**Core Concept**
Adrenal adenomas are benign tumors of the adrenal gland, and their characteristics can be distinguished using computed tomography (CT). Understanding the CT features of adrenal adenomas is crucial for accurate diagnosis and differentiation from other adrenal lesions.

**Why the Correct Answer is Right**
Adrenal adenomas typically exhibit low attenuation (density) values on unenhanced CT scans due to their high lipid content. They also show rapid washout of contrast in the early arterial phase, which is a characteristic feature of benign adenomas. Additionally, adrenal adenomas may exhibit a distinct "halo sign" or "washout sign" on delayed images.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because non-contrast attenuation values in adrenal adenomas typically range from -20 to 10 Hounsfield units (HU), which is not a characteristic feature of this option.
**Option B:** This option is incorrect because adrenal adenomas do not typically exhibit calcification, which is more commonly associated with other types of adrenal lesions.
**Option C:** This option is incorrect because adrenal adenomas do not typically exhibit a high attenuation value on unenhanced CT scans, which is more characteristic of hemorrhagic lesions or malignant tumors.

**Clinical Pearl / High-Yield Fact**
Remember that the "halo sign" or "washout sign" on delayed CT images is a key feature of adrenal adenomas, which can help differentiate them from other adrenal lesions.

**Correct Answer: B. Calcification**