Distinct vascular patterns (ECTC or Non-ECTC) of tumors plays an important role in tumor migration, metastasis and drug resistant in hepatocellular carcinoma (HCC). However, there is no non-invasive method to predict vascular pattern in clinical. In the present study, we prospectively assess CT perfusion parameters for evaluation of the vascular pattern in HCC.

Inclusion Criteria:

1. age over than 18 years old
2. tumor size of less than 5 cm
3. Child-Pugh A class liver function
4. an Eastern Cooperative Oncology Group performance status of 0
5. no previous treatment for HCC
6. pathological diagnosis of hepatocellular carcinoma
7. adequate organ function (white blood cell count ≥3.0 × 109/L, absolute neutrophil count ≥1.5 × 109/L, platelet count ≥75 × 109/L, aspartate transaminase and alanine transaminase≤5 × upper limit of the normal, creatinine clearance rate of ≤1.5 × upper limit of the normal, and left ventricular ejection ≥45%)

Exclusion Criteria:

1. Patients who received antitumor therapy before recurrence, including radiotherapy, transarterial chemoembolization, tyrosine kinase inhibitor, and immune checkpoint inhibitor
2. a known medical history of HIV infection
3. pregnancy or breastfeeding
4. portal vein tumor thrombosis or hepatic vein thrombosis detected by any routine imaging modality, including ultrasonography, dynamic contrast CT and MRI
5. any evidence of tumor metastasis or prior recurrence
6. hepatic decompensation

HCC patients with tumor size of less than 5 cm who would receive liver resection.