(Reproduced, with permission, from Findling JW, et al (Reproduced, with permission, from Findling JW, et al. Selective venous sampling for ACTH in Cushing's syndrome: differentiation between Cushing's disease and the ectopic ACTH syndrome. Ann Intern Med. 1981;94:647). Source: Chapter 4. Hypothalamus and Pituitary Gland, Greenspan’s Basic & Clinical Endocrinology, 9e Citation: Gardner DG, Shoback D. Greenspan’s Basic & Clinical Endocrinology, 9e; 2011 Available at: http://accessmedicine.mhmedical.com/DownloadImage.aspx?image=/data/books/gard9/gard9_c004f004.gif&sec=39744466&BookID=380&ChapterSecID=39744044&imagename= Accessed: October 18, 2017 Copyright © 2017 McGraw-Hill Education. All rights reserved