Early Detection of Steatohepatitis in Fatty Rat Liver by Using MR Elastography
Early Detection of Steatohepatitis in Fatty Rat Liver by Using MR Elastography
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DOI：
10.1148/radiol.2523081817
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发表时间：
2009-10-01
期刊：
影响因子：
19.7
通讯作者：
Van Beers, Bernard E.
中科院分区：
文献类型：
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作者：
Salameh, Najat;Larrat, Benoit;Van Beers, Bernard E.
目的：探讨磁共振（MR）弹性成像在脂肪肝大鼠非酒精性脂肪性肝炎诊断中的潜在价值。材料与方法：本研究经地区伦理委员会批准。54只大鼠在被喂食标准饮食、缺乏胆碱的饮食长达8周以诱导脂肪性肝炎或2周的乳酸钠饮食以诱导脂肪变性后进行成像；或在四氯化碳注射后48小时成像，以模拟急性肝损伤。7.0 T时进行MR弹性成像以评估肝黏弹性参数。脂肪变性和纤维化用形态计量学和生化分析进行量化。采用α -平滑肌肌动蛋白的形态计量学分析来评估肌成纤维细胞的活化。实时逆转录聚合酶链反应评价转化生长因子β 1和前胶原1、3作为纤维形成标志物的表达。在组织学分析中对炎症进行评分。结果：脂肪性肝炎大鼠的平均弹性（2.24 kPa +/- 0.19[标准差]vs 1.82 kPa +/- 0.22）和平均黏度（0.86 kPa +/- 0.10 vs 0.59 kPa +/- 0.12）在2周后显著增加（P < 0.005），同时观察到脂肪变性、炎症、肌成纤维细胞活化和其他纤维形成标志物的增加。5周后才出现纤维化。脂肪变性大鼠黏度增加（0.77 kPa +/- 0.11, P < 0.005），弹性保持不变。急性肝损伤大鼠肝弹性（2.96 kPa +/- 0.63）和黏度（0.85 kPa +/- 0.22）增加（P < 0.005），肝纤维化和炎症发生，但未见明显纤维化和脂肪变性。在所有大鼠的多变量分析中，肝弹性仅与肌成纤维细胞活化相关（P < 0.001, r < 0.6）。结论：结果表明，在非酒精性脂肪大鼠肝脏中，MR弹性成像可能有助于脂肪性肝炎的早期检测，因为它显示弹性增加并出现在纤维化发展之前，这与肌成纤维细胞活化有关。(c) rsna， 2009年
Purpose: To assess the potential value of magnetic resonance (MR) elastographic imaging to help detect nonalcoholic steatohepatitis in the fatty rat liver.Materials and Methods: This study was approved by the regional ethics committee. Fifty-four rats were imaged after being fed either a standard diet, a choline-deficient diet for up to 8 weeks to induce steatohepatitis, or a 2-week orotic acid diet to induce steatosis; or were imaged 48 hours after carbon tetrachloride injection to model acute liver injury. MR elastography was performed at 7.0 T to assess viscoelastic liver parameters. Steatosis and fibrosis were quantified with morphometric and biochemical analysis. Myofibroblast activation was assessed with morphometric analysis of alpha-smooth muscle actin. Expression of transforming growth factor beta 1 and procollagens 1 and 3 as markers of fibrogenesis was evaluated with real-time reverse transcription polymerase chain reaction. Inflammation was scored at histologic analysis.Results: In rats with steatohepatitis, mean elasticity (2.24 kPa +/- 0.19 [ standard deviation] vs 1.82 kPa +/- 0.22) and mean viscosity (0.86 kPa +/- 0.10 vs 0.59 kPa +/- 0.12) increased significantly (P < .005) after the 2-week orotic acid diet, while steatosis, inflammation, myofibroblast activation, and increase of other fibrogenesis markers were observed. Fibrosis appeared only after 5 weeks. In rats with steatosis, viscosity increased (0.77 kPa +/- 0.11, P < .005), elasticity remained constant. In rats with acute liver injury, elasticity (2.96 kPa +/- 0.63) and viscosity (0.85 kPa +/- 0.22) increased ( P < .005), while fibrogenesis and inflammation were observed without substantial fibrosis or steatosis. At multivariate analysis in all rats, liver elasticity correlated only with myofibroblast activation (P < .001, r > 0.6).Conclusion: The results suggest that in nonalcoholic fatty rat liver, MR elastography may be useful in the early detection of steatohepatitis by showing increased elasticity and appearing before fibrosis development, which was linked to myofibroblast activation. (C) RSNA, 2009