Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
Acad Radiol. 2011 Mar;18(3):377-83. doi: 10.1016/j.acra.2010.10.012. Epub 2010 Dec 17.
The aim of this study was to characterize early hepatic lipid changes in an experimental model of liver fibrosis using proton ((1)H) magnetic resonance spectroscopy (MRS) at high magnetic field in vivo.
Liver fibrosis was induced in 12 Sprague-Dawley rats by twice-weekly carbon tetrachloride (CCl(4)) administration up to 4 weeks. Eight normal rats were used as controls. Single-voxel (1)H MRS experiments were performed at 7 Tesla to measure signal integrals of various lipid peaks including -CH(3), (-CH(2)-)(n), -CH(2)-C=C-CH(2)-, =C-CH(2)-C= and -CH=CH- at 0.9, 1.3, 2.0, 2.8, and 5.3 ppm, respectively, and peak from choline-containing compounds (CCC) at 3.2 ppm. Total lipid, total saturated fatty acid, total unsaturated fatty acid, total unsaturated bond, polyunsaturated bond, and CCC indices were quantified.
Significant increases (P < .01) in total lipid and total saturated fatty acid indices were found in animals with CCl(4)-induced fibrosis as compared with normal animals. In addition, total unsaturated bond and polyunsaturated bond indices of animals at 4 weeks after CCl(4) insult were significantly higher than (P < .01 and P < .05, respectively) those of normal animals and animals at 2 weeks following insult; whereas there was only significant increase (P < .01) in total unsaturated fatty acid index in animals with 4-week CCl(4) insult as compared with normal animals.
The hepatic lipid changes in CCl(4)-induced experimental fibrosis model were documented in vivo and longitudinally using (1)H MRS at 7 Tesla. The experimental findings suggested that total saturated fatty acid increase contributed mainly to the total lipid increase in animals with CCl(4) insult. This study also demonstrated the potential value of high field MRS to resolve lipid composition and alterations in liver fibrosis.
本研究旨在利用高场体内质子（1H）磁共振波谱（MRS）对肝纤维化实验模型中早期肝脏脂质变化进行特征描述。
通过每周两次给予四氯化碳（CCl4），12 只 Sprague-Dawley 大鼠被诱导至 4 周发生肝纤维化。8 只正常大鼠作为对照组。在 7T 下进行单体素（1）H MRS 实验，以测量各种脂质峰的信号积分，包括-CH3、-（CH2）-（n）、-CH2-C=C-CH2-、=C-CH2-C=和-CH=CH-，分别位于 0.9、1.3、2.0、2.8 和 5.3ppm，以及位于 3.2ppm 的胆碱化合物（CCC）峰。定量总脂质、总饱和脂肪酸、总不饱和脂肪酸、总不饱和键、多不饱和键和 CCC 指数。
与正常动物相比，CCl4 诱导纤维化的动物中总脂质和总饱和脂肪酸指数显著增加（P <.01）。此外，CCl4 损伤后 4 周动物的总不饱和键和多不饱和键指数明显高于（P <.01 和 P <.05，分别）正常动物和损伤后 2 周动物，而仅在 4 周 CCl4 损伤的动物中观察到总不饱和脂肪酸指数显著增加（P <.01）与正常动物相比。
在 7T 下使用 1H MRS 对 CCl4 诱导的实验性肝纤维化模型中的肝脂质变化进行了体内和纵向记录。实验结果表明，在 CCl4 损伤的动物中，总饱和脂肪酸的增加主要导致总脂质增加。本研究还证明了高场 MRS 解析肝纤维化中脂质组成和变化的潜在价值。
