Hyperperfusion and blood-brain barrier disruption beyond the diffusion-restricted infarct one day after successful mechanical thrombectomy.

Background and purpose: Patterns of the cerebral microcirculatory response with changes in the blood brain barrier and perfusion in patients with stroke and a large vessel occlusion are still unclear. We combined dynamic contrast enhancement (DCE) permeability and DSC perfusion MRI to detect such patterns beyond the borders of the diffusion-restricted infarct core after successful recanalization.

Materials and methods: Combined DCE permeability and DSC perfusion MRI were performed prospectively in patients within 24h after successful mechanical recanalization of acute middle cerebral artery occlusion. Perfusion alterations were visually assessed on CBF and CBV maps, blood-brain-barrier disruptions (BBBD) on ktrans-maps and quantitatively evaluated with an ipsi-to contralateral ratio. Additionally, logistic regression analysis was performed for favorable early clinical outcome (NIHSS ≤2 at discharge).

Results: N=38 patients were included in the study. Subtle hyperperfusion beyond the DWI-lesion was present in 13/38 patients (34%) on CBF-maps and elevated CBV in 15/38 patients (39%). In these patients, the ratios between ipsi-and contralateral white matter CBF (p=0.01) and CBV (p<0.01) were elevated compared to patients with normal readings. Subtle, but visually and quantitatively elevated ktrans-values outside the DWI-lesion were observed in 7/38 patients (18%). None of these perfusion alterations were related to clinical outcome.

Conclusions: Combined DCE-permeability and DSC-perfusion imaging is feasible in patients 24 hours after successful thrombectomy and reveals subtle hyperperfusion and BBBD occuring frequently beyond the diffusion restricted infarct core.

Abbreviations: DCE = Dynamic Contrast Enhancement, BBBD = blood brain barrier disruption, MT = Mechanical thrombectomy.