Royal Rouf

Subarachnoid hemorrhage (SAH) is bleeding into the subarachnoid space—the area between the arachnoid membrane and the pia mater surrounding the brain. Symptoms may include a severe headache of rapid onset, vomiting, decreased level of consciousness, fever, weakness, numbness, and sometimes seizures.

The provided image is a non-contrast CT scan of the brain showing significant abnormal findings. Most notably, there is hyperdense (bright white) material within the normally dark, fluid-filled subarachnoid spaces.
Hyperdense Basal Cisterns: Bright white material fills the central cisterns around the midbrain, creating a characteristic "star-shaped" pattern.
Sulcal and Fissural Involvement: Hyperdensity is visible extending into the Sylvian fissures bilaterally and the anterior interhemispheric fissure.
Asymmetry: There appears to be a larger, focal area of hyperdensity in the left posterior region compared to the right, which may indicate a primary source of bleeding or a localized clot.
Potential Considerations
The appearance is highly consistent with acute subarachnoid hemorrhage (SAH), where blood fills the spaces normally occupied by cerebrospinal fluid (CSF). This is often considered a medical emergency.
Differential possibilities for hyperdense areas on a brain CT include:
Aneurysmal Subarachnoid Hemorrhage: The most common non-traumatic cause, often due to a ruptured berry aneurysm.
Traumatic Subarachnoid Hemorrhage: Resulting from head injury, typically more localized near the site of impact but can be diffuse.
Hyperdense Neoplasms: Certain highly cellular or calcified tumors (e.g., lymphoma, medulloblastoma) can appear bright on CT.