Quantitative Analysis of Diffusion Tensor Imaging in Chronic Hepatitis in Rats

Abstract

<jats:title>Abstract</jats:title> <jats:p>Background Diffusion tensor imaging (DTI) is mainly used for detecting white matter fiber in the brain. From this, DTI has been applied to assess fiber in liver disorders by prior studies. But non-sufficient data has been obtained if DTI could be used for exactly staging chronic hepatitis. This study is to assess the value of DTI for staging of liver fibrosis (F), necroinflammatory activity (A), and steatosis (S) of chronic hepatitis in rats. Methods Seventy male Sprague-Dawley rats were divided into control group(n = 10) and experimental group(n = 60). The rat models of chronic hepatitis were established by abdominal subcutaneous injections of 40% CCl<jats:sub>4</jats:sub>. All rats underwent 3.0T MRI. ROIs were placed on DTI to estimate MR parameters (rADC value and FA value). Histopathology was the reference standard. Multiple linear regression was used to analyze the association between MR parameters and pathology. The differences in rADC value and FA value among pathological stages were evaluated by MANOVA or ANOVA. LSD was used to test the differences between each two groups. ROC analysis was performed. Results The numbers of each pathology were as follows: F0(n = 15), F1(n = 11), F2(n = 6), F3(n = 9), F4(n = 6); A0(n = 8), A1(n = 16), A2(n = 16), A3(n = 7); S0(n = 10), S1(n = 7), S2(n = 3), S3(n = 11), S4(n = 16). The rADC value had a negative correlation with liver fibrosis (<jats:italic>r</jats:italic>=-0.392, <jats:italic>P</jats:italic> = 0.008) and inflammation (<jats:italic>r</jats:italic>=-0.359, <jats:italic>P</jats:italic> = 0.015). FA value had a positive correlation with fibrosis (<jats:italic>r</jats:italic> = 0.409, <jats:italic>P</jats:italic> = 0.005). Significant differences were found in FA value between F4 and F0 ~ F3 (<jats:italic>P</jats:italic> = 0.03), while no significant differences among F0 ~ F3 were found (<jats:italic>P</jats:italic> &gt; 0.05). AUC of FA value in differentiating F4 from F0 ~ F3 was 0.909(<jats:italic>p</jats:italic> &lt; 0.001) with 83.3% Sensitivity, 85.4% specificity when the FA value was at the cut-off of 588.089(× 10<jats:sup>− 6</jats:sup>mm<jats:sup>2</jats:sup>/s). Conclusion FA value for DTI can distinguish early cirrhosis from normal, mild and moderate liver fibrosis.</jats:p>