Fluorodopa F 18 in Congenital Hyperinsulinism and Insulinoma

Inclusion Criteria: * Patients with HI attending the Cook Children's Congenital Hyperinsulinism Center and being treated by an Endocrinologist which may be the PI or a partner of this clinician. * The patient's Endocrinologist has determined that the patient cannot be safely managed with standard medical therapy (failed) and surgery is recommended to prevent future episodes of severe hypoglycemia and preserve brain function. Failure of medical therapy is defined as both: * Hypoglycemia (blood glucose \<70 m/dL) on a single measure despite the use of anti-hypoglycemic medications, if applicable to the individual patient, including and limited to diazoxide or octreotide * Inability to fast, defined as the inability to maintain a blood glucose \>50 mg/dL for: 1) more than 12 hours for infants \< 1 year of age; 2) more than 15 hours 1-3 years of age; 3) more than 18 hours over 3 years of age * Patients in whom the genetic testing (if available and informative) does not prove diffuse HI disease. Such children might be considered if they have one or more of the following situations: * no genetic testing results (e.g., due to insurance denial or parental refusal) * negative genetic testing (note: only 75% of mutations may be found with existing technology) * no autosomal recessive mutations in ABCC8 or KCNJ11 on the maternal allele * no autosomal dominant mutations in ABCC8 or KCNJ11 * Patients thought to have focal HI disease based on genetic testing or insulinoma based on clinical evaluation and have well-controlled blood glucose levels with any degree of dietary or medical management, BUT the patient and their parent(s) or LAR wishes to proceed with surgery for a possible cure of HI disease. Exclusion Criteria: * Patients who do not have a diagnosis of HI * Patients with genetic evidence of diffuse HI * Patients who are pregnant * Nursing mothers who are unwilling to discontinue breastfeeding their infant for 48 hours after Fluorodopa F 18 injection * Patients with a known allergy to Fluorodopa F 18 agent