Contrast-enhanced ultrasonography for the evaluation of liver fibrosis after biliary obstruction

AIM:To investigate perfusion change in contrastenhanced ultrasonography(CEUS) to evaluate liver fibrosis based on biliary obstruction using an animal model.METHODS:New Zealand white rabbits(3-4 kg) underwent bile duct ligation to form a biliary obstruction model.We performed liver CEUS and laboratory tests on the day before the operation(day 0) and every 7 postoperative days until the rabbits were sacrificed.After CEUS,signal intensity of liver parenchyma with a time-intensity curve was analyzed.Perfusion parameters were automatically calculated from regionof-interests,including peak signal intensity,mean transit time,area under the curve and time to peak.Histological grades of liver fibrosis were assessed according to the Metavir score system immediately after sacrifice.Generalized estimating equations were used to analyze the association between liver fibrosis grades and perfusion parameters for statistical analysis.The perfusion parameters were measured on the last day and the difference between day 0 and the last day were evaluated.RESULTS:From the nine rabbits,histological grades of liver fibrosis were grade 1 in one rabbit,grade 2 and 3 in three rabbits each,and grade 4 in two rabbits.Among the four CEUS parameters,only the peak signal intensity measured on the last day demonstrated a significant association with liver fibrosis grades(OR =1.392,95%CI:1.114-1.741,P =0.004).The difference in peak signal intensity between day 0 and the last dayalso demonstrated an association with liver fibrosis(OR =1.191,95%CI:0.999-1.419,P =0.051).The other parameters tested,including mean transit time,area under the curve,and time to peak,showed no significant correlation with liver fibrosis grades.CONCLUSION:This animal study demonstrates that CEUS can be used to evaluate liver fibrosis from biliary obstruction using peak signal intensity as a parameter.

新生儿和婴儿胆道闭锁的彩色多普勒超声表现

目的描述胆道闭锁（BA）新生儿的肝脏彩色多普勒超声（US）表现．并同无BA的新生儿和正常对照组新生儿的肝脏US进行对照。材料与方法本研究经学术审核委员会的批准．可免除知情同意。回顾性分析64例胆汁淤积新生儿和19例正常对照新生儿的US和彩色多普勒US表现。BA与非BA确诊者分别为29例和35例。3名小儿放射科医生对US和彩色多普勒US表现进行评价，独立记录影像表现，有差异时协商取得一致意见。

Hepatic fat quantification magnetic resonance for monitoring treatment response in pediatric nonalcoholic steatohepatitis

AIM: To evaluate the possibility of treatment effect monitoring using hepatic fat quantification magnetic resonance(MR) in pediatric nonalcoholic steatohepatitis(NASH).METHODS: We retrospectively reviewed the medical records of patients who received educational recommendations and vitamin E for NASH and underwent hepatic fat quantification MR from 2011 to 2013.Hepatic fat fraction(%) was measured using dual- and triple-echo gradient-recalled-echo sequences at 3T.The compliant and non-compliant groups were compared clinically,biochemically,and radiologically.RESULTS: Twenty seven patients(M:F = 24:3; mean age: 12 ± 2.3 years) were included(compliant group = 22,non-compliant = 5).None of the baseline findings differed between the 2 groups,except for triglyceride level(compliant vs non-compliant,167.7 mg/d L vs 74.2 mg/d L,P = 0.001).In the compliant group,high-density lipoprotein increased and all other parameters decreased after 1-year follow-up.However,there were various changes in the non-compliant group.Dualecho fat fraction(-19.2% vs 4.6,P < 0.001),tripleecho fat fraction(-13.4% vs 3.5,P < 0.001),alanine aminotransferase(-110.7 IU/L vs-10.6 IU/L,P = 0.047),total cholesterol(-18.1 mg/d L vs 3.8 mg/d L,P = 0.016),and triglyceride levels(-61.3 mg/d L vs 11.2 mg/d L,P = 0.013) were significantly decreased only in the compliant group.The change in body mass index and dual-echo fat fraction showed a positive correlation(ρ = 0.418,P = 0.030).CONCLUSION: Hepatic fat quantification MR can be a non-invasive,quantitative and useful tool for monitoring treatment effects in pediatric NASH.

Sex-specific Cutoff Values of Visceral Fat Area for Lean vs. Overweight/Obese Nonalcoholic Fatty Liver Disease in Asians

Background and Aims:Visceral obesity is a risk factor for nonalcoholic fatty liver disease(NAFLD).We investigated sex-specific optimal cutoff values for visceral fat area(VFA)associated with lean and overweight/obese NAFLD in an Asian population.Methods:This retrospective study includ-ed 678 potential living liver donors(mean age,30.8±9.4 years;434 men and 244 women)who had undergone ab-dominal computed tomography(CT)imaging and liver bi-opsy between November 2016 and October 2017.VFA was measured using single-slice abdominal CT.NAFLD was eval-uated by liver biopsy(≥5%hepatic steatosis).Receiver op-erating characteristic curve analysis was used to determine cutoff values for VFA associated with lean(body mass index[BMI]<23 kg/m2)and overweight/obese(BMI≥23 kg/m2)NAFLD.Results:Area under the curve(AUC)values with 95%confidence intervals(CI)for VFA were 0.82(95%CI,0.75-0.88)for lean and 0.74(95%CI,0.69-0.79)for over-weight/obese men with NAFLD.The AUC values were 0.67(95%CI,0.58-0.75)for lean and 0.71(95%CI,0.62-0.80)for overweight/obese women with NAFLD.The cutoff values for VFA associated with lean NAFLD were 50.2 cm2 in men and 40.5 cm2 in women.The optimal cutoff values for VFA associated with overweight/obese NAFLD were 100.6 cm2 in men and 68.0 cm2 in women.Conclusions:Sex-specific cutoff values for VFA may be useful for identifying subjects at risk of lean and overweight/obese NAFLD.