A variety of methods have been used to localize pheochromocytomas and paraganliomas.CT and MRI are similar in sensitivity. T2 weightd MRI with gadolinium contrast is optimal for detecting pheochromocytoma and is somewhat better than CT for imaging extraadrenal pheochromocytoma. Pheochromocytomas can also be localized using radioactive traces including 1311 or 1231 - metaiodobenzylguanidine (MIBG), 111/n- somatostatin analogue or 18f dopa."The sensitivity of MIBG scanning with Pil for pheochromocytoma is 100% and specificity 95-98% making it the most useful investigation for the localisation of pheochromocytoma including those that arise at nonadrenal sites". Bone & mineral metabolism : Alkaline phosphatase