Optimal timing of contrast-enhanced computed tomography in an evaluation of severe acute pancreatitis-associated complications.

Dynamic contrast-enhanced computed tomography (CECT) has been used previously to evaluate severe acute pancreatitis (SAP)-associated complications. However, optimal time points of CECT have not yet been established. The present study aimed to determine optimal timings for CECT to be undertaken for patients with SAP. The results of CECT from 309 patients with SAP, who were classified into either infected or non-infected SAP groups, were retrospectively analyzed. The severity and alterations in the periods within 72 h to >4 weeks of SAP onset were also assessed. In the analysis of the disease severity and changes, acute peripancreatic fluid collection was detected, where the number of areas increased within 1 week of SAP onset but decreased within 4 weeks and longer. However, no significant differences were observed between the infected and non-infected groups. The acute necrotic collection (ANC) areas were ≤30% of the area of the pancreas, with significantly more ANC areas and pancreatic necrosis in the infected SAP group compared with the non-infected SAP group at a time interval of >4 weeks. The exudation of pleural effusion (PE) was elevated within 1 week, but decreased within 2 weeks and longer. The difference in the alteration of the exudation of PE was not statistically different between the two groups. In conclusion, the results suggest that the period between 72 h and 1 week of SAP onset is optimal timing of CECT to assess SAP-associated complications, particularly for infected SAP patients.