Extended Tofts模型的DCE-MRI功能成像参数评价肝硬化的价值

Value of DCE-MRI Parameters with Extended Tofts Model in Evaluation of Liver Cirrhosis

目的探讨动态对比增强磁共振（DCE-MRI）功能成像参数评价肝硬化的价值。方法搜集经临床、生化、影像学检查和肝脏穿刺活检筛选并符合入组和排除标准的20例代偿期肝硬化患者、15例失代偿期肝硬化患者的临床资料以及正常对照组15名健康志愿者,均行肝脏DCE-MRI扫描。选择Extended Tofts血流动力学双室模型获得各组定量灌注参数,包括肝脏总灌注量（FP）、门静脉灌注量（PVP）、肝动脉灌注量（HAP）、肝动脉灌注指数（HPI）、对比剂平均通过时间（MTT）、达峰时间（TTP）、血容量（BV）。三组数据间的差异采用单因素方差分析,组间两两比较采用LSD检验。定量参数与肝硬化程度的相关性采用秩相关分析,绘制受试者工作特征曲线（ROC）判断定量参数对肝硬化的诊断效能。结果正常组、代偿期和失代偿期肝硬化组HPI值分别为（0.34±0.09）、（0.57±0.17）和（0.76±0.20）,MTT值分别为（17.38±15.38）s、（34.26±11.37）s和（57.33±16.73）s,TTP值分别为（5.7±1.3）s、（8.3±1.2）s和（13.6±3.5）s,差异均具有统计学意义,且三组间两两比较均有统计学差异（P〈0.05）。正常组、代偿期和失代偿期肝硬化组FP值分别为（128.3±21.8）ml·min^-1·100g-1、（109.8±18.9）ml·min^-1·100g-1和（63.7±23.5）ml·min^-1·100g-1,PVP值分别为（101.3±24.5）ml·min^-1·100g-1、（72.6±21.4）ml·min^-1·100g-1和（45.8±17.8）ml·min^-1·100g-1,差异均具有统计学意义（P〈0.05）,且三组间两两比较均有统计学差异（P〈0.05）。正常组、失代偿期肝硬化组HAP值分别为（23.5±12.7）ml·min^-1·100g-1、（38.4±14.6）ml·min^-1·100g-1,二者之间差异具有统计学意义（P〈0.05）。PVP、FP与肝硬化严重程度呈负相关（r=-0.920、-0.824,P〈0.05）;HAP、HPI、MTT、TTP与肝硬化严重程度呈正相关（r=0.592、0.863、0.859、0.784,P〈0.05）。ROC曲线判断HPI和MTT对代偿期和失代偿期肝硬化均具有较高的诊断效能。结论 Extended Tofts模型的DCE-MRI功能成像参数能够整体、客观地反映肝硬化的血流动力学改变,可用于评估和预测肝硬化的严重程度。

Objective To investigate the value of dynamic contrast-enhanced magnetic resonance imaging（ DCE-MRI）parameters with Extended Tofts model in liver cirrhosis. Methods A total of 35 patients with 20 compensatory liver cirrhosis,15 decompensatory liver cirrhosis,who were confirmed by clinical symptoms,imaging and liver biopsy,and 15 healthy volunteers were prospectively enrolled and performed liver DCE-MRI. Quantitative perfusion parameters of three groups were obtained by Extended Tofts model,including full perfusion（ FP）,portal venous perfusion（ PVP）,hepatic arterial perfusion（ HAP）,hepatic arterial perfusion index（ HPI）,mean transit time（ MTT）,time to peak（ TTP）,blood volume（ BV）.The parameters of three groups were compared with one-way ANOVA and LSD test for every two groups. Spearman rank test was used to analyze the correlation between quantitative parameters and liver cirrhosis. The diagnostic efficacy of parameters were analyzed by using ROC. Results The HPI,MTT and BF values in the control group,the compensatory cirrhosis group and decompensatory cirrhosis group were（ 0. 34 ± 0. 09）,（ 0. 57 ± 0. 17） and（ 0. 76 ± 0. 20）;（ 17. 38 ± 15. 38） s,（ 34. 26 ± 11. 37） s and（ 57. 33 ± 16. 73） s;（ 5. 7 ± 1. 3） s,（ 8. 3 ± 1. 2） s and（ 13. 6 ± 3. 5） s,respectively,showing a significant difference among three groups,as well as significance between every two groups（ P 〈 0. 05）. The FP and PVP values in three groups were（ 128. 3 ± 21. 8） ml·min^-1·100 g^-1,（ 109. 8 ± 18. 9） ml·min^-1·100 g^-1 and（ 63. 7 ± 23. 5）ml·min^-1·100 g^-1;（ 101. 3 ± 24. 5） ml·min^-1·100 g^-1,（ 72. 6 ± 21. 4） ml·min^-1·100 g^-1 and（ 45. 8 ± 17. 8） ml·min^-1·100 g^-1,showing a significant difference among three groups,as well as significance between every two groups（ P〈 0. 05）. The HAP value in the control group and decompensatory cirrhosis group were（ 23. 5 ± 12. 7） ml · min^-1·100 g^-1 and（ 38. 4 ± 14. 6） ml·min^-1·100 g^-1 with a significant difference（ P 〈 0. 05）. PVP and FP were negatively correlated with degree of live cirrhosis（ r =-0. 920,-0. 824,P 〈 0. 05）,while HAP,HPI,MTT and TTP were positively correlated with degree of live cirrhosis（ r = 0. 592,0. 863,0. 859,0. 784,P 〈 0. 05）. HPI and MTT showed high efficiency in diagnosis of compensatory and decompensatory liver cirrhosis according to ROC. Conclusion The parameters of DCEMRI quantitative study with Extended Tofts model could integrally and objectively reflect hemodynamic changes of liver cirrhosis,and could evaluate and predict severity of liver cirrhosis.