How early does the non-contrast head CT indicate ischemic stroke?
Analysis of the NINDS data shows that early ischemic changes are quite common in ischemic stroke, occurring in 31% within 3 hours of stroke onset, in contrast to the widely held belief that ischemic strokes become visible on CT only after 6 hours [32,33]. Some findings may occur immediately, such as the hyperdense MCA sign, while other findings may require time to elapse, with the gradual failure of ATP-dependent ion pumps and resulting fluid shifts.
