CT findings of adrenal adenoma

Adrenal adenomas typically appear on CT (computed tomography) imaging as single, or occasionally multiple, round or oval density nodules. Common CT characteristics: 1. Size and morphology: Adenomas are generally 1 to 5 cm in diameter, with well-defined margins and regular shape. 2. Density: Most adrenal adenomas appear iso-attenuating or slightly hyperattenuating compared to normal renal parenchyma on non-contrast CT. Some lipid-rich adenomas may show lower density, similar to fatty tissue. 3. Enhancement pattern: On contrast-enhanced CT scans following intravenous administration of contrast agent, adenomas typically demonstrate varying degrees of enhancement—appearing brighter on images. This is referred to as "rim enhancement" or "homogeneous enhancement." 4. Perilesional features: There is usually no significant surrounding edema or infiltration, and the boundary between the adenoma and adjacent normal adrenal tissue is clearly demarcated. 5. Symmetry: When adenomas are present bilaterally, it is important to assess whether they appear symmetrically, as this may be a sign of genetic disorders such as Cushing's syndrome.