In lipid-rich adenomas, attenuation measurements will be less than 10 HU. Unenhanced CT characterization of adrenal nodules relies on the detection of intracytoplasmic lipid found within adrenal adenomas, which reduces their CT attenuation. The purpose of this article is to present conventional and evolving technical aspects of adrenal imaging at both CT and MRI, discuss the role of CT and MRI for the diagnosis of common adrenal pathologic entities, and review the most current literature on the topic.ĬT characterization of adrenal nodules can be performed without or with the use of iodinated contrast material. Having an understanding of the various techniques used to image adrenal nodules with CT and MRI, the inherent strengths and limitations of these techniques, key distinguishing imaging features, and emerging techniques that may be used for improved adrenal nodule characterization is important. Although benign adenomas are overwhelmingly the most common adrenal nodule encountered in the general population, the possibility of other pathologic entities (including pheochromocytoma, adrenocortical carcinoma, and metastatic disease) requires that radiologists develop an approach to the characterization of adrenal lesions. The prevalence of adrenal incidentalomas increases with age fewer than 0.5% of adrenal nodules are discovered in patients in their 20s compared with up to 7% in patients older than 70 years old. Incidental adrenal nodules are detected in approximately 4–5% of patients undergoing CT examinations.

Adrenal nodule on kidney