Temporal assessment of pancreatic blood flow and perfusion following secretin stimulation using noninvasive MRI

Abstract

Purpose To dynamically quantify pancreatic perfusion and flow within the arteries supplying the pancreas in response to secretin stimulation. Materials and Methods Twelve healthy male subjects were scanned at 1.5T with arterial spin labeling to measure tissue perfusion and phase contrast magnetic resonance imaging (MRI) to measure vessel flow. Superior mesenteric (SMA), gastroduodenal (GDA), common hepatic (HA), and splenic (SA) arterial flow and pancreatic perfusion were serially measured for 50 minutes following 1 IU/kg intravenous secretin. The significance of differences between timepoints was tested using a repeated measures one-way analysis of variance (ANOVA). Results Baseline blood flow (mean±SEM or median [IQR]) for SMA, HA, SA, and GDA was 7.6±1.3, 4.0±0.5, 8.2±0.8, and 0.9 (0.8-1.4) ml/s, respectively. Baseline pancreatic perfusion was 200±25 ml/100g/min. Blood flow increased in the SMA (234%, P<0.0001) and GDA (155%, P=0.015) immediately after secretin injection. Reduced HA blood flow was observed after 10 minutes (P=0.066) with no change in SA flow (P=0.533). Increased pancreatic perfusion was maintained for 40 minutes after injection with a maximal increase at 5 minutes (16.8%, P=0.025). Conclusion Intravenous secretin resulted in significant temporal changes in pancreatic perfusion and arterial blood flow.