The purpose of this study was to evaluate the diagnostic ability of the expanded gallbladder fossa and right posterior hepatic notch signs for hepatic
fibrosis determined by double contrast-enhanced MRI. For patients with chronic viral
hepatitis B (n = 96) or
hepatitis C (n = 13) who underwent gadopentate dimeglumine-enhanced dynamic MRI followed by
ferucarbotran-enhanced gradient-echo imaging, the degree of parenchymal
fibrosis was categorised into three groups based on the extent of reticulation and nodularity: (1) pre-cirrhotic or minimal
fibrosis; (2) mild to moderate
fibrosis; (3) advanced
cirrhosis. Each group was evaluated for the presence of a sharp notch in the posterior-medial surface of the right lobe of the liver and expanded gallbladder fossa. The expanded gallbladder fossa sign gradually increased with an increasing degree of
fibrosis (Group 1, 50%; Group 2, 61%; Group 3, 78%), and there was no significant difference (p>0.5) between
hepatitis B (67%) and
C (73%). In the case of the right posterior hepatic notch sign, only 6% of Group 1 and Group 2 patients were positive; 27% of
hepatitis B patients and 90% of
hepatitis C patients in Group 3 exhibited the sign (p<0.05). Owing to its low prevalence, even in advanced
cirrhosis, the right posterior hepatic notch sign is of little value in the diagnosis of
cirrhosis due to
chronic hepatitis B virus infection, whereas an expanded gallbladder fossa could be used as a non-specific
indicator of early
fibrosis before the gross appearance of advanced hepatic
fibrosis.