定量CT测量动物肝脏脂肪含量的实验研究

Fat content measurement of animal livers using quantitative computed tomography

目的:以Soxhlet化学萃取法的测量结果为参考标准,探讨定量CT(QCT)对离体动物肝脏标本脂肪含量测量的准确性。方法:选取5块猪肝、5块鹅肝和10块鸭肝,分别使用QCT和Soxhlet化学萃取法测量每个样本的脂肪含量。对QCT测得的肝脏脂肪含量(Fat%Q)和Soxhlet化学萃取法测得的肝脏脂肪含量(Fat%S)进行比较,并使用线性回归分析研究Fat%Q与Fat%S之间的关系。结果:Soxhlet化学萃取法测得的猪肝、鸭肝和鹅肝的脂肪含量分别为0.5%~2.3%、7.2%~21.0%和35.0%~52.6%,QCT测得的肝脏脂肪含量低于Soxhlet化学萃取法,但两种方法的测量结果差异无统计学意义(P=0.052)。两种方法的测量结果高度相关(r=0.962,P<0.001),Fat%S可以通过线性方程Fat%S=0.74,Fat%Q+7.272(r2=0.965,P<0.001)进行预测。结论:以化学Soxhlet萃取法作为验证参考标准,使用常规CT和QCT体模能够准确测量离体动物肝脏样本的脂肪含量。

Objective：To study the fat content measurement of animal livers in vitro by quantitative computed tomography （QCT） using chemical Soxhlet extraction technique as the standard reference. Methods： Five pig livers,5 goose livers and 10 duck livers were collected and QCT as well as chemical Soxhlet extraction were used individually to measure fat content for each sample. Fat percentage of all samples determined by QCT （Fat%QCT） and by Soxhlet chemical extraction （Fat%Soxhlet） was compared. Furthermore,linear regression analysis was used to detect the relationship between Fat%QCT and Fat%Soxhlet. Results：The fat percentage of pig liver,duck liver and goose liver measured by chemical extraction ranged from 0.5% to 2.3% ,7.2% to 21% ,and 35% to 52.6% respectively. The fat content of liver measured by QCT was lower than that measured by chemical Soxhlet extraction method,but there was no statistical significant difference between results of two methods （P = 0.052）. The two measurements were highly correlated （r = 0. 962, P 〈 0. 001 ）. Fat % Soxhlet could be predicted by Fat %0 QCT with the equation as： Fat %So xhlet = 0.74 Fat % QCT ＋ 2. 272 （r2 = 0. 965,P 〈 0. 001）.Conclusion：Fat content of animal liver can be measured accurately with a conventional computed tomography （CT） scanner with QCT phantom and software compared to the chemical Soxhlet extraction as standard reference.