ABSTRACT
Objective To explore the value of dynamic contrast-enhanced MRI (DCE-MRI)with Exchange model in the quantitative evaluation of liver fibrosis.Methods Liver DCE-MRI was performed on 85 patients with chronic hepatitis confirmed by liver aspiration biopsy.Quantitative parameters,including volume transfer constant of the contrast agent (Ktrans),reverse reflux rate constant (Kep),volume fraction of EES (Ve),volume fraction of plasma (Vp),full perfusion (FP),portal venous perfusion (PVP),hepatic arterial perfusion (HAP),hepatic arterial perfusion index (HPI),mean transit time (MTT),time to peak (TTP) and blood volume (BV)were obtained by Exchange model.The parameters of each stage were compared by A N OVA analysis and LSD test was used for comparison between groups.Spearman rank correlation analysis was used to analyze the relationship between quantitative parameters and liver fibrosis stages.The diagnostic efficacy of Ktrans,Ve,HPI and MTT were analyzed by receiver operating curve (ROC).Results Ktransdecreased in all stages of liver fibrosis and Ve decreased in the late stages (S3 and S4)(P＜0.05).FP and PVP decreased in all stages and HAP increased in the late stage (P＜0.05);HPI,MTT and TTP increased in all stages,there were statistic differences between every two stages (P＜0.05).Ktrans and Ve were negatively correlated with live fibrosis staging (r=-0.837,-0.726, P＜0.05);PVP and FP were negatively correlated with live fibrosis staging (r=-0.927,-0.864,P＜0.05);HAP,HPI,MTT and TTP were positively correlated with live fibrosis staging (r=0.622,0.873,0.906,0.852,P＜0.05).Ktrans showed high sensitivity and specificity in diagnosis of ≥S2,≥S3 and S4 liver fibrosis;HPI and MTT showed high sensitivity,specificity and efficiency in diagnosis of every stage of liver fibrosis.Conclusion The quantitative study of DCE-MRI with Exchange model can be used for diagnosis and staging of liver fibrosis.
ABSTRACT
Objective To investigate the value of dynamic contrast-enhanced MRI (DCE-MRI) quantitation study with exchange model in evaluation of liver cirrhosis.Methods A total of 30 patients with liver cirrhosis confirmed to included and excluded criteria were divided into compensatory cirrhosis group (n=15) and decompensatory cirrhosis group (n=15).And 15 healthy volunteers were scrvcd as a control group.All subjects were performed liver DCE-MRI and quantitative pa rameters of three groups were obtained by exchange model,including volume transfer constant of the contrast agent (Ktrans),reverse reflux rate constant (Kep),volume fraction of EES (Ve),volume fraction of plasma (Vp),arterial perfusion index (HPI),blood volume (BV),blood flow(BF) and mean transit time (MTT).The parameters of three groups were compared by ANOVA analysis and LSD test for every two groups.The diagnostic efficacy of Ktrans,Ve,HPI,MTT for liver cirrhosis were analyzed by ROC.Results Ktrans,Ve,HPI,MTT and BF values in the control group,compensatory cirrhosis group and decompensatory cirrhosis group were (0.85 ± 0.34) min-1,(0.67 ± 0.36) min-1,(0.39±0.18)min-1;0.47±0.42,0.34±0.13,0.16±0.06;0.35±0.09,0.57±0.17,0.76±0.20;(17.38±15.38)s,(34.26111.37)s,(57.33±16.73)s;(97.22±36.29)ml/(min· 100 g),(69.30±35.22)ml/(min· 100 g),(24.64± 28.24) ml/(min · 100 g),respectively,and showing significant differences among three groups,and significant with HPI and MTT for every two groups (P＜0.05).There were no significant differences for Kep,Vp and BV among three groups (P＞0.05).According to ROC of Ktrans and Ve for decompensatory liver cirrhosis,AUC were 0.86,0.92,the sensitivity were 90％,90％ and the specificity were 80％,80％.According to ROC of HPI and MTT for compensatory liver cirrho sis,AUC were 0.79,0.76,the sensitivity were 85％,85％ and the specificity were 75％,75％.According to ROC of HPI and MTT for decompensatory liver cirrhosis,AUC were 0.91,0.88,the sensitivity were 95％,90％ and the specificity were 80％,80％.Conclusion DCE-MRI quantitative study with exchange model can obtain multiple parameters,refleet hemodynamic changes and vascular microenvironment and evaluate severity of liver cirrhosis.