Abstract: Objective The aim of this study was to investigate the dynamic contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) in the diagnosis of microvascular invasion (MVI) in patients with primary liver cancer (PLC). Methods 50 patients with PLC were admitted to our hospital between January 2020 and January 2023, and all underwent plain and dynamic contrast-enhanced CT and MRI scan before operation. The blurry tumor margins, such as locally convex nodules, locally incomplete capsule, multi-nodule fusion, intra-tumor crescent sign, two-trait predictor of venous invasion (TTPVI), portal vein tumor thrombosis (PVTT) and apparent diffusion coefficient (ADC) were recorded. All patients underwent hepatectomy and the post-operational examination was conducted for the diagnosis of MVI. Results The postoperative histopathological examination found that among the 50 patients with PLC, there were 32 patients with hepatocellular carcinoma (HCC) and 18 patients with cholangiocellular carcinoma, with MVI positive in 29 cases and without MVI in 21 cases; the CT scan found that the proportions of the blurry tumor margins, locally convex nodules, locally incomplete capsule, multi-nodule fusion, intra-tumor crescent sign, TTPVI and PVTT among patients with MVI were 82.8%, 17.2%, 31.0%, 17.2%, 13.8%, 65.5% and 17.2%, all significantly higher than 14.3%, 4.8%, 4.8%, 4.8%, 0.0%, 9.5% and 0.0% (P<0.05) in patients without MVI; the MRI found that the proportions of the blurry tumor margins, locally convex nodules, locally incomplete capsule, multi-nodule fusion, intra-tumor crescent sign, TTPVI and PVTT among patients with MVI were 89.7%, 24.1%, 37.9%, 27.6%, 13.8%, 72.4% and 24.1%, all significantly higher than 23.8%, 9.5%, 9.5%, 9.5%, 0.0%, 14.3% and 0.0% (P<0.05) in patients without MVI; the Logistic regression analysis showed that the blurry tumor margins, TTPVI and PVTT were the independent risk factors for the existence of MVI in patients with PLC (P<0.05). Conclusion The special signs of dynamic contrast-enhanced CT and MRI scan could hint the existence of MVI, which might help the gastroenterologists make an appropriate management strategy.

Key words: Hepatoma, Microvascular invasion, CT, MRI, Dynamic contrast-enhanced scan, Diagnosis