiation of the high‐fat diet.Conclusion:Our results of noninvasive in vivo MRS are based on accurate monitoring of the changes in lipid content, which were verified using the data on saturated fatty acids and unsaturated fatty acids. We can conclude that localized MRS holds promise as an indicator of fatty liver diseases in humans and in animal models for monitoring treatment.