Imaging of adrenal masses

Abstract

This review aims to outline recent developments in adrenal imaging and characterization. Controversies in the management of adrenal incidentalomas will be addressed. Evaluation of density readings on unenhanced computed tomography and on contrast-enhanced delayed series has tremendously improved the characterization of adrenal masses. Attenuation measurements may, however, vary between different scanner types and may also be influenced by patient factors and the scanning technique. Evaluation of the mean percentage washout for adrenal masses on delayed enhanced computed tomography series is independent of such factors and allows the characterization of adrenal lesions with high sensitivity and specificity. In magnetic resonance imaging, dynamic gadolinium-enhanced and chemical-shift techniques have significantly improved the characterization of adrenal masses. Nuclear medicine studies prove to be useful adjuncts. Controversial reports have been published on the role of positron emission tomography/computed tomography in adrenal imaging. Adrenal venous sampling may allow differentiation of aldosteronoma and idiopathic hyperaldosteronism. Recent developments in adrenal mass imaging have improved the characterization of adrenal mass lesions. The need for histology sampling of incidentally discovered adrenal masses has been significantly reduced due to the high specificity of these new techniques. Controversies still exist regarding the optimal strategy for hormonal screening of a patient with an incidentally detected adrenal mass.