<prompt> Answer this question truthfullyWhat test should be performed to determine ACTH levels after a diagnosis of Cushings syndrome has been made using 24 hour urine cortisol, late night salivary, or low-dose dexamethasone suppression tests?  <response>: <reason> After determining someone has Cushings syndrome using 24 hour urine cortisol, late night salivary, or low-dose dexamethasone suppression tests, one needs to test ACTH levels. 