Principle: The radiopharmaceutical, as a noradrenaline analogue, accumulates in the catecholamine secretory granules of neuroendocrine tissues. Indications: Pheochromocytoma neuroblastoma carcinoid medullary thyroid carcinoma gastrinoma insulin glucagonoma vipoma adrenal medullary hyperplasia Patient preparation: 2 days before application, on the day of application and 3 days after application thyroid blockade with chlorigen discontinuation of tricyclic antidepressants, some antihypertensives and cardiovascular drugs, sympathomimetics Duration of examination: This is a 2-day examination Radiopharmaceutical: 123I – metajodbenzylguanidine Method of administration: Intravenous Examination methodology: The radiopharmaceutical is injected intravenously into the patient and the first scan is performed 4 hours after application. The patient lies down on the gamma table and we take a full body scan. The scan takes about 30 minutes. The next part of the scan takes place 24 hours after application. We first perform a full-body scan followed by a targeted SPECT.  The scanning time is approximately 1.5 hours.