应用肝体外模型评价B1-T1 mapping的直方图研究

Histogram study on assessment B1-T1 mapping using hepatic vitro model

目的探讨在体外模型中评价B1-T1 mapping序列在诊断肝纤维化分级中的价值。方法应用3D打印技术制备肝脏体外模型的外壳,以三种不同比例的明胶与水混合物,分次灌注入体外模型中,以模拟轻、中、重度的肝纤维化状态。对此模型分别行T1 mapping序列和B1-T1 mapping序列扫描。采用Image J软件提取体外模型的T 1值,用SPSS软件进行直方图分析;应用受试者操作特征(ROC)曲线及DeLong法评价T1 mapping序列和B1-T1 mapping序列对不同分级肝纤维化体外模型的诊断效能。结果不同分级的肝纤维化体外模型分别行T1 mapping序列和B1-T1 mapping序列扫描后,T1mapping序列均值和峰度鉴别不同分级肝纤维化模型的AUC分别为0.831(95%CI:0.712,0.916)及0.788(95%CI:0.663,0.788);B1-T1 mapping序列均值和峰度鉴别不同浓度肝纤维化模型的AUC分别为0.952(95%CI:0.864,0.991)及0.637(95%CI:0.503,0.758)。DeLong法对ROC曲线进行两两比较,均值在不同程度肝纤维化模型的比较差异具有统计学意义(P<0.05)。结论T1 mapping序列和B1-T1 mapping序列所得到的T 1值是不同的,采用B1-T1 mapping序列扫描所得全肝T 1值具有更高鉴别不同分级肝纤维化的能力,临床实用价值更高。

Objective To evaluate the value of B1-T1 mapping sequence in the diagnosis of liver cirrhosis in vitro model.Methods The shells of the in vitro liver models were prepared by 3D printing technology,and three different ratios of gelatin and water mixtures were injected into the in vitro models to simulate mild,moderate and severe liver fibrosis states.The model was scanned with T1 mapping sequence and B1-T1 mapping sequence,respectively.The T 1 values of the in vitro models were extracted by Image J software,and histogram analysis was performed by SPSS software;the diagnostic efficacy of T1 mapping sequence and B1-T1 mapping sequence for different grades of liver fibrosis in vitro models was evaluated by applying the subject operating characteristic(ROC)curve and delong method.Results After the T1 mapping sequence and B1-T1 mapping sequence were scanned in vitro for different grades of liver fibrosis models,the AUCs of T1 mapping sequence mean and kurtosis to identify different grades of liver fibrosis models were 0.831(95%CI:0.712,0.916)and 0.788(95%CI:0.663,0.788),respectively.The AUCs of B1-T1 mapping sequence mean and kurtosis to identify different concentrations of liver fibrosis models were 0.952(95%CI:0.864,0.991)and 0.637(95%CI:0.503,0.758),respectively,with statistical significance(P<0.05).Conclusion The T 1 values obtained by T1 mapping sequence and B1-T1 mapping sequence are different,and the whole liver T 1 values obtained by scanning with B1-T1 mapping sequence have a higher ability to identify different grades of liver fibrosis and are of higher clinical utility.