Acute Pancreatitis Associated With Pleural Effusion Multi-slice CT Manifestations And Anatomical Basis

Objective: To study the patterns of pleural effusion diffusion on CT inacute pancreatitis, anatomic pathways of peripancreatic effusion draining topleural, as well as correlations of pleural effusion with the severity of acutepancreatitis according to the CT severity index (CTSI) and the AcutePhysiology And Chronic Healthy Evaluation Ⅱ(APACHE Ⅱ) scoringsystem.Methods: From January1st2010and May1st2012,119patients withacute pancreatitis admitted to our institution were included in this study.Abdominal CT (covering the lower chest) was performed within48h afteradmission. The prevalence and semiquantitative of pleural effusion on CTwere noted. The semiquantitative was rated according to the area of pleuraleffusion on CT at the level of diaphragmatic muscle. The anatomicalpathways of peripancreatic effusion draining to pleural were analyzed. Theseverity of acute pancreatitis was graded with CT severity index (CTSI) andAcute Physiology And Chronic Healthy Evaluation II (APACHE II) scoringsystem. Spearman correlation of pleural effusion rating with the CTSI and theAPACHEII scoring system was analyzed.Results: In119patients with acute pancreatitis,74.8%(89/119) ofpatients had pleural effusion on CT, including47.19%(42/89) of patientswith a small amount of pleural effusion,33.70%(30/89) of patients withmoderate amount and19.10%(17/89) of patients with a large number ofpleural effusion. The anatomic pathways of peripancreatic effusion draining to pleural included esophageal hiatus in33.7%(30/89) of patients, aortichiatus in6.7%(6/89) of patients and inferior vena cava hiatus in3.37%(3/89)of patients. The rating of pleural effusion on CT was correlated with CTSIscores (r=0.449, P=0.000) and was slightly correlated with the APACHEIIscores (r=0.197, P=0.016).Conclusion: Pleural effusion on CT in acute pancreatitis is common Itcould be from the diffusion of peripancreatic effusion through thediaphragmatic muscle hiatus, and may be a supplementary indicator indetermining the severity of AP.