A comparison of plasma-free metanephrines with plasma catecholamines in the investigation of suspected pheochromocytoma.

ObjectiveTo compare the diagnostic performance of plasma metanephrines by ELISA and plasma catecholamine measurements by HPLC in patients selected for clonidine suppression testing.MethodsPlasma catecholamines adrenaline (ADR) and noradrenaline (NOR) were measured by HPLC and metanephrine with norme