Abdominal cross-sectional imaging of the associating liver partition and portal vein ligation for staged hepatectomy procedure

Table 1 Institutional multiphasic multidetector computed tomography protocol for evaluating associating liver partition and portal vein ligation for staged hepatectomy patients before and after surgery (LightSpeed HD, General Electrics, Milwaukee, United States)

Scan phase (timing from contrast injection)	Scal lenght	Scanning parameters	Rationale in the preoperative phase	Rationale in the postoperative phases
Unenhanced	Upper abdomen	KVp 120 mA modulated between 200-450 Tube rotation 0.6 s Pitch 0.984 Noise index 16.10 Collimation 1.25 mm (0.625 for the angiographic phase) Image reconstruction thickness 1.25 mm	Identifying potential confounders in image interpretation (e.g., lesion’s or vascular calcifications). Measuring baseline attenuation of target lesions (e.g., fat-containing HCC) or in diffuse liver disease (e.g., steatosis)	Identifying potential confounders in image interpretation (e.g., surgical clips). Measuring the attenuation of intra-abdominal collections (biloma vs hematoma)
			This phase is not required if recent prior imaging is available.	This phase in not mandatory in repeated follow-up examinations
Angiographic phase (20)	Upper abdomen		Assessing the patency and anatomic variants of the hepatic artery and its branches, both on source images and MIP reconstructions	Assessing the sources of suspicious active postoperative bleeding
Delayed arterial (35-40 s)	Upper abdomen		Assessing hypervascular focal liver lesions (malignant and benign ones)	Assessing the patency of the hepatic artery and its branches. Identifying the recurrence of hypervascular tumors in the delayed post-operative period
Venous (70 s)	Whole abdomen		Assessing lesions’ enhancement pattern for the purpose of identification/characterization. Assessing the patency and anatomic variants of the portal trunk and intrahepatic branches, both on source images and MIP reconstructions. Identifying additional abdominal findings potentially contraindicating ALPSS. Assessing for signs of chronic liver disease (including splenomegaly, venous collaterals and ascites)	Assessing the portal status (absence of flow in the ligated portal branch and patency of the FLR branch). Assessing successful tumor cleaning up in the FLR before surgical stage 2. Ruling out thrombosis of the portal braches, hepatic veins and inferior vena cava. Identifying tumor relapse
Delayed (3-5 min)	Upper or whole abdomen, depending on findings on previous scans		Assessing lesions’ enhancement pattern for the purpose of identification/characterization. Identifying additional findings potentially contraindicating ALPSS (e.g., peritoneal carcinosis). This phase is not mandatory	Assessing venous bleeding. This phase in not mandatory

MIP: Maximum intensity projection; FLR: Future liver remnant; ALPPS: Associating liver partition and portal vein ligation for staged hepatectomy; HCC: Hepatocellular carcinoma.