Study Of Diffusion Kurtosis Imaging For Assessing Liver Cancer And Peritumoral Area In Pre-and Post-theropy

Objective To study the value of diffusional kurtosis imaging(DKI)to assess tumour cell invasion of peritumoral area before therapy and pathologic changes of non-tumoral liver parenchyma in pre-and post-TACE.Material and Methods This research belonged to prospective study which includes 41 patients(male 35 cases,female 6 cases,age from 26 to 68 years old,average age 50.5 years)with liver cancer which classed as pathology group(12cases),non-pathology group(29 cases)and TACE group(6 cases).12 cases healthy volunteers elected as control group(male 8 cases and female 4cases,age from 21 to 31 years,mean age 24.9 years).All cases underwent DKI(directions=25;b=0,500,1000 s/mm2)and MRI plain scan,and at the same time 9 patients underwent special contrast enhanced MR scan(GD-EOB-DTPA),15 patients underwent normal contrast enhanced scan(GD-DTPA)and 17 patients and 12 healthy people underwent MRI plain scan.3 region of interests(acreage about 100mm2)was positioned in liver cancer,3 ROIs in peritumoral area and 4 ROIs in distant liver parenchyma(far away from the tumor>2 cm).Fractional anisotropy(FA),mean diffusion(MD),axial diffusivity(Da),radial diffusivity(Dr),mean kurtosis(MK),axial kurtosis(Ka)and radial kurtosis(Kr)value of all groups were recorded through post-processed software FUNCTOOl.All the datas were analyzed by the statistical software SPSS17.0.The differences of DKI parameters were evaluated using one-way analysis of variance(ANOVA),LSD was applied to multiple comparison in group;the differences of DKI parameters of peritumoral liver parenchyma and distant liver parenchyma between pathology group and non-pathology group were compared by two samples t test;pare-samples T test was apply to compare pre-and post-TACE.The significance level is 0.05.Results(1)The signal of liver cancer in MR plain scan showed mild long T1 and mild long T2 signal,and fast in and fast out enhanced feature of the neoplasms can be observed from the enhanced MRI.The signal of liver cancer in DKI would not decrease with increased b values.(2)The differences of DKI parameters including MD,Da,Dr and Ka value have significant statistical differences in normal liver parenchyma,the distant liver parenchyma,peritumoral liver parenchyma and liver cancer,while MK and Kr value have not statistical differences.MD,Da and Dr value of normal parenchyma were higher than that of non-tumoral liver parenchyma and liver cancer,while the Ka value was reverse.The differences of MD,Da,Dr and Ka value only had no statistical significance between the distant liver parenchyma and peritumoral liver parenchyma(P>0.05),while the differences of these parameters in remaining group have statistical significances(P<0.05).(3)The difference between peritumoral liver parenchyma and distant liver parenchyma of pathology group and non-pathology group has no statistical significance.(4)There are statistical differences in MD,Da and Dr value of post-TACE compared with pre-TACE.The all DKI parameters have no statistical differencesbetween peritumoral liver parenchyma and distant liver parenchyma after TACE,and no statistical differences of DKI parameters can be seen from distant liver parenchyma between pre-and post-TACE group.Conclusions(1)The DKI quantitative parameters(MD,Da,Dr and Ka value)can reflect the water molecular diffussional differences of different tissues which include liver cancer,non-tumoral liver parenchyma and normal liver parenchyma.(2)DKI can provide molecular imaging information for evaluating liver cancer and tumoral cell invasion of peritumoral zone.(3)The DKI quantitative parameters(MD,Da and Dr value)may be the sensitive biomarkers which can instantly reflect the microstructural changes of non-tumoral liver parenchyma after TACE.