What imaging finding is characteristic of sub-arachnoid hemorrhage on a CT scan?

The characteristic imaging finding of subarachnoid hemorrhage on a CT scan is the "starfish pattern." This appearance is indicative of blood that has spread throughout the subarachnoid space, particularly around the cerebral vessels and sulci, causing a radiological pattern that resembles a starfish. The radiodense blood can outline the sulci and gyri, which is seen best in the basal cisterns and can extend outwards.

This pattern is critical in diagnosing subarachnoid hemorrhage quickly, especially in emergency settings, as timely detection can significantly impact patient outcomes. Early intervention is essential for preventing complications such as re-bleeding or vasospasm, thus making the ability to recognize this imaging finding even more vital for healthcare providers.

Other potential findings, such as cloudy appearance in the brain tissue, complete emissivity throughout the cerebral cortex, or localized swelling at the site of injury, are typically associated with other forms of brain pathology or types of hemorrhages and do not specifically point to subarachnoid hemorrhage.