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 Pheochromocytoma – 
Select and explain. 
A. Ultrasound, B. CT, C. MRI, D. MIBG scan
D: MIBG scan
Answer: D: MIBG scan 
Explanation: MIBG is taken up by catecholamine granules and is used mainly for localizing pheochromocytomas in the adrenal and in extra-adrenal sites and for the detection of metastasis.