Stroke window setting is used to optimize visual depiction of subtle loss of gray-white matter differentiation. Window level of 32 Hounsfield unit (HU) and width of 8 HU has been shown to improve sensitivity in detection of acute ischemic stroke on CT. The sensitivity is increased from 57% to 71% compared to normal window setting (level of 20 HU and window width of 80 HU) ¹.