How does CT imaging distinguish hemorrhagic from ischemic stroke in the acute phase?

• A. CT cannot distinguish
• B. Hemorrhage hyperdense; ischemia may be normal or hypodense early
• C. Hemorrhage hypodense
• D. Both hyperdense

Answer: (B)

In the acute phase, non-contrast CT distinguishes stroke types mainly by density differences. Fresh blood is highly attenuating, so hemorrhage appears bright (hyperdense) on CT. Ischemic tissue early on may look normal because cytotoxic edema hasn’t produced visible density changes yet, or it may start as subtle hypodensity as swelling develops. So the most reliable early distinction is that hemorrhage shows up as hyperdense, while ischemia may be normal or appear hypodense depending on timing. This is why CT is used first to rule out hemorrhage before considering treatments for ischemic stroke.