This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
Which one of the following imaging modalities is most sensitive for evaluation of extra- adrenal phaeochromocytoma. 
Select and explain. 
A. Ultrasound, B. CT, C. MRI, D. MIBG scan
D: MIBG scan
Answer: D: MIBG scan 
Explanation: D i.e. MIBI Scan Pheochromocytoma arises from paraganglion cellsQ (autonomic nervous system). M. C. site of origin is adrenal medullaQ M. C. extra-adrenal site is paraveebral sympathetic ganglion in organ of zuckerkandlQ (near aoic bifurcation) Investigation of choice for adrenal pheochromocytoma is CT ScanQ followed by MRI (d/t low cost) Investigation of choice for locally recurrent, metastatic, Ectopic & Extra - adrenal pheochromocytoma is metaiodobenzylaguanidine (MIBG) ScanQ (using P23 or 1131). Sensitivity of imaging modalities