This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2018, Subject name: Surgery
Best way to localize extra-adrenal pheochromocytoma:- 
Select and explain. 
A. X-ray, B. Nucleotide scan, C. VMA excretion, D. Clinical examination
B: Nucleotide scan
Answer: B: Nucleotide scan 
Explanation: IOC for extra adrenal pheochromocytoma is MRI>MIBG scan(aka-nucleotide scan) Imaging MRI is IOC for adrenal, extra adrenal pheochromocytoma and in pregnancy MRI is 95% sensitive and 100% specific for pheochromocytoma CT scan should be performed without contrast administration to avoid hypeensive crisis. MIBG scan is useful for extra-adrenal pheochromocytoma but IOC is MRI even for extra adrenal pheochromocytoma. Biopsy is contraindicated as it precipitates hypeensive crisis