Quantitative imaging biomarkers in the assessment of adrenal nodules

Incidental adrenal nodules provide a diagnostic conundrum. Current imaging techniques have demonstrated success in identifying lipid-rich adenomas, however, are limited in detecting malignancy and assessing for functionality. Imaging biomarkers are objective characteristics derived from imaging that may measure normal or pathological processes or assess response to therapy. Recent attempts have been made to standardize the measurement of the most common imaging biomarkers used in assessing the adrenal gland, offering a path to more uniform research in this area. The aim of this review is to describe the imaging biomarkers used in adrenal imaging and assess the evidence supporting their use.