The Value of Postural Stimulation Test Combined with Adrenal CT in the Diagnosis of Aldosterone-producing Adenoma

  Objective  Adrenal vein sampling (AVS) and pathological report were selected as gold standard to assess the value of adrenal CT scan combined with postural stimulation test in diagnosing aldosterone-producing adenoma.

  Methods  The clinical data of primary aldosteronism (PA) patients including aldosterone-producing adenoma (APA) and idiopathic hyperaldosteronism (IHA) were retrospectively collected in the West China Hospital of Sichuan University. The sensitivity and specificity of adrenal CT scan combined with postural stimulation test in diagnosing APA were studied.

  Results  A total of 83 APA patients and 42 IHA patients were enrolled in this study. ROC curve was plotted with increase percentage of serum aldosterone in upright position compared with recumbent position. The optimal cutoff point for APA diagnosis by postural stimulation test was 11%, and the percentage less than 11% was taken as a positive result. The patients were diagnosed by postural stimulation test, with 60 cases positive and 23 cases negative in APA patients and 12 cases positive and 30 cases negative in IHA patients. When AVS and pathological report were selected as the gold standard, the sensitivity and specificity of postural stimulation test in diagnosing APA were 72.3% and 71.4% respectively. Among the 83 APA patients, 65 patients with unilateral nodules and 18 patients with bilateral nodules were diagnosed by CT scan. The coincidence rate in APA diagnosis between CT scan and AVS or pathological report was 78.3% (65/83). Among the 60 patients with positive result in postural stimulation test, who were diagnosed bilateral nodules by CT scan, 51 patients were diagnosed as APA by AVS or pathological report (51/60).

  Conclusion  Adrenal CT combined with postural test can increase the diagnostic accuracy of APA patients.