Imaging findings of hepatocellular carcinoma with portal vein tumor thrombosis secondary to hepatic portal vein collateral circulation: a cross-sectional study - Shi, Bo; Bian, Chen; Li, Zhigang; Chen, Jun; Yang, Dongqiang; Li, Yazhou; Hao, Xiaoguang; Ping, Yong (Journal of Gastrointestinal Oncology, 2023)