The application of bilateral inferior petrosal sinus sampling in diagnosing ACTH-dependent Cushing's syndrome

Objective: To discuss the clinical values of bilateral inferior petrosal sinus sampling (BIPSS) in diagnosing ACTH-dependent Cushing's syndrome (CS). Methods: BIPSS and pituitary MRI examination were performed in 43 patients with CS, which was followed by pituitary surgery later. The clinical data and imaging findings were retrospectively analyzed. The diagnostic values of the two kinds of examinations were analyzed by receiver operating characteristic (ROC) curve and were compared with the area under the ROC curves (AUC). Results: In making the qualitative diagnosis of CS with BIPSS, the sensitivity, specificity, positive predictive value and negative predictive value was 0.95, 1.00, 1.00 and 0.71 respectively, while the AUC was 0.97, which was larger than that obtained from MRI. In making the diagnosis of the lesion's localization for Cushing's disease, the accuracy of BIPSS was 84.21%, which was much higher than that of pituitary MRI. Conclusion: BIPSS can be safely and successfully performed in most cases. With excellent diagnostic accuracy, both qualitative and localizing, BIPSS should be regarded as a useful and reliable method in diagnosing ACTH-dependent CS. (authors)