Abstract: Objective To analyze the correlation between magnetic resonance (MR) signal characteristics and microvascular invasion (MVI) in small hepatocellular carcinoma (sHCC).Methods Patients diagnosed with sHCC who received dynamic contrast-enhanced MR scan within 1 month before operation from December 2010 to January 2019 in our hospital were enrolled. And all the cases were divided into MVI group and non-MVI group according to pathological diagnosis, alpha-fetoprotein (AFP) positive group and negative group according to AFP level. Preoperative MR, T1WI, T2WI and DWI sequence, as well as signal values of arterial, portal and delayed phase of dynamic enhanced scanning were recorded. The signal value ratio of the lesions to the adjacent liver in arterial, portal and delayed phase was calculated. Results For 33 patients enrolled in the study, there were 22 cases with MVI, 11 cases with non-MVI, 17 cases with positive AFP and 16 cases with negative AFP. In patients with positive AFP, there was significant difference in the signal characteristics of arterial and delayed phase between MVI group and non-MVI group (P<0.05), but no significant difference in T1WI, T2WI and DWI sequence. However, in patients with negative AFP, there was no significant difference in T1WI, T2WI, DWI sequence and dynamic contrast-enhanced scan between groups.Conclusion MR signal features of dynamic contrast-enhanced scan could be used to predict the presence of MVI in sHCC.

Key words: Small hepatocellular carcinoma, Microvascular invasion, MR