1.5 cm incidental adrenal nodule, with attenuation of 26 HU on routine CT is indeterminate. Per ACR white paper, a 12 month follow-up CT/MR should be considered, given that the nodule is homogeneous and low-density.
Virtual non-contrast shows attenuation of -7 HU, confirming benign adenoma.
A true non-contrast exam was performed 6 months later, which shows nodule is stable with an attenuation of -10 HU. A virtual non-contrast scan can, in most situations, substitute for a true non-contrast scan.