Perfusion-MRI is a Poor Indicator of Hemodynamic Compromise in Vertebrobasilar Disease in the VERiTAS Study

Dynamic susceptibility perfusion MR imaging (DSC MRP) has been used to assess changes in cerebral perfusion attributable to vascular stenosis or occlusion that may predict stroke risk. However, DSC MRP is not validated for identifying hemodynamic compromise in the posterior circulation. We investigated the clinical utility of DSC MRP in vertebrobasilar (VB) atherosclerotic disease in the observational VERiTAS study.

VERiTAS enrolled patients with symptomatic ≥50% VB stenosis/occlusion. Posterior circulation hemodynamic status was designated as low or normal based on large vessel flow measured using quantitative magnetic resonance angiography (QMRA) and was predictive of future stroke risk. In this study, DSC MRP conducted concurrently with QMRA was used to evaluate posterior circulation perfusion. The primary outcome was the mean transit time (MTT) and relative cerebral blood volume (rCBV) in the posterior circulation normalized to the anterior circulation, compared between patients with low and normal blood flow as determined on QMRA.

Twenty-six subjects had 47 DSC MRP studies for review. There was no statistically or clinically significant difference in the rCBV ratio (1.02 vs. .96 P = .89), or MTT ratio (1.04 vs. 1.04 P = .96) relative to normal or low VB territory flow.

In this study, we did not find that DSC MRP adequately distinguished between patients with low or normal flow status based on large-vessel flow measurements.