Imaging of Adrenal Masses.

Abstract

Adrenal lesions are common and require appropriate management when clinically relevant. The approach to the evaluation of an adrenal lesion is to exclude malignancy and hormone excess as these are associated with significant morbidity and mortality. Imaging of adrenal lesions primarily aims to identify features indicating benignity. Non-contrast CT is recommended as first-line imaging for adrenal lesions. Indeterminate lesions that require further characterization may proceed to adrenal protocol CT (with contrast) or MRI, with a trend in recent years towards increasing use of MRI. PET-CT may also be used to assess adrenal lesions in certain clinical scenarios. Clinical guidelines recommend that all adrenal incidentalomas require further dedicated imaging unless they are clearly benign on imaging. The imaging strategy of adrenal lesions depends upon a number of factors including patient history, nature of detection, imaging characteristics (size, heterogeneity, presence of intracellular lipid), and the presence or absence of hormone excess. Special considerations are given to pregnant patients, young patients < 40 years, and those with a history of an extra-adrenal malignancy. This review outlines the role of imaging for adrenal lesions, describes the various imaging options and investigation strategies, and highlights relevant imaging findings.