[Nuclear medicine diagnosis of adrenal gland diseases]

Localization procedures are required in adrenal diseases after biochemical confirmation of hormonal excess. Whereas computed tomography, ultrasound and--in rare cases--also magnetic resonance are needed to image the morphological abnormalities and the anatomy of neighbouring structures, adrenocortical and adrenomedullary scintigraphy is dependent on a functioning adrenal gland. Adrenocortical scintigraphy has the advantage of being able to differentiate between unilateral adenoma and bilateral hyperplasia in patients with primary hyperaldosteronism. It is of minor significance in patients with Cushing's syndrome or hyperandrogenism. In patients with catecholamine-producing tumours scintigraphy with radioiodine-labelled meta-iodobenzylguanidine (MIBG) may detect intra- and extra-adrenal, uni- and bilateral or multilocular, benign and malignant lesions. In patients with malignant but inoperable phaeochromocytoma, therapy with high doses of MIBG may improve clinical symptoms and reduce tumour volume.