The VERITAS study aims to determine if among patients with symptomatic vertebrobasilar disease, those with distal blood flow compromise are at higher risk of subsequent posterior circulation stroke than those with normal flow.  Determination of blood flow compromise will be based on a noninvasive magnetic resonance (MR) imaging combining quantitative MRA and MR perfusion imaging.  The study is a 5 year prospective observational study funded by NIH, which will be conducted at 5 sites in the U.S. and one in Canada enrolling a total of 80 patients with confirmed vertebrobasilar stenosisgreater than or equal50% or occlusion.

Study is closed to enrollment and in data analysis.