This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Adrenal Gland, Subject name: Medicine
A 20-year-old hypeension patient has been diagnosed as a case of pheochromocytoma with positive biochemical evidence. What is the next step in work up of this patient? 
Select and explain. 
A. MRI Abdomen, B. Perform urinary VMA levels, C. Perform adrenal vein sampling, D. MIBG scintigraphy
A: MRI Abdomen
Answer: A: MRI Abdomen 
Explanation: Option A: 1st imaging of the Abdomen should be done in pheochromocyte in patient to locate whether it is adrenal or extra adrenal pheochromocytoma. If site of Tumor is not located means tumor is less than 1 cm, then MIBG scintigraphy should be done in patient. Screening Test= 24 hr.Urinary fractionated metanephrine levels. IOC: Plasma metanephrine level Imaging - MRI Abdomen If size <1cm Tumor 1. MIBG scan= for Adrenal Pheochromocytoma (Metaiodobenzyl guanidine scan) 2. PET DOPA= For Extra Adernal Pheochromocytoma.