Optimal Segment Selection on Gadoxetic Acid-Enhanced MRI to Improve Diagnostic Accuracy in the Histological Grading of Liver Inflammation and Fibrosis in Patients with Chronic Hepatitis B

<b>Background/Objectives:</b> To investigate the role of hepatobiliary phase (HBP) signal intensity (SI) on Gadoxetic acid (GA)-enhanced liver magnetic resonance imaging (MRI) in improving the diagnostic accuracy of the histological grade of fibrosis in patients with chronic hepatitis B (CHB). <b>Methods:</b> This retrospective study enrolled patients with CHB who underwent biopsies from the highest and lowest intensity areas identified on HBP images obtained from GA-enhanced MRI. The patients were divided into two groups based on segmental SIs: Group 1 (maximum SI) and Group 2 (minimum SI). An ultrasound-guided tru-cut biopsy was performed in these two segments. Forty patients undergoing histopathological examination were included in the study. Group comparisons were examined using Chi-square and independent-sample <i>t</i>-tests, and receiver operating characteristic curve analysis (ROC) was performed to determine the cutoff values of the SI for modified histologic activity index (mHAI) and fibrosis grading. <b>Results:</b> There were no histopathological differences between the groups (<i>p</i> > 0.05), but significant inflammation and fibrosis were observed in hepatic segments with an SI value of <617 (<i>p</i> < 0.001). The ROC results showed that the predictive cutoff value of SI for mHAI and fibrosis grading were 606 (AUC: 0.83, 95% CI 0.737-0.921, <i>p</i> < 0.001) and 599 (AUC: 0.85, 95% CI 0.766-0.935, <i>p</i> < 0.001), respectively. <b>Conclusions:</b> In patients with CHB, performing a biopsy from the liver segment with the lowest SI on GA-enhanced MRI increases the diagnostic accuracy for assessing the histological severity of hepatic inflammation and fibrosis.