Background and Aims: Pancreatectomy is a complex procedure with a high risk of accidental intraoperative bleeding. Accurate preoperative assessment of the origin and running course of the peripancreatic vessels is helpful to reduce the risk of intraoperative bleeding. There is still lacking systematic study of the anatomy of peripancreatic vessels in Chinese population. The purpose of this study is to ascertain the anatomical characteristics of the dorsal pancreatic artery (DPA) and the inferior pancreaticoduodenal artery (IPDA) in Chinese, and further to explore the best post-processing method of CT images.  
Methods: The imaging data of patients who underwent abdominal enhanced CT examination from December 2016 to June 2017 were collected for multiplanar reconstruction (MPR), maximum intensity projection (MIP),  volume rendering (VR) and so on. The data of the DPA and IPDA were observed by two experienced radiologists who are familiar with the anatomy of pancreatic vessels, and the observed variables included the number of branches of the DPA and IPDA, the location of the origin, and the distance from the root of superior vessels. The detection rates of different CT post-processing techniques for corresponding vessels were also compared. 
Results: During the period, a total of 762 patients underwent abdominal enhanced CT examination. According to the inclusion and exclusion criteria, 211 patients were enrolled, including 98 males and 113 females, with age from 16 to 92 years, and BMI from 17.5 to 35.2 kg/m2. In the whole group of patients, the detection rates of the DPA and IPDA were 95.3% and 96.2%, respectively. The DPA arising from the celiac trunk (CA) accounted for 58.7%. Among them, 49.1% (58/118) originated from the splenic artery, and the average distance from the origin to the root was 4.6 (2–10) mm; 39.8% (47/118) were derived from the hepatic artery, and the average distance from the origin to the root was 6.4 (2–10) mm; in addition, 6.8% (8/118) and 4.2% (5/118) of the DPA came from the bifurcation of the CA and CA itself, respectively. The DPA arising from the superior mesenteric artery (SMA) accounted for 41.3%, and their origin sites were mostly located at the 9–12 points of the SMA (94.0%, 78/83), and the average distance from the root of SMA was 26 (18–45) mm. There were 171 cases (84.2%), 29 cases (14.3%) and 3 cases (1.5%) had one, two or three IPDA, respectively. According to the relationship between IPDA and the first jejunal artery (FJA), they were classified as common trunk or separate independent origins with the FJA. About 60.1% (122/203) of IPDA and the FJA originated from the same trunk. The root of IPDA usually located at 4–7 points of the SMA (75.4%, 92/122). The average distance from the root of SMA was 42 (18–54) mm. About 39.9% of the IPDA originated from the SMA directly, which was usually located at 6–9 points of the SMA, with an average distance of 40 (18–52) mm from the root of the SMA. A total of 10.4% of the IPDA (22/211) had the common trunk with the DPA. The display rates of 1-mm reconstruction, MIP and VR for DPA were 93.8% (198/211), 95.3% (201/211) and 94.3% (199/211) respectively, which were significantly better than those of 3 mm (81.5%, 172 / 211) or 5 mm (68.7%, 145/211) reconstruction (all P<0.01), and for IPDA were 94.8% (200/211), 96.2% (203/211) and 94.8% (200/211) respectively, which were also significantly better than those of 3 mm (78.2%, 165/211) or 5 mm (67.3%, 142 / 211) reconstruction (all P<0.01).
Conclusion: The origins and running courses of the DPA and IPDA are complex. Preoperative 1 mm CT reconstruction can clarify the anatomical characteristics of the DPA and IPDA, which is helpful for the dissection of related vessels and reducing the risk of accidental injury.