Normal adrenal asymmetry: explanation and interpretation.

Although adrenal imaging with 19-iodocholesterol provided much useful diagnostic information, spatial resolution was less than ideal. With the greater target-to-background ratios afforded by NP-59, differences between the right and left adrenal glands--in terms of position, configuration, and depth-related activity--can now be defined. Analysis of the scintigrams of 21 individuals with no evidence of adrenal disease has allowed us to characterize the normal degree of adrenal asymmetry. Appreciation of this asymmetry is necessary if the potential for greater diagnostic accuracy afforded by NP-59 is to be realized.