Presence of microvascular invasion can be estimated preoperatively, by some clinical imaging features such as patient characteristics, serum biomarkers and radiological features. Contrast-enhanced ultrasonography (CEUS) and contrast-enhanced computed tomography (CECT) are routine preoperative conventional examinations for hepatocellular carcinoma (HCC) patients in China. Combining features of CEUS, CECT and clinical factors may improve preoperative MVI assessment. The purpose of this study is to construct a nomogram for preoperative MVI risk estimation with these possible factors.

Inclusion Criteria:

• Asian patients aged 18～80 years old;
• With no preoperative anti-cancer treatment;
• Scheduled for radical liver resection;
• With both CEUS and CECT performed in 4 weeks before surgery;
• Postoperative histologically confirmed HCC;
• With sufficient surgical specimen for MVI detection (surgical margin ≥1cm);

Exclusion Criteria:

• Recurrent HCC or combined hepatocellular-cholangiocarcinoma;
• With extra-hepatic metastasis or macrovascular invasion;
• With incomplete clinical and imaging data;
• Non-radical resection;

Between April 2017 and April 2019，all consecutive patients who will undergo curative resection (R0 resection) at the First Affiliated Hospital of Sun Yat-Sen University in Guangzhou, China, for HCC based on the modified WHO classification of tumors of the digestive system, are considered for inclusion. By the eligibility criteria stated below, MVI presentative rate is 30-42% in chinese HCC population as reported, and an estimated 400 patients will be needed for this study.