title: In vivo proton magnetic resonance spectroscopy of liver metabolites in non-alcoholic fatty liver disease in rats: T2 relaxation times in methylene protons.
abstract: The aim of this study was to evaluate the transverse relaxation time of methylene resonance as compared to other lipid resonances. The examinations were performed using a 3.0 T scanner with a point-resolved spectroscopy (PRESS) sequence. Lipid relaxation time in a lipid phantom filled with canola oil was estimated with a repetition time (TR) of 6000ms and echo time (TE) of 40-550ms. For in vivo proton magnetic resonance spectroscopy ((1)H-MRS), eight male Sprague-Dawley rats were given free access to a normal-chow (NC) and another eight male Sprague-Dawley rats were given free access to a high-fat (HF) diet. Both groups drank water ad libitum. T2 measurements in the rats' livers were conducted at a fixed TR of 6000ms and TE of 40-220ms. Exponential curve fitting quality was calculated through the coefficients of determination (R(2)). Chemical analyses of the phantom and livers were not performed, but T2 decay curves were acquired. The T2 relaxation time of methylene resonance was estimated as follows: NC rats, 37.1±4.3ms; HF rats, 31.4±1.8ms (p<0.05). The extrapolated M0 values were higher in HF rats than in NC rats (p<0.005). This study of (1)H MRS led to sufficient spectral resolution and signal-to-noise ratio differences to characterize the T2 relaxation times of methylene resonance. (1)H MRS relaxation times may be useful for quantitative characterization of various liver diseases, including fatty liver disease.
authors.affiliation: Department of Biomedical Engineering, and Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, #505 Banpo-Dong, Seocho-Gu, Seoul 137-701, Republic of Korea.
authors.forename: Kyu-Ho
authors.initials: KH
authors.lastname: Song
authors.affiliation: Center for Magnetic Resonance Research, Korea Basic Science Institute, Chungbuk 363-883, Republic of Korea; Department of Bio-Analytical Science, Korea University of Science and Technology, Daejeon 305-333, Republic of Korea.
authors.forename: Hyeon-Man
authors.initials: HM
authors.lastname: Baek
authors.affiliation: Department of Biomedical Engineering, and Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, #505 Banpo-Dong, Seocho-Gu, Seoul 137-701, Republic of Korea.
authors.forename: Do-Wan
authors.initials: DW
authors.lastname: Lee
authors.affiliation: Department of Biomedical Engineering, and Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, #505 Banpo-Dong, Seocho-Gu, Seoul 137-701, Republic of Korea. Electronic address: bychoe@catholic.ac.kr.
authors.forename: Bo-Young
authors.initials: BY
authors.lastname: Choe
mesh_terms: D000818:Animals; D059305:Diet, High-Fat; D008055:Lipids / Q000032:analysis; D008099:Liver / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D008297:Male; D065626:Non-alcoholic Fatty Liver Disease / Q000378:metabolism / Q000473:pathology*; D011522:Protons; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D008055:Lipids; D011522:Protons
keywords: High-fat diet; Non-alcoholic fatty liver disease; Normal-chow diet; Proton magnetic resonance spectroscopy; T2 relaxation time