An Application Study Of Hepatic Fibrosis And Inflammatory Activity In Chronic Hepatitis B With Multi-models Of Diffusion-weighted MR Imaging

Part I An application study in the diagnosis of hepatic fibrosis in chronic hepatitis B with multi-models of diffusion-weighted MR imaging Purpose:The purpose of our study is to explore and compare the application value of monoexponential,biexponential and stretched exponential DWI models in the diagnosis of hepatic fibrosis in patients with chronic hepatitis B(CHB).Materials and Methods:52 patients with chronic HBV and 30 healthy subjects had undergone prospective routine MRI and muti-b values DWI on a 3.0-T magnetic resonance imaging(MRI)unit.DWI with parallel imaging technique was accomplished by means of a respiratory-triggered single-shot spin-echo sequence with 13 b-values(0,50,100,150,200,300,500,800,1000,1300,1500,1700 and 2000 sec/mm2).DWI data were processed by monoexponential,biexponential and stretchedexponential DWI models on a workstation.The standard apparent diffusion coefficient(ADCst)was calculated by using a monoexponential DWI model.The pseudo diffusion coefficient(Dp)perfusion fraction(f)and true diffusion coefficient(Dt),were calculated by using biexponential DWI model.The distributed diffusion coefficient(DDC)and water molecular diffusion heterogeneity index(?)were calculated by using a stretched-exponential DWI model.All the 52 patients had a definite history of Hepatitis B virus infection,and the infection history was more than 6 months.All the patients underwent the ultrasound guided liver biopsy after the MRI examation and obtained the pathological results.The stage of hepatic fibrosis was according to the internationally available Scheuer scoring system.The Mann-Whitney U test was adopted to compare each parameter between the study group and the control group.The Wilcoxon signed rank test was adopted to compare ADCst with Dt values calculated fromhepatic fibrosis patients and normal volunteers.Spearman rank correlation coefficient was used to assess the correlation of between ADCst and DDC values,Dt and DDC values of hepatic fibrosis patients,respectively.ROC analysis was used to evaluate the performance of various diffusion parameters in predicting the presence hepatic fibrosis.Results:1.ADCst,Dt,f and DDCvalues of the liver showed significantly different between the hepatic fibrosis group and the healthy control group(all P<0.001).The ADCst,Dt,f and DDC values of the liver were significantly higher in the healthy control group than in the hepatic fibrosis group.However,Dp and ? values of the liver showed no signicantly different between the hepatic fibrosis group and the healthy control group(P>0.05)2.Dt value was signicantly lower than ADCst in both the hepatic fibrosis group and the healthy control group(0.592×10-3 mm2/s vs 0.898×10-3 mm2/s,0.705×10-3 mm2/s vs 0.985×10-3 mm2/s,all P<0.001).3.There was a strong positive correlation between ADCst and DDC values in all the hepatic fibrosis patients(r=0.794,P<0.001).There was a moderate positive correlation between DDC and Dt values in all the hepatic fibrosis patients(r=0.456,P<0.05).4.Dt value had the highest AUC(0.826)in discriminating the liver of hepatic fibrosis group from the healthy control group,followed by DDC(0.822),f(0.788),ADCst(0.770).However,there were not statistically significant for Dp and ? values in diagnosing hepatic fibrosis(P > 0.05).Conclusion:1.The Dt value was signicantly lower than ADCst value in both the hepatic fibrosis group and the healthy control group,which indicated that the microcirculation perfusion had some influence on the ADCst value.2.The Dt value from the biexponential model showed the highest diagnostic efficiency in diagnosing hepatic fibrosis in chronic hepatitis B,followed by DDC value from stretched exponential model,and both Dt and DDC values outperformed ADCst value from momoexponential model in diagnosing hepatic fibrosis in chronic hepatitis B.3.As a new noninvasive method for quantitative detection of hepatic fibrosis,the biexponential and stretched exponential models of DW-MRl had important value in diagnosing hepatic fibrosis in chronic hepatitis B.Part IIAn application study in the stage of hepatic fibrosis in chronic hepatitis B with multi-models of diffusion-weighted MR imaging Purpose:To quantitatively compare the ability of various diffusion parameters obtained from monoexponential,biexponential and stretched exponential DWI models in assessing hepatic fibrosis in patients with CHB.Materials and Methods:52 patients with CHB had undergone prospective routine MRI and muti-b values DWI on a 3.0-T magnetic resonance imaging(MRI)unit.DWI with parallel imaging technique was performed by using a respiratory-triggered single-shot spin-echo planar sequence with 13 b-values(0~2000sec/mm2).DWI data were processed by monoexponential,biexponential,stretched exponential DWI models on a workstation.ADCst was calculated by using the monoexponential DWI model.Dp,f and Dt were calculated by using the biexponential DWI model.DDC and ? were calculated by using the stretched-exponential DWI model.All the 52 patients had a definite history of Hepatitis B virus infection,and the infection history was more than 6 months.All the patients underwent the ultrasound guided liver biopsy after the MRI examation and obtained the pathological results.The stage of hepatic fibrosis was according to the internationally available Scheuer scoring system.The Mann-Whitney U test was adopted to compare each parameter between the fibrosis stage groups.The Mann-Whitney U test was also adopted to compare each parameter between the fibrosis stage?S1 and ?S2,between stage ?S2 and ?S3.The Kruskal-Wallis test was employed for the comparison of each parameter among the fibrosis stage groups.Spearman rank correlation coefficient was obtained to assess the correlation of all the parameters with the fibrosis stage.ROC analysis was used to evaluate the performance of various diffusion parameters in predicting the presence of the fibrosis stage?S2 and ?S3.Results:1.ADCst,Dt and DDC showed a moderate negative correlation with the fibrosis stages(r=-0.464,-0.630 and-0.603,respectively,all P<0.001),and f showed a mild positive correlation with the fibrosis stage(r=-0.379,P<0.05).ADCst,Dt,f and DDCvalues all decreased with the increase of fibrosis stage.While Dp and ? values of the liver showed no signicantly correlation with the fibrosis stages.2.The difference of ADCst,Dt,f and DDC values between the control group and group S2,S3,S4,between group S1 and S4 were significant(P<0.05);The difference of ADCst,Dt and DDC values between group S2 and S4 were significant(P<0.05);The difference of Dt and DDC values between group S1 and group S2,S3 were significant(P<0.05);The difference of ADCst,Dt values between group S3 and S4 were significant(P<0.05);While the difference of ADCst,Dt,f and DDC values between the control group and group S1,between group S2 and S3 were not significant(P>0.05).3.The ADCst,Dt,f and DDC values were significantly lower in significant fibrosis(?S2)than in no or early fibrosis(?S1)(P<0.05),the AUCs of ADCst,Dt,f and DDC values for detecting fibrosis stage ?S2were 0.738,0.835,0.740 and 0.811.the AUCs of ADCst,Dt,f and DDC values were significantly lower in fibrosis stage?S3 than in stage?S2(P<0.05),the AUCs of ADCst,Dt,f and DDC values for detecting fibrosis stage?S3 were 0.716,0.811,0.672 and 0.798.Dt had the highest AUC in diagnosing fibrosis stage?S2 and stage?S3,followed by DDC.The AUC of f value for detecting fibrosis stage?S2 was slightly greater than the AUC of ADCst,while the AUC of f value for detecting fibrosis stage?S3 was slightly less than the AUC of ADCst.Conclusion:1.The ADCst value from the monoexponential model,the Dt and f value from the biexponential model,and DDC value from the stretched exponential model all showed a negative correlation a negative correlation with thefibrosis stage.2.The Dt value from the biexponential model showed the highest diagnostic efficiency in diagnosing hepatic fibrosis stage ?S2 and ?S3,followed by DDC from stretched exponential model,and both Dt and DDC values outperformed ADCst from momoexponential model.3.As a new noninvasive method for quantitative assessment the stage of hepatic fibrosis in patients with hepatitis B,the biexponential and stretched exponential models of DW-MRl had important value in the hepatic fibrosis grading.Part III An application study in the grade of inflammatory activity in chronic hepatitis B with multi-models of diffusion-weighted MR imaging Purpose:To quantitatively compare the ability of various diffusion parameters obtained from monoexponential,biexponential and stretched exponential models in assessing hepatic inflammatory activity in patients with CHB.Materials and Methods:52 patients with CHB had undergone prospective routine MRI and muti-b values DWI on a 3.0-T magnetic resonance imaging(MRI)unit.DWI with parallel imaging technique was performed by using a respiratory-triggered single-shot spin-echo planar sequence with 13 b-values(0~2000 sec/mm2).DWI data were processed by monoexponential,biexponential and stretched exponential DWI models on a workstation.ADCst was calculated by using a monoexponential DWI model.Dp,f and Dt were calculated by using biexponential DWI model.DDC and ? were calculated by using a stretched-exponential DWI model.All the 52 patients had a definite history of Hepatitis B virus infection,and the infection history was more than 6 months.All the patients underwent the ultrasound guided liver biopsy after the MRI examation and obtained the pathological results.The grade of inflammatory activity was according to the internationally available Scheuer scoring system.The Mann-Whitney U test was adopted to compare each parameter between the inflammatory activity grade groups.The Mann-Whitney U test was also adopted to compare each parameter between the inflammatory activity grade?G1and?G2,between the grade ?G2 and ?G3.The Kruskal-Wallis test was employed for the comparison of each parameter among the inflammatory activity grade groups.Spearman rank correlation coefficient was obtained to assess the correlation of all the parameters with the inflammatory activity grade of HF,respectively.ROC analysis was used to evaluate the performance of various diffusion parameters in predicting the presence of the inflammatory activity grade?G2 and ?G3.Results:1.ADCst,Dt and DDC showed a moderate negative correlation with the inflammatory activity grade(r=-0.532,-0.571 and-0.627,respectively,all P< 0.001),and f showed a mild positive correlation with the inflammatory activity grade(r=-0.281,P<0.05).ADCst,Dt,f and DDCvalues all decreased with the increase of inflammatory activity grades.While Dp and ? values of the liver showed no signicantly correlation with the inflammatory activity grades.2.The difference of ADCst,Dt,f,DDC values between the control group and group G2,G3,G4 were significant(P<0.05);The difference of ADCst,Dt and DDC values between the group G1 and G3,G4,between the group G2 and G3,G4 were significant(P<0.05);The difference of Dt,DDC values between the group G1 and G2 were significant(P<0.05);While the difference of ADCst,Dt,f and DDC values between the control group and group G1,between group G3 and G4 were not significant(P>0.05).3.The ADCst,Dt and DDC values were significantly lower in inflammatory activity grade?G2 than?G1(P<0.05),the AUCs of ADCst,Dt and DDC values for detecting inflammatory activity grade?G2 were 0.814,0.902 and 0.859.The ADCst,Dt and DDC values were significantly lower in inflammatory activity grade?G3 than?G2(P<0.05),the AUCs of ADCst,Dt and DDC values for detecting inflammatory activity grade?G3 were 0.786,0.817 and 0.800.Dt had the highest AUC in diagnosing inflammatory activity grade?G2 and?G3,followed by DDC,ADCst.Conclusion:1.The ADCst value from the monoexponential model,the Dt and f value from the biexponential model,and DDC value from the stretched exponential model all showed a negative correlation with the inflammatory activity grades.2.The Dt value showed the highest diagnostic efficiency in diagnosing inflammatory activity grade?G2 and ?G3,followed by DDC,and both Dt and DDC values outperformed ADCst.3.As a new noninvasive method for quantitative assessment of hepatic inflammatory activity in patients with hepatitis B,the biexponential and stretched exponential models of DW-MRl had important value in the hepatic inflammatory activity grading.