Ans. D. 14CT Scansa. Infarcts are detected after 24 - 48 hours.b. Fail to detect small ischemic stroke in the posterior fossa. Also fail to show small cortical infarctsc. Better than MRI in detecting early hemorrhaged. Infarct upto 12 hrs CT may be normal in cerebral infarct.e. Then low attenuations occur in 24-36 hrs ischemic tissue swells producing a mass effect by 2nd to 3rd day Subsides by 7th day.f. After 7 days infarcted tissue is invaded by phagocytic glial cell which increases attenuation So plain CT looks near normal.g. Same time infarcted area is also invaded by New Blood vessel which show an area of enhancement after iodinated contract media. Enhancement is maximum in 2nd week