What are the methods used to diagnose a pheochromocytoma?

Pheochromocytoma is typically diagnosed using a combination of biochemical tests and imaging studies. Biochemical tests include measuring plasma free metanephrines or 24-hour urinary fractionated metanephrines, which are metabolites of catecholamines. Imaging studies such as computed tomography (CT) or magnetic resonance imaging (MRI) are employed to localize the tumor once biochemical evidence is confirmed. In some cases, additional imaging techniques like positron emission tomography (PET) may be used for further evaluation.