Permeability imaging as a predictor of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

Blood-brain barrier (BBB) dysfunction has been implicated in ischemic risk following aneurysmal subarachnoid hemorrhage (aSAH), but never directly imaged. We prospectively examined whether post-bleed day 4 dynamic contrast-enhanced magnetic resonance (DCE-MR) BBB permeability imaging could predict development of delayed cerebral ischemia (DCI). Global MR-derived BBB permeability ( Ktrans) was significantly higher in aSAH patients who subsequently developed DCI (five patients; 2.28 ± 0.09 × 10-3 min-1) compared to those who experienced radiographic vasospasm only (three patients; 1.85 ± 0.12 × 10-3 min-1; p < 0.05), or no vasospasm/ischemia (eight patients; 1.74 ± 0.07 × 10-3 min-1; p < 0.01). Ktrans > 2 × 10-3 min-1 predicted development of DCI (AUC = 0.98, 95% CI: 0.93-1). Global BBB dysfunction following aSAH is detectable with DCE-MR and predictive of ischemic risk.