Different meaning of vessel signs in acute cerebral infarction.

A 64-year-old man presented with left-sided weakness with an initial NIH Stroke Scale score of 11. Brain CT imaging showed a hyperdense artery sign of right middle cerebral artery (MCA) occlusion (figure 1, A and B). Brain MRI showed the susceptibility vessel sign (SVS) on gradient recalled echo and hyperintense vessels (HV) on fluid-attenuated inversion recovery images (figure 1, C and D). Angiography demonstrated right MCA occlusion with well-developed pial collateral flow (figure 2). HV is not identical to hyperdense artery sign and SVS, which indicate intraluminal thrombus.1 HV may indicate slow collateral flow, not thrombus itself.2