Pattern recognition in severe displacement of the thalamostriate and internal cerebral veins: the W and infinity signs

Severe displacement of the thalamostriate and internal cerebral veins from the midline results in an unfamiliar distortion of these vessels arteriographically. Depending on the side of the mass effect, the thalamostriate-internal cerebral vein complex will have either an infinity (infinity) or a W configuration. Because these configurations appear frequently, recognition and understanding of them aid in the interpretation of cerebral arteriograms.