Data of 151 cases of cHCC-ICC from patients who had received dynamic enhanced CT scanning in three hospitals from September 2006 to August 2022 were retrospectively collected.

Inclusion criteria: (1) Age 18\(-\)80 years old; (2) CT indicates liver tumor \(\ge\) 1 cm; (3) Completed the surgical resection of liver tumor, which had been confirmed as cHCC-ICC by postoperative pathology.

Exclusion criteria: (1) Age 0 18 years old or over 80 years old; (2) Poor quality of CT scan image or the phase was incomplete; (3) Those who did not receive resection of the liver tumor but only underwent puncture; (4) Incomplete laboratory test data; (5) Those who had received other treatments before the operation.

Data of levels of alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), carbohydrate antigen 199 (CA-199), alanine aminotransferase (ALT), aspartate aminotransferase (AST), PLT, total bilirubin (TBIL), and γ-glutamyl transpeptidase (GGT), as well as quantitative analysis results of hepatitis B virus were acquired.

This was a retrospective study approved by the hospital ethics committee. All images and clinical data were acquired from the PACS system; thus, informed consent was exempted.

Siemens 64 slice CT scanner, scanning parameters: tube voltage 120 kV, tube current automatic mA regulation technology, layer thickness 5 mm; Reconstruction parameters: pitch 1, reconstruction layer thickness 1 mm. The window width was 250 Hu, and the window level was 50 Hu. The tracking monitoring started 10 s after the contrast medium was injected. When the CT value of the monitoring layer reached the trigger threshold, the early arterial phase was acquired at 6 s delay and the late arterial phase was obtained at 8 s delay. The portal vein phase was captured 60 s after injection of the intravenous contrast medium, and the delayed image was obtained 120 s after injecting the contrast medium. The images were transmitted to PACS in DICOM format.

Equipment 2: GE 64 slice CT scanner (Biograph m CT). Parameters: layer thickness 6 mm, voltage 120 kV, matrix 512 × 512. The hepatic artery phase was 20 ~ 30 s, the portal vein phase was 50 ~ 60 s, the delay phase was 180 ~ 200 s, the window width was 250 ~ 300 HU, and the window level was 40 ~ 80 HU.

Two radiologists who have been engaged in abdominal imaging diagnosis for more than 15 years analyzed the signs of all cHCC-ICC cases in the PACS system, including whether there was atrophy of the liver lobe, depression of the liver capsule, dilation of the surrounding bile duct, size, edge, shape of the focus, the presence or absence of capsule and lipid inside, CT density, tumor thrombus in the portal vein, enhancement methods in each phase of enhanced scanning, whether there was a peritumoral enhancement in the arterial phase. The evaluators had no prior knowledge of patients’ clinical data. In case of doubt, consultation would be initiated to reach an agreement.

Microvascular invasion (MVI) refers to the microscopic observation of cancer cell nests in the vascular lumen lined with endothelial cells, mainly portal vein or hepatic vein branches (including intrathecal vessels). Pathological grading method: M0: no MVI was found; M1 (low-risk group): ≤ 5 MVI, and it occurred in the liver tissue near the cancer; M2 (high-risk group): >5 MVI, or MVI occurring in the liver tissue near the distant cancer. After reading the images, it was found that there were only a few M2 cases in this group, and thus M1 and M2 were combined into the MVI-positive group.

An experienced pathologist (who has 16-year experience in the pathological diagnosis of liver cancer) was asked to review the sections of all cases and evaluate whether cirrhosis was present. The relationship between CT findings and histopathology was jointly determined by radiologists and pathologists.

Specimens were fixed with 4% neutral buffered formaldehyde and embedded in conventional paraffin µM serial sections, routine HE staining and immunohistochemical staining. DAB (3,3’-diaminobenzidine) was used in immunohistochemical (IHC) staining. Hematoxylin was applied for re-staining, prior to which the slides were hydrated. Blue flower was dehydrated and sealed. Factor VIII related antigen (F - VIII Ag) was used to display the microvessels in the lesions.