Indications: 1. Localization and diagnosis of pheochromocytoma. 2.Determination of the site and extent of malignant pheochromocytoma metastases. 3.Detection of residual lesions or recurrent foci of pheochromocytoma after surgery. 4.Adjuvant diagnosis of adrenal medullary hyperplasia. 5.CT or ultrasound examination of suspicious adrenal lesions, who need further information on the nature and functional status of the lesions. 6.Follow up observation after 131I-MIBG treatment for malignant pheochromocytoma. 7. Adjuvant diagnosis of other neuroendocrine tumors such as neuroblastoma. 8.Differential diagnosis of unexplained hypertension.