current concepts on the diagnostic use of mibg in children metaiodobenzylguanidine mibg was developed 18 yr ago for scintigraphic imaging of the adrenomedullary tumors pheochromocytoma and neuroblastoma many studies have shown the usefulness of this agent for the management of patients with neuroblastoma or pheochromocytoma and the 131ilabeled form was recently approved by the food and drug administration for use in the us this article summarizes our current concepts on the diagnostic use of mibg in children the radioisotopes available for labeling of mibg and related compounds the dosimetry metabolism and mechanisms of uptake and retention are discussed our protocols for imaging both 131imibg and 123imibg along with the normal distribution of these compounds are reviewed the use of mibg for the management of neuroblastoma and comparisons with other radiotracers available for imaging neuroblastomas are also addressed