Very Low Cerebral Blood Volume Predicts Parenchymal Hematoma in Acute Ischemic Stroke

Abstract

Background and Purpose— Parenchymal hematoma (PH) may worsen the outcome of patients with stroke. The aim of our study was to confirm the relationship between the volume of very low cerebral blood volume (CBV) and PH using a European multicenter database (I-KNOW). A secondary objective was to explore the impact of early reperfusion and recanalization. Methods— The volume of cerebral tissue with CBV ≤2.5th percentile of the normal hemisphere was calculated within the acute diffusion-weighted imaging lesion. Hemorrhagic transformation was assessed on day 2 MRI according to the European Cooperative Acute Stroke Study II criteria. Recanalization and reperfusion were assessed on 3-hour follow-up MRI. Results— Of the 110 patients, hemorrhagic transformation occurred in 59 patients, including 7 PH. In univariate analysis, the acute National Institutes of Health Stroke Scale score ( P =0.002), acute diffusion-weighted imaging lesion volume ( P =0.02), and thrombolysis ( P =0.03), but not very low CBV ( P =0.52), were associated with hemorrhagic transformation. The volume of very low CBV was the only predictor of PH ( P =0.007). Early reperfusion and recanalization had no influence on either hemorrhagic transformation or PH. Conclusion— Very low CBV was the only independent predictor of PH in patients with acute stroke.

Reperfusion Within 6 Hours Outperforms Recanalization in Predicting Penumbra Salvage, Lesion Growth, Final Infarct, and Clinical Outcome

“…During the entire cohort, median and percentage DWI lesion reversal volume were 5.4 mL (2.7-11.8) and 43% (22-72), respectively. Reperfused patients had a higher percentage of DWI lesion reversal than those without reperfusion: 68% (33-89) versus 24% (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31), respectively (P=0.002). No significant difference in volume of DWI lesion reversal was found between patients with or without reperfusion (P=0.14).…”

“…Several previously published reports are based on this cohort. [12][13][14][15] Inclusion criteria for I-KNOW were (1) NIHSS ≥4; (2) diffusionweighted imaging (DWI) and perfusion-weighted imaging (PWI) consistent with an acute anterior circulation ischemic stroke; and (3) admission MRI completed within 6 hours for patients treated with intravenous tPA, or within 12 hours for those managed without tPA. Patients with lacunar or posterior circulation stroke, unknown time of onset or intracerebral hemorrhage were excluded.…”

Predicting Collateral Status With Magnetic Resonance Perfusion Parameters

“…1 The present results are also supported by previous studies revealing that a severe, but not mild, perfusion delay 15 and low CBV are associated with hemorrhagic transformation, which is probably related to poor collaterals. 28 It was speculated that high Tmax values seen in hyperacute stroke indicate poor delayed collateral supply. Furthermore, regions with long arrival delays, even if relatively wellperfused, are the most at risk if perfusion pressure further declines.…”

Interaction of Recanalization, Intracerebral Hemorrhage, and Cerebral Edema After Intravenous Thrombolysis

“…Interaction of early reperfusion with other indices of severe ischemia (large diffusion weighted imaging volumes, 15 low cerebral blood volume on perfusion imaging, 16 or poor collaterals 17 ) has been reported for SICH after intravenous thrombolysis. The extent of vasogenic edema may also interact with ischemic core volume (>50% hypodensity on computed tomography (CT) was associated clinically with malignant brain edema 18 ) and in an animal model reperfusion of large volumes of severely ischemic tissue (cerebral blood flow [CBF] <40%) led to malignant edema.…”