Figure 1 Images to illustrate construction of LFSS. Case 1: A 24-year-old woman with a large right lobe HCC. Preoperative axial multiphasic CT images (A–C) showing typical radiological features of HCC, normal liver morphology, and regular margin. (A) unenhanced CT phase; (B) arterial phase; (C) portal venous phase. Intraoperative photography (D) showed normal liver morphology, absence of regenerative nodules, and ruddy liver parenchyma. According to our LFSS criteria, preoperative radiological evaluation score: 0 (normal morphology), intraoperative observation: 0 (no liver regenerated nodules), liver gross appearance color: ruddy (0), thus total score of LFSS was 0 (None). (E) Histological evaluation of paracancerous parenchyma showed G1 and S1 (HE, 100×). Case 2: A 37-year-old woman with spontaneous rupture of HCC in segment IV. Preoperative axial multiphasic CT images (A–C) showing hypertrophy of the lateral segments of the left liver lobe and regular hepatic margins. (A) unenhanced phase; (B) arterial phase; (C) portal venous phase. Notes: Filling defect caused by tumoral thrombosis was noted in the sagittal part of left portal vein. Intraoperative photography (D) showed multiple micro-regenerative nodules and red liver parenchyma. According to our LFSS criteria, preoperative radiological evaluation score: 1 (morphological change), intraoperative observation: 1 (multiple regenerative micronodules), liver gross appearance color: red (0), thus total score of LFSS was 2 (Mild). (E) Histologic evaluation of paracancerous parenchyma showed G3 and S2 (HE, 100×). Case 3: A 47-year-old man with HCC in the segment VIII. Preoperative axial multiphasic CT images (a-c) were obtained showing liver morphologic change (atrophy of the posterior segments of the right liver lobe) and regular margin. (A) unenhanced phase; (B) arterial phase; (C) portal venous phase. Notes: Anterior branch of right portal vein and distal branch of middle hepatic vein invaded by tumor. Intraoperative photography (D) showed multiple regenerative micronodules and greyish-red liver parenchyma. According to our LFSS criteria, preoperative radiological evaluation score: 1 (morphological change), intraoperative observation: 1 (multiple regenerative micronodules), liver gross appearance color: greyish-red (1), thus total score of LFSS was 3 (Moderate). (E) Histologic evaluation of paracancerous parenchyma showed G3 and S3 (HE, 100×). Case 4: A 57-year-old man with HCC in segment VIII. Preoperative axial multiphasic MR images (A–C) showing liver morphologic changes (atrophy of the posterior segments of the right lobe and medial segments of the left lobe, hypertrophy of the lateral segments of the left lobe) and irregular hepatic margins. (A) precontrast phase; (B) hepatic arterial phase. Notes: Enhancement of portal vein branches but not of hepatic vein branches in hepatic arterial phase; (C) portal venous phase. Notes: Middle and right hepatic veins were compressed by tumor. Intraoperative photography (D) showed multiple regenerative nodules and red liver parenchyma. According to our LFSS criteria, preoperative radiological evaluation score: 1 (morphologic change), intraoperative observation: 2 (multiple regenerative macronodules), liver gross appearance color: red (0), thus total score of LFSS was 3 (Moderate). (E) Histologic evaluation of paracancerous parenchyma showed G3 and S4 (HE, 100×). Case 5: A 61-year-old man with HCC in segment VII. Preoperative axial multiphasic CT images (A–C) showing pronounced liver morphologic changes and irregular margins. (A) unenhanced phase; (B) arterial phase; (C) portal venous phase image; (D) coronal view shows signs of clinically significant PH (engorged and tortuous paraesophageal varices and splenomegaly). Intraoperative photography (E) showed uneven distribution of multiple regenerative micro- and macronodules and greyish-red liver parenchyma. According to our LFSS criteria, preoperative radiological evaluation score: 2 (confirmed liver cirrhosis and/or imaging features of PH), intraoperative observation: 2 (multiple macro-regenerative nodules), liver gross appearance color: 1 (greyish-red), thus total LFSS score was 5 (Severe). (F) Histologic evaluation of paracancerous parenchyma showed G4 and S4 (HE, 100×). Case 6: A 48-year-old man with HCC of the right lobe. Preoperative axial multiphasic CT images (A–C) showing pronounced liver morphologic changes, ascites and splenomegaly. (A) unenhanced phase; (B) arterial phase; (C) portal venous phase. Notes: Neither the right hepatic nor the right portal veins were visualized; (D) coronal image shows compression of the retrohepatic inferior vena cava by tumor and splenomegaly. Notes: This patient received a preoperative diagnosis of intrahepatic cholangiocarcinoma with concomitant PH and cirrhosis. However, postoperative pathology confirmed a diagnosis of HCC. Intraoperative photography (E) showed morphologic changes, no regenerative nodules, and ruddy liver parenchyma. According to our LFSS criteria, preoperative radiological evaluation score: 2 (confirmed cirrhosis and/or imaging features of PH), intraoperative observation: 0 (no regenerative nodules), liver gross appearance color: red (0), thus total LFSS score was 2, (Moderate, in contrast to preoperative assessment as Severe with indicator of PH). (F) Histologic evaluation of paracancerous parenchyma showed G1 and S0 (HE, 100×).