Review of Related Diseases (RRD) 10 – Disorders of the Neurological System Practice Test

On a non-contrast CT scan, acute hemorrhage appears as a bright, hyperdense area because fresh blood has higher attenuation than surrounding brain tissue. This increased density is due to the concentrated hemoglobin in the clot, which absorbs more X-rays than the normal brain parenchyma. As the hematoma evolves over hours to days, its density changes: it can become isodense or hypodense as hemoglobin breaks down and water content increases, making older bleeds harder to detect. Other findings like an iso-intense cortex suggest normal tissue, edema typically looks hypodense from increased water, and calcified plaques are dense due to calcium but indicate chronic changes, not an acute bleed. So a bright, hyperdense area on a non-contrast CT best signals an acute hemorrhage.