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: Surgery
How will you localize pheochromocytoma : 
Select and explain. 
A. Clinical examination, B. VMA excretion, C. CT scan, D. X-ray
C: CT scan
Answer: C: CT scan 
Explanation: Radiologic studies are useful to localize Pheochromocytoma and to assess the extent of spread once the diagnosis has been made with biochemical tests. CT scans are 85 to 95% sensitive and 70 to 100% specific for pheochromocytomas. CT scans do not provide functional information and cannot definitively diagnose pheochromocytomas. MRI scans are 95% sensitive and almost 100% specific for pheochromocytomas because these tumors have a characteristic appearance on T2-weighted images or after gadolinium. MRI is also the study of choice in pregnant women as there is no risk of radiation exposure. Ref : Lal G. (2010). Chapter 38. Thyroid, Parathyroid, and Adrenal. In T.R. Billiar, D.L. Dunn (Eds), Schwaz's Principles of Surgery, 9e.