Objective To assess the value of multi-slice computed tomography angiography (MSCTA) in the preoperative detection of aberrant hepatic arteries in patients scheduled to undergo pancreaticoduodenectomy.Methods Patients with pancreatic and peri-ampullary tumors were preoperatively studied using contrast-enhanced abdominal CT angiography (CTA).The results on hepatic arterial anatomy were compared with those obtained from digital subtraction angiography (DSA) and on surgical findings.Results Eighty-one patients were included into this study.DSA was carried out in 29 patients to evaluate tumor resectability,and 66 patients received surgery.Anomalous hepatic arteries were detected in 17 (21％) patients on CTA.Thirteen (16.0％) patients had a single arterial variant,and 4 (4.9％) patients had two arterial variants.One patient each was seen in the Michels type Ⅳ,Ⅶ,and Ⅷ respectively,while 2 patients each were seen in the Michels type Ⅲ and Ⅴ respectively.Five patients were diagnosed as the Michels type Ⅵ,and four as the Michels type Ⅸ.One patient demonstrated a rare variant which was not included into the Michels classification.MSCTA had an accuracy of 100％,a sensitivity of 100％,and a specificity of 100％.Regarding the traceability scores of hepatic arterial segment,there were no statistically significant differences between MSCTA and DSA.Conclusions MSCTA is an effective imaging tool to assess arterial anatomical variation around the pancreatic head.It is non-invasive,and it provides valuable information on the peri-pancre atic vascular anatomy before pancreaticoduodenectomy.