Which is the best test for Conn syndrome?

(IOC) Best test for Conn's syndrome: Salt-loading test/Saline infusion test Screening test: Plasma aldosterone renin ratio * In patient with conn's syndrome, the plasma aldosterone levels || d/t tumor which causes endogenous production of aldosterone Therefore, Aldosterone levels are elevated, the RAAS system has negative feedback so Plasma Renin activity reduces. So Aldosterone Renin Ratio (increased) Since, Plasma aldosterone increased (d/t tumor) & Plasma renin || Option D- Low renin levels are seen in Both Conn's & Liddle's syndrome so only renal vein renin levels alone cannot be helpful for diagnosis.