Prevalence of imaging findings of acute pancreatitis in emergency department patients with elevated serum lipase

To assess the association of imaging features of acute pancreatitis (AP) with the magnitude of lipase elevation in Emergency Department (ED) patients.This Institutional Review Board-approved retrospective study included 509 consecutive patients presenting from 9/1/13-8/31/15 to a large academic ED with serum lipase levels ≥3× the upper limit of normal (ULN) (≥180 U/L). Patients were excluded if they did not have imaging (n = 131) or had a history of trauma, abdominal metastases, altered mental status, or transfer from an outside hospital (n = 190); the final study population was 188 patients. Imaging exams were retrospectively evaluated, and a consensus opinion of two subspecialty-trained abdominal radiologists was used to diagnose AP. Primary outcome was presence of imaging features of AP stratified by lipase level (≥3×-10× ULN and10× ULN). Secondary outcome was rate of discordant consensus evaluation compared to original radiologist's report.25.0% of patients (47/188) had imaging features of AP. When lipase was10× ULN (n = 94), patients were more likely to have imaging features of AP (34%) vs. those with mild elevation (16%) (p = 0.0042). There was moderately strong correlation between lipase level and presence of imaging features of AP (r = 0.48, p0.0001). Consensus review of CT and MRI images was discordant with the original report in 14.9% (28/188) of cases.Prevalence of imaging signs of AP in an ED population with lipase ≥3× ULN undergoing imaging is low. However, the probability of imaging features of AP increases as lipase value increases.