Tanpowpong Natthaporn, Panichyawat Sineenart
Diagnostic Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
J Ultrason. 2020 Nov;20(82):e169-e175. doi: 10.15557/JoU.2020.0028. Epub 2020 Sep 28.
Conventional ultrasonography can provide only semi-quantitative assessment of hepatic steatosis. The aim of this study was to assess sonographic hepatorenal ratio to quantify the severity of fatty liver. We performed a retrospective analysis of 179 patients with various liver diseases who underwent abdominal magnetic resonance imaging and ultrasonography on the same day. The hepatorenal ratio was calculated by the ratio between the mean echo intensity in regions of interests of the liver and regions of interests of the right renal cortex. Magnetic resonance imaging-proton density fat fraction was used as standard reference for steatosis grading. The effect of fibrosis measured by magnetic resonance elastography on the degree of correlation was also assessed. The hepatorenal ratio was highly correlated with magnetic resonance imaging-proton density fat fraction (Spearman's coefficient = 0.83) ( <0.001). High correlation of hepatorenal ratio with magnetic resonance imaging-proton density fat fraction was observed in patients with less than stage 2 fibrosis ( <0.001), whereas moderate correlation of hepatorenal ratio with magnetic resonance imaging-proton density fat fraction was found in patients with ≥ stage 2 fibrosis or higher ( <0.001). The hepatorenal ratio cutoff point for prediction of grade 1 hepatic steatosis was 1.18 with sensitivity of 90.0% and specificity of 80.0%. The hepatorenal ratio cutoff point for prediction of grade 2 and grade 3 hepatic steatosis was 1.55 and 1.60, respectively, with sensitivity greater than 90% and specificity greater than 80%. The hepatorenal ratio could become an effective quantitative tool for hepatic steatosis alternative to magnetic resonance imaging-proton density fat fraction. Application should be careful in the group of patients with stage 2 liver fibrosis or higher.
传统超声检查仅能对肝脂肪变性进行半定量评估。本研究旨在评估超声肝肾比以量化脂肪肝的严重程度。我们对179例患有各种肝脏疾病且在同一天接受腹部磁共振成像和超声检查的患者进行了回顾性分析。肝肾比通过肝脏感兴趣区域与右肾皮质感兴趣区域的平均回声强度之比来计算。磁共振成像 - 质子密度脂肪分数用作脂肪变性分级的标准参考。还评估了通过磁共振弹性成像测量的纤维化对相关程度的影响。肝肾比与磁共振成像 - 质子密度脂肪分数高度相关（斯皮尔曼系数 = 0.83）（<0.001）。在纤维化程度小于2期的患者中观察到肝肾比与磁共振成像 - 质子密度脂肪分数高度相关（<0.001），而在纤维化程度≥2期或更高的患者中发现肝肾比与磁共振成像 - 质子密度脂肪分数中度相关（<0.001）。预测1级肝脂肪变性的肝肾比临界值为1.18，敏感性为90.0%，特异性为80.0%。预测2级和3级肝脂肪变性的肝肾比临界值分别为1.55和1.60，敏感性大于90%，特异性大于80%。肝肾比可成为替代磁共振成像 - 质子密度脂肪分数的肝脂肪变性有效定量工具。对于2期或更高纤维化程度的患者组应谨慎应用。
