Hyperinsulinemic hypoglycemia is caused by low glucose due to excessive insulin secretion and remains difficult to treat because of the requirement for extensive amounts of glucose and the lack of effective long-term medical therapy. Correct diagnosis, localization, and limited excision of the focal lesion will result in a complete cure of the patient. In contrast, medically unresponsive diffuse disease requires a near total pancreatectomy, greatly increasing the risk of future diabetes mellitus. Fortunately, \[18F\]-DOPA PET has been shown to be a useful noninvasive imaging method for distinguishing between focal and diffuse forms of hyperinsulinemic hypoglycemia. In this study, the investigators seek to validate the effectiveness of using PET/MR and PET/CT with F-DOPA to accurately and reliably detect and localize disease.