能谱CT基物质分离技术在肝硬化与正常肝脏血流定量研究中的应用

目的:探讨能谱CT基物质分离技术在Child-Pugh A级肝硬化与正常肝脏血流动力学定量研究中的应用价值。方法:收集临床确诊肝硬化Child-Pugh A级并行上腹部增强CT检查患者30例作为肝硬化组，同时收集肝脏及门静脉增强CT检查无异常患者30例作为正常肝脏组。两组均采用能谱CT扫描并重建70 keV单能量图像、碘基物质分离图像，在70 keV、碘基图像上分别测量动脉期（AP）和门静脉期（PV）肝脏五叶（肝尾状叶、肝左外叶、肝左内叶、肝右前叶、肝右后叶）CT值和碘浓度（IC），计算动脉期碘分数(AIF)和门静脉期碘含量（PVIC）。采用独立样本t检验比较两组能谱参数，并运用ROC曲线分析各参数诊断效能。结果:肝硬化组动脉期CT值和碘浓度与正常肝脏组无统计学差异（P>0.05），而门静脉期CT值和碘浓度显著低于正常肝脏组（P<0.05）。肝硬化组肝脏AIF稍高于正常肝脏组（P>0.05），而肝脏PVIC均显著低于正常肝脏组（P<0.05）。以门静脉期肝脏平均碘浓度21.47 mg/mL为阈值评价肝硬化与正常肝脏血流时，ROC曲线下面积（AUC）为0.790，敏感度为77.8%，特异度为83.3%，显著高于肝脏CT值和PVIC。结论:能谱CT基物质分离技术可以用来评价肝硬化与正常肝脏血流动力学的改变和差异，为肝硬化的早期诊断提供更多依据。

Application of basis material decomposition technique with energy spectral CT in the quantitative study on blood flows in cirrhotic liver and healthy liver

Abstract: Objective To evaluate the application value of basis material decomposition technique with energy spectral CT in the quantitative study of blood flows in Child-Pugh A cirrhotic liver and healthy liver. Methods Thirty patients who were diagnosed with Child-Pugh A liver cirrhosis and examined with upper-abdomen enhanced CT were enrolled as liver cirrhosis group, while 30 subjects without any abnormality in the enhanced CT examination of liver and portal vein were selected as healthy liver group. All patients underwent energy spectral CT imaging, and the images of 70 keV monochromatic energy and iodine-based material decomposition were reconstructed. The CT values and iodine concentrations of different liver lobes (caudate lobe, left lateral lobe, left inner lobe, right anterior lobe and right posterior lobe) were measured on 70 keV monochromatic energy and iodine-based material decomposition images in both arterial phase and portal venous phase. The arterial iodine fraction and portal venous iodine concentration (PVIC) of the liver were also calculated. These spectral parameters between two groups were compared with independent sample t test. Finally, receiver operating characteristic curve was used for analyzing the diagnostic performance of each spectral parameter. Results The CT values and iodine concentrations of liver cirrhosis group in the arterial phase were similar to those of healthy liver group (P>0.05), but the CT values and iodine concentrations of liver cirrhosis group in the portal venous phase were significantly lower than those of healthy liver group (P<0.05). Compared with healthy liver group, liver cirrhosis group had slightly higher arterial iodine fractions (P>0.05) and significantly lower PVIC (P<0.05). The average iodine concentration of liver in the portal venous phase which was 21.47 mg/mL was used as the threshold value to evaluate the blood flow between cirrhotic liver and healthy liver, the area under receiver operating characteristic curve was 0.790, with a sensitivity of 77.8% and a specificity of 83.3%, which was significantly higher than the diagnostic performance of CT values and PVIC. Conclusion The basis material decomposition technique with energy spectral CT can be used to assess the hemodynamic changes and differences between cirrhotic liver and healthy liver, providing more evidence for the early diagnosis of liver cirrhosis.