iodine-123 metaiodobenzylguanidine

The neurotransmitter analogue 3-nitrobenzylguanidine conjugated to iodine I 123 and used as a gamma-emitting imaging agent. The adrenergic tissue uptake and storage of I-123 metaiodobenzylguanidine (I-123 MIBG) mimics that of norepinephrine (NE). The distribution of this agent enables the scintigraphic imaging of neural crest tumors, such as neuroblastoma and pheochromocytoma.