RT Journal Article SR Electronic T1 Limited Significance of Asymmetric Adrenal Visualization on Dexamethasone-Suppression Scintigraphy JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 43 OP 48 VO 26 IS 1 A1 Milton D. Gross A1 Brahm Shapiro A1 John E. Freitas YR 1985 UL http://jnm.snmjournals.org/content/26/1/43.abstract AB To assess whether a single measurement of the adrenal uptake of 6β-[131I]-iodomethylnorcholesterol (NP-59) on constant dexamethasone suppression would allow discrimination of adenoma from normal and bilateral hyperplasia, the adrenal uptake of 6β[131I]iodomethylnorcholesterol (NP-59) was determined in 50 patients with primary aldosteronism (30 adenoma, 20 hyperplasia) and in 13 with hyperandrogenism (six adenoma, seven hyperplasia). Bilateral adrenal NP-59 activity at 5 days was seen in 14 of 36 patients with adenoma (normal to adenoma ratio of ≥0.5), whereas marked asymmetric uptake of NP-59 was seen in six of 27 patients with hyperplasia (uptake ratio of ≤0.5). Thus the level of adrenal NP-59 uptake does not alone serve to distinguish either adenoma from the normal, contralateral adrenal or the adrenal glands in bilateral hyperplasia in all cases. It appears that the pattern of adrenal imaging, early unilateral or early bilateral NP-59 activity (<5 days after NP-59 on 4 mg dexamethasone), best serves to separate adrenal adenoma from bilateral hyperplasia.