Magnetic Resonance Perfusion Tracks 133 Xe Cerebral Blood Flow Changes After Carotid Stenting

Abstract

To compare magnetic resonance (MR) perfusion to gold-standard cerebral blood flow (CBF) determined by intra-arterial (133)Xe washout method. Eight patients with high-grade carotid stenoses underwent bolus-tracking MR perfusion and intra-arterial (133)Xe washout before and after carotid stenting. MR perfusion was compared with 133Xe-CBF values using Pearson linear correlation analysis. We observed a mean 37+/-38% increase in 133Xe-CBF and a mean 19+/-27% increase in relative CBF (rCBF) by MR perfusion immediately after stent placement. Relative (percent) changes in MR-rCBF showed a close and linear correlation to those seen in 133Xe-CBF (r=0.91; R2=0.84; P=0.002). There was a trend for MR perfusion to underestimate change in CBF at higher relative changes in flow. Bolus-tracking MR perfusion correlates with 133Xe-CBF in estimating postprocedural increases in blood flow but may underestimate the magnitude of the change with higher relative changes.