A Comparative Study On Diffusion Weighted Imaging Of Hepatocellular Carcinoma,Para-carcinoma Tissues,Far-Cancer Liver Parachyma And Background Liver Parachyma

Objective:To investigate the differences in apparent diffusion coefficient(ADC)and exponential apparent diffusion coefficient(eADC)on high field 1.5T MRI of diffusion weighted imaging(DWI)among hepatocellular carcinoma(HCC),para-cancer tissue,far-cancer liver parachyma and background liver parachyma.Methods:Seventy-five consecutive patients with HCC confirmed by surgery and puncture pathology in our hospital from January 2018 to December 2020 were enrolled.The ADC and eADC of HCC,para-cancer tissue,far-cancer liver parachyma and background liver parachyma were measured on DWI with b value of 600 s/mm2.The Kruskal-Wallis H with Bonferroni test was used to test the differences between the measured values of the four tissues,and the receiver operating characteristic curve(ROC)analysis was used to evaluate the diagnostic efficacy of the measured values with statistical difference.Results:(1)Comparison of the differences in average ADC and eADC of four tissues:the average ADC of cancer tissue was significantly lower and the average eADC of cancer tissue was significantly higher than that of para-cancer tissue,far-cancer liver parachyma,and background liver parachyma(adjusted P-values<0.008),but there was no significant difference in average ADC and eADC among para-cancer tissue,far-cancer parachyma and background liverparachyma(adjusted P-values>0.008).(2)The efficiency of average ADC and eADC in distinguishing the four tissues:For differentiating cancer tissue from para-cancer tissue,far-cancer parachyma and background liver parachyma,the areas under the ROC curve of the average ADC value were 0.735,0.780 and 0.732,respectively,and the areas under the ROC curve of the average eADC value were 0.739,0.794 and 0.742,respectively.Conclusion:The average ADC and eADC values can help to distinguish HCC from para-cancer tissue,far-cancer parachyma and background liver parachyma,but can not distinguish para-cancer tissue,far-cancer parachyma and background liver parachyma.Objective:To investigate the differences in apparent diffusion coefficient(ADC)and exponential apparent diffusion coefficient(eADC)obtained from different b values of diffusion weighted imaging(DWI)among hepatocellular carcinoma(HCC),proximal para-carcinoma tissue,distal para-carcinoma tissue,far-cancer liver parachyma and background liver parachyma on ultra high field 3.0T MRI.Methods:Sixty-eight consecutive patients with HCC confirmed by surgical biopsy in our hospital were enrolled from January 2018 to October 2021.The average ADC and eADC of HCC,para-carcinoma tissue(The tissue within 1.0 cm from the edge of the tumor was defined as proximal para-carcinoma tissue,1.0 cm～1.5 cm from the edge of the tumor wasdefined as distal para-carcinoma tissue),far-cancer liver parachyma and background liver parachyma were measured on DWI with different b values(b=50,100,200,400,600,1000 s/mm2)by ultra high field 3.0 T MRI.The differences in average ADC and eADC among the five tissues were compared by the Kruskal-Wallis H test with Bonferroni test,and the receiver operating characteristic curve(ROC)analysis was performed to evaluate the differential diagnosis performance.Results:(1)Comparison of average ADC and eADC of five tissues measured on multiple b value DWI images:There were significant differences in average ADC and eADC measured on different b values(b=50,100,400,600,1000 s/mm2)between HCC,proximal para-carcinoma tissue,distal para-carcinoma tissue,far-cancer liver parachyma and background liver parachyma(adjusted P-values<0.005).There weresignificant differences in average ADC and eADC when b=50 s/mm2 between proximal para-carcinoma tissue and far-cancer liver parachyma,proximal para-carcinoma tissue and background liver parachyma(adjusted P-values<0.005),there was no significant difference in other b values(b=100,400,600,1000 s/mm2),(adjusted P-values>0.005).There were no significant differences in average ADC and eADC of distal para-carcinoma tissue,far-cancer liver parachyma and background liver parachyma(adjusted P-values>0.005).(2)The efficiency of average ADC and eADC in distinguishing the five tissues:the ROC curve analysis showed that thediagnostic efficiency was the best when b=50 s/mm2 to distinguish HCC from proximal para-carcinoma tissue,distal para-carcinoma tissue,far-cancer liver parachyma and background liver parachyma with the areas under the ROC curve(AUC)of ADC were 0.792,0.819,0.84 and 0.848,respectively;the AUCs of eADC were 0.803,0.829,0.851 and 0.862 respectively.The AUCs of average ADC differentiating proximal para-carcinoma tissue from far-cancer liver parachyma,and from background liver parachyma were 0.568 and 0.571,respectively.The AUCs of eADC were 0.564 and 0.578,respectively when b=50 s/mm2.Conclusion:The average ADC and eADC measured on multiple b values DWI images are helpful to distinguish HCC from proximal para-carcinoma tissue,distal para-carcinoma tissue,far-cancer liver parachyma and background liver parachyma.Distal para-carcinoma tissue,far-cancer liver parachyma and background liver parachyma cannot be distinguished from each other.When b=50 s/mm2,the average ADC and eADC are helpful to distinguish proximal para-carcinoma tissue from far-cancer liver parachyma,and from background liver parachyma.