Pearls & oy-sters: hyperdense or pseudohyperdense MCA sign: a Damocles sword?

• The presence of a true hyperdense sign can be confirmed by measuring attenuation value as compared to the normal-appearing contralateral side. • Mimics of a hyperdense sign (i.e., a pseudohyperdense sign) include vascular calcification, raised hematocrit, and intravenous contrast medium. • Careful attention should also be paid to the surrounding brain parenchyma to assess for hypodensity or any differentiating features suggestive of tumor, infection, or contusion.