The value of hepatobiliary phase in EOB-MRI in predicting hypervascularization outcome of non-hypervascular hypointense lesions in high-risk patients for hepatocellular carcinoma

Purpose: To estimate the role of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced MRI (EOB-MRI) in predicting hypervascularization outcome of non-hypervascular hypointense hepatic lesions in high-risk patients for hepatocellular carcinoma (HCC).

Methods: Under the premise of non-hyperenhance in arterial phase (AP) and hypointensity in hepatobiliary phase (HBP) of EOB-MRI, 29 fresh lesions from 22 patients with chronic viral hepatitis (median (range) age: 69(57-82) years) were prospectively enrolled. During continuously followed-up by EOB-MRI, lesional vascularity in AP, the signal intensity (SI) ratios of lesions-to-parenchyma in HBP images (post-contrast ratio) and adjusted enhancement with reference of unenhanced images (EOB enhancement ratio) were examined.

Results: After 644 (220-2912) days of follow-up, 20 lesions changed into hyperenhancement in AP of EOB-MRI (hypervascularized group), while nine remained non-hyperenhanced (maintained non-hypervascular group). There is no statistical difference of post-contrast ratio at the initial detection. The post-contrast ratios in hypervascularized group were different between each follow-up time point when followed-up ≥ three (P < 0.01) and four (P < 0.05) times, and exposed a linear downward trend with time. Between the hypervascularized and maintained non-hypervascular groups, there were significant differences in the post-contrast ratio at endpoint for three-times' follow-up (P < 0.001); and at the second (P = 0.037), third follow-up time points (P = 0.005), endpoint (P = 0.005) for four-times' follow-up. EOB enhancement ratio showed inter-group difference only at endpoint for three-times' follow-up (P = 0.008).

Conclusion: For non-hypervascular, HBP hypointense hepatic lesions, decreasing trend of SI in HBP may early predict unfavorable hypervascularized outcome.