Hyperdense Middle Cerebral Artery Sign

Axial CT image (narrow window) shows a hyperdense left MCA, representing an intraluminal thrombus.

Hyperdense MCA Sign

• Visualization of high density middle cerebral artery due to presence of intraluminal thrombus
• Specific sign for thrombotic MCA occlusion, but it is not sensitive
• Associated with poor prognosis and higher risk of hemorrhage if thrombolyzed
• Early resolution indicates successful reperfusion and favorable outcome after thrombolysis

Imaging Differentials

• Intraluminal thrombus
• High hematocrit (usually bilateral)
• Calcified plaque (usually bilateral)

Reference:

Rabinstein AA, Resnick SJ. Practical Imaging in Stroke: a Case-based Approach, 2009.