An exocrine pancreatic stress test with¹¹C-acetate PET and secretin stimulation

The purpose of this study was to develop a noninvasive imaging test of pancreatic exocrine function. Methods: In this pilot study, 5 healthy volunteers underwent two 60-min dynamic ¹¹C-acetate PET studies, one before and one after intravenous secretin administration. Kinetic analysis of the pancreas was performed using a 1-compartment model and an image-derived input function. From summed images, standardized uptake values were measured from the pancreas and the liver, and the pancreas-to-liver ratio was computed. Results: The baseline k₁ and k₂ data for all 5 volunteers were consistent. After secretin stimulation, the k₁ and k₂ significantly increased (paired t test P = 0.046 and P = 0.023, respectively). In the summed PET images, the pancreas-to-liver ratio decreased (P = 0.037). Increased ¹¹C-acetate activity was observed in the duodenum after secretin stimulation consistent with secretin-induced secretion. Conclusion: ¹¹C-acetate PET studies with secretin stimulation show potential as a noninvasive method for assessing pancreatic exocrine function.