Normal Adrenal (Nuc) Fig. 25.16 Imaging of the adrenal medulla and neuroendocrine tumours with 123I (MIBG) meta-iodobenzylguanidine at 24 hours, posterior view. Normal appearance of the liver and two adrenal medullae are seen. Radioiodinated MIBG has been used both for the diagnosis and treatment of phaeochromocytomas, paragangliomas, neuroblastomas, carcinoid tumours and medullary carcinomas of the thyroid. Due to its structural similarity to noradnenaline it is taken up by the adrenal medulla and other tissues with rich sympathetic innervation, mostly via the neuronal uptake-I system. See later: • Normal Adrenal (Ven) • Normal Adrenal (CT) • MIBG