Patterns of salivary gland uptake in I-131 MIBG scintigraphy.

I-131 MIBG scintigraphy is routinely used in the diagnosis of neuroendocrine tumours with high specificity. The radiopharmaceutical is taken up via uptake mechanism and actively transported into storage vesicules. The organs with dense sympathetic innervation such as salivary glands, heart, lachrymal glands, spleen and rarely adrenal medulla are normally visualized with I-131 MIBG. Asymetrical salivary gland uptake is important in a patient with suspected neuroendocrine tumours. Absence of radioactivity may be a result of sympathic denervation or tumor. Bilateral radioactivity absence is observed usually due to drugs or radiopharmaceutical storage conditions. Detailed examination of cervical region is crucial for localisation of neuroendocrine tumours. Therefore, possible false positives should be kept in mind.