Investigation useful for detecting extra adrenal phecochromocytoma-
T2 weighted MRI with gadolinium contrast is optional for detecting pheochromocytoma and is somewhat better than CT for imaging extra adrenal pheochromocytoma and paragangliomas Ref ( Harrison 17 pg 2271)
USG
CCT
T2-weighted MRI with gadolinium contrast
MIBG
Endocrinology