CT Characteristics of Acute Pancreatitis with Preexisting Fatty Liver and Its Impact on Pancreatitis Severity and Persistent Systemic Inflammatory Response Syndrome

PURPOSE: To study the CT characteristics of acute pancreatitis (AP) associated with preexisting fatty liver (FL) and the impact of preexisting FL on the severity of AP and persistent systemic inflammatory response syndrome (SIRS). PATIENTS AND METHODS: A total of 189 patients with AP were divided into AP with and without preexisting FL. The CT features, clinical characteristics, severity of AP, and presence of persistent SIRS between the two groups were compared. Univariate and multivariate analyses were performed to determine the risk factors for predicting SIRS. The diagnostic performances of the risk factors were evaluated by receiver operating characteristic (ROC) curve analysis. RESULTS: Among the 189 patients, 49.7% (94/189) had preexisting FL. On CT, AP patients with preexisting FL were more likely to develop necrosis (23.4% vs 10.5%, p=0.021), local complications (45.7% vs 29.5%, p=0.025) and persistent SIRS (59.6% vs 27.4%, p<0.001). Multivariate analysis showed that preexisting FL (OR=2.863, 95% CI: 1.264–6.486, p=0.012), APACHE II≥6 (OR=1.334, 95% CI: 1.117–1.594, p=0.002), and MCTSI ≥4 (OR=1.489, 95% CI: 1.046–2.119, p=0.027) could be independent risk factors for persistent SIRS. The areas under the ROC curve of preexisting FL, APACHE II, and MCISI in diagnosing AP patients with persistent SIRS were 0.664, 0.703, and 0.783, respectively. CONCLUSION: Patients with preexisting FL were more likely to develop necrosis and local complications on CT and present more severe AP and persistent SIRS. Preexisting FL can be an independent risk factor in predicting the presence of persistent SIRS in patients with AP.