Bilateral Inferior Petrosal Sinuses Sampling in the Routine Investigation of Cushing's Syndrome: A Comparison with MRI

OBJECTIVE: Identifying the cause of Cushing's syndrome (CS) is a perplexing issue. Bilateral inferior petrosal sinuses sampling (BIPSS) is an invasive and elaborate but established procedure in distinguishing Cushing's disease (CD) from ectopic adrenocorticotropic hormone (ACTH) syndrome. We compare the diagnostic performance of BIPSS and MRI in detecting an ACTH-secreting source, and we suggest the diagnostic protocol that we found beneficial for the management of patients with CS.MATERIALS AND METHODS: Seventy-eight consecutive patients with CS were included. All patients underwent biochemical investigation and pituitary MRI. Consequently, patients were routinely referred for BIPSS; 25 received stimulation with corticotropin-releasing hormone (CRH) and 53 with CRH and desmopressin. The diagnosis of CD was established on the basis of complementary biochemical, imaging, and BIPSS criteria. The diagnostic performances of BIPSS and MRI were calculated for patients with final diagnosis.RESULTS: A final diagn...