Non-contrast CT head obtained 3 hours after onset of right hemiplegia and aphasia in a 62-year-old man shows a hyperattenuating left middle cerebral artery in the sylvian fissure. This finding represents:
- A Intraluminal thrombus in the MCA ✓
- B Calcification of the arterial wall
- C Contrast extravasation from prior angiography
- D Sylvian fissure subarachnoid hemorrhage
Correct answer: A. Intraluminal thrombus in the MCA
Explanation
The hyperdense (dense) MCA sign is an early non-contrast CT marker of acute large-vessel occlusion caused by intraluminal thrombus, visible within the first few hours and correlating with poor outcome and large infarct burden. It is distinguished from vessel calcification by its attenuation value and segmental appearance confined to the vessel lumen. Sylvian fissure subarachnoid hemorrhage follows the sulcal and cisternal contours rather than reproducing the cylindrical shape of the artery.
Reference: Osborn's Brain, 2nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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