Final answer:
A head CT can reveal various conditions such as a calcified lesion, tumor, fracture, or infection. Each condition has specific appearances on CT, indicating differences in tissue density or bone continuity.
Step-by-step explanation:
A head CT (or computed tomography) scan is a diagnostic tool that can reveal various conditions based on differences in tissue density within the brain and cranium. When a CT scan indicates a lesion that appears adhered to the cranium in a 50-year-old male, it could represent a range of possibilities. A calcified lesion may be detected due to its high density compared to surrounding brain tissue. A tumor can also be visible on a CT scan, often manifesting as either a hyperdense (more dense than surrounding tissue) or a hypodense lesion (less dense), and might show irregular borders. In the case of a fracture, the scan would show a disruption in the continuity of the bone. Lastly, if the patient has an infection like meningitis, the CT might reveal inflammation of the meninges, although it's worth noting that other imaging modalities or tests are usually required to diagnose infections with higher specificity.