家兔脂肪肝超声背向散射积分研究

目的建立不同程度家兔脂肪肝模型，进行肝超声背向散射积分（IBS）测定，为IBS诊断脂肪肝提供参考依据。方法选用40只纯种新西兰家兔，采用高脂高糖饲料加酒精饮料建立不同程度脂肪肝模型，并设立对照组。应用HPSonos5500超声诊断仪实时检测肝IBS，包括图像平均强度（AⅡ）、峰峰强度及图像强度标准差，并计算散射信号衰减比率。结果正常家兔AⅡ肝右叶显著低于肝左叶（P〈0．01）；脂肪肝标化AⅡ随病变加重呈递增趋势，正常肝〈轻度脂肪肝〈中度脂肪肝〈重度脂肪肝，尤以近区为著（P〈0．0001）；同等程度肝脂肪变性IBS值随炎症和纤维化的发生而增大。轻、中、重度脂肪肝远、近区AⅡ比较，衰减比率依次为肝左叶5．30dB／cm、8．58dB／cm和7．41dB／cm（P〈0．0001），肝右叶6．72dB／cm、7．31dB／cm和1（1．03dB／cm（P=0．0014）。结论超声IBS值与散射信号衰减比率可反映肝的脂肪积累和炎症病变程度，为IBS判断脂肪肝病变程度提供客观依据。

Study of ultrasonic integrated backscatter on experimental hepatic steatosis model in rabbits

Objective To establish the reliable non-invasive ultrasonic diagnostic criteria of fatty liver diseases in rabbit models with various degrees of hepatic steatosis,and measure ultrasonic integrated backscatter(IBS).Methods Forty healthy New Zealand rabbits were randomly divided into normal control and three experimental groups.Hepatic steatosis models were established by giving high fat,high sugar diet with drinking water containing five percent ethanol.The grading of steatosis and inflammation,stages of fibrosis of the rabbits were evaluated as simple steatosis,steatohepatitis,fibrosis and cirrhosis,based on Sudan IV,HE staining,Masson trichrome staining.Liver IBS [average image intensity(AII),peak-peak intensity and standard deviations of image] were measured using HP Sonos 5500 and analyzed with one-way ANOVA.Results All of the experimental rabbits developed fatty livers,which included 10 mild,11 moderate and 9 severe hepatic-steatosis.There were significant differences of AII between the left and right hepatic lobes of health rabbits((P<)(0.01)).Significantly increased hepatic AII was associated with aggravated hepatic steatosis,i.e.,normal control< mild fatty liver< moderate fatty liver