Splenic and perisplenic involvement in acute pancreatitis: Determination of prevalence and morphologic helical CT features

Purpose: The purpose of this work was to determine the prevalence and morphologic helical CT features of splenic and perisplenic involvement in patients with acute pancreatic inflammatory disease in correlation with the severity of the pancreatitis. Method: One hundred fifty-nine contrast-enhanced helical CT scans of 100 consecutive patients with acute pancreatitis were reviewed retrospectively and independently by three observers. CT scans were scored using the CT severity index (CTSI): Pancreatitis was graded as mild (0-2 points), moderate (3-6 points), and severe (7-10 points). Interobserver agreement for both the CTSI and the presence of splenic and perisplenic involvement was calculated (κ statistic). Correlation between the prevalence of complications and the degree of pancreatitis was estimated using the Fisher exact test. Results: The severity of pancreatitis was graded as mild (n = 59 scans), moderate (n = 82 scans), and severe (n = 18 scans). Splenic and perisplenic abnormalities detected included perisplenic inflammatory fluid collections (95 scans, 58 patients), narrowing of the splenic vein (35 scans, 25 patients), splenic vein thrombosis (31 scans, 19 patients), splenic infarction (10 scans, 7 patients), and subcapsular hemorrhage (2 scans, 2 patients). No cases of splenic artery pseudoaneurysm formation, intrasplenic venous thrombosis, intrasplenic pseudocysts, or abscesses were detected. The interobserver agreement range for scoring the degree of pancreatitis and the overall presence of abnormalities was 75.5-79.2 and 71.7-100%, respectively. A statistically significant difference between the presence of abnormalities and the severity of pancreatitis was observed (p < 0.001). Conclusion: Splenic vein thrombosis (19%) and splenic infarction (7%) are relatively common CT findings in association with acute pancreatitis. The CTSI proves to be accurate in predicting these complications as there is a statistically significant correlation between the prevalence of these complications and the severity of pancreatitis.