[Study of diffusion weighted imaging in combination with conventional MRI signs for inflammation activity of chronic hepatitis B].

To study the correlation between ADC values of diffusion weighted imaging (DWI) and the pathological grading in inflammation activity of chronic hepatitis B, and combined with conventional MRI features to predict the diagnosis effectiveness. A total of 142 cases of patients with chronic hepatitis B were selected as inflammatory group in 302 Hospital of PLA from January 2014 to December 2015, while 20 cases of healthy subjects without history of liver disease were chosen as control group.All patients underwent MR plain scan and dynamic contrast enhancement and DWI examinations (b=0, 800 s/mm(2)) for liver, and were performed liver biopsy within two days.According to the degree of inflammation activity (G), the inflammation group was divided into G1, G2 and G3-4 level.The apparent diffusion coefficient (ADC) value, and the MRI features of each group were analyzed. The ADC values showed statistical difference (=8.392, <0.01) within inflammation group of chronic hepatitis B from different pathologic grading, and there was significant negative correlation between ADC values and liver inflammation activity grading (=-0.613, <0.01). The ADC value of inflammation group and control group was (1.31±0.16), (1.12±0.15)×10(-3) mm(2)/s, the difference was statistically significant (<0.05). The ADC value of G1, G2 and G3-4 level was (1.22±0.12), (1.05±0.12), (0.98±0.10)×10(-3) mm(2)/s respectively, and there was statistical difference (<0.05) between G1 and G2, G1 and G3-4. The receiver operating characteristic (ROC) curve in diagnosis of equal and above G2 level showed the area under the curve (AUC) was 0.880, the sensitivity and the specificity was 82.4% and 76.8% respectively, the diagnostic cut-off value was 1.09×10(-3) mm(2)/s.Besides, the detection rate of portal around its orbit and gallbladder wall edema in inflammation group had statistical difference (<0.05), and there was no statistical difference in the detection rate of abnormal liver arterial enhancement, hilus lymph node increases and ascites in inflammation group(>0.05). The ROC in diagnosis of equal and above G2 level by ADC values combined with the MRI characteristic signs showed AUC was 0.938, the sensitivity and the specificity was 88.4% and 88.9% respectively. ADC values can predict the inflammation activity of chronic hepatitis B with quantitatively and non-invasively.Combining with characteristic MRI signs, ADC values can improve the diagnosis efficiency.