• Non-enhanced Brain CT (NECT) offers low yield in terms of its diagnostic utility for acute ischemic stroke (AIS), with sensitivities less than 67% at 3 hours out from symptom onset.

• A hyperdense middle cerebral artery (MCA) sign may represent acute thrombus and predicts impending large territorial infarct of poor prognosis (*see images of MCA Sign (left) and subsequent territorial edema representing infarct (right) below).

• While MCA Signs occur somewhat rarely, this finding is one of the earliest and most useful indicators of probable (clinical) stroke on NECT, and should be a recognizable hallmark for the emergency physician.

• Note that hyperdense MCA's can mimic a thrombus and actually represent atherosclerotic calcifications.

 

References

• Latchaw RE, et al. Recommendations for Imaging of Acute Ischemic Stroke: A Scientific Statement from the American Heart Association. Stroke 2009; 40: 3646-3678.
• Neuroradiology Teaching Files. Part Forty-five. Hyperdense MCA Sign. uhrad.com.