This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous system, Subject name: Radiology
Dense middle cerebral aery (MCA) Sign in brain is seen in 
Select and explain. 
A. Acute infarct, B. Subacute infarct, C. Subacute haemorrhage, D. Chronic infarct
A: Acute infarct
Answer: A: Acute infarct 
Explanation: The hyperdense MCA sign refers to the focally increased density of the middle cerebral aery on CT and is a direct visualization of thromboembolic material within the lumen. It is thus the earliest visible sign of MCA infarction as it is seen within 90 minutes after the event - acute infarct. It is the longitudinal equivalent of the MCA dot sign and hyperdense basilar tip sign.