Imaging of Adrenal Incidentalomas and Their Mimics: A Practical Update for Risk Stratification and Management from a Precision Imaging Perspective

Background/Objectives: To provide an updated overview of adrenal incidentaloma evaluation, characterize the principal imaging mimics across pediatric and adult populations, and propose a clinically actionable approach integrating endocrine assessment with conventional and advanced imaging.

Methods

A narrative review of recent evidence and major international recommendations was performed, focusing on epidemiology, endocrine work-up, non-contrast computed tomography (CT), washout CT, magnetic resonance imaging (MRI), and dual-energy CT (DECT).

Results

The recent literature has questioned a uniformly washout-centered approach and has raised interest in more selective, risk-adapted strategies based on clinical context, endocrine profile, and lesion phenotype; however, these proposals should be distinguished from established guideline recommendations. Non-contrast CT remains the cornerstone of first-line characterization, particularly for identifying lipid-rich adenomas. However, the routine use of adrenal washout CT is increasingly questioned, especially in true incidentalomas, because many benign adenomas are lipid-poor and several non-adenomatous lesions may show overlapping washout behavior. In this setting, MRI maintains a key problem-solving role, mainly through chemical shift imaging. DECT represents the most promising technical advance, enabling multiparametric characterization through virtual non-contrast images, iodine quantification, and material decomposition, with the potential to improve the assessment of indeterminate lesions while reducing unnecessary multiphasic imaging and radiation exposure.