The corticotropin-releasing hormone (CRH) stimulation test
helps determine whether a
pituitary tumor may be causing
Cushing's syndrome. It is sometimes done with an inferior
petrosal sinus sampling (IPSS) test.
In these tests, a small tube (catheter) is used
to collect samples from blood vessels coming from the pituitary gland near the brain and also from a vein in your arm. You will get an injection of CRH, and samples of your blood near your pituitary gland and from your arm are taken.