Focal Low and Global High Permeability Predict the Possibility, Risk, and Location of Hemorrhagic Transformation following Intra-Arterial Thrombolysis Therapy in Acute Stroke

Y Li,W Zhang,M Wintermark,Y Xia,H Chen,G Zhu,Y Zhang,Z Su,J Tu,A Jackson,N Liu,J Hu,B Wu

doi:10.3174/ajnr.a5287

Abstract

The contrast volume transfer coefficient (Ktrans), which reflects blood-brain barrier permeability, is influenced by circulation and measurement conditions. We hypothesized that focal low BBB permeability values can predict the spatial distribution of hemorrhagic transformation and global high BBB permeability values can predict the likelihood of hemorrhagic transformation. We retrospectively enrolled 106 patients with hemispheric stroke who received intra-arterial thrombolytic treatment. Ktrans maps were obtained with first-pass perfusion CT data. The Ktrans values at the region level, obtained with the Alberta Stroke Program Early CT Score system, were compared to determine the differences between the hemorrhagic transformation and nonhemorrhagic transformation regions. The Ktrans values of the whole ischemic region based on baseline perfusion CT were obtained as a variable to hemorrhagic transformation possibility at the global level. Forty-eight (45.3%) patients had hemorrhagic transformation, and 21 (19.8%) had symptomatic intracranial hemorrhage. At the region level, there were 82 ROIs with hemorrhagic transformation and parenchymal hemorrhage with a mean Ktrans, 0.5 ± 0.5/min, which was significantly lower than that in the nonhemorrhagic transformation regions (P < .01). The mean Ktrans value of 615 nonhemorrhagic transformation ROIs was 0.7 ± 0.6/min. At the global level, there was a significant difference (P = .01) between the mean Ktrans values of patients with symptomatic intracranial hemorrhage (1.3 ± 0.9) and those without symptomatic intracranial hemorrhage (0.8 ± 0.4). Only a high Ktrans value at the global level could predict the occurrence of symptomatic intracranial hemorrhage (P < .01; OR = 5.04; 95% CI, 2.01-12.65). Global high Ktrans values can predict the likelihood of hemorrhagic transformation or symptomatic intracranial hemorrhage at the patient level, whereas focal low Ktrans values can predict the spatial distributions of hemorrhagic transformation at the region level.

Highlights

BACKGROUND AND PURPOSEThe contrast volume transfer coefficient (Ktrans), which reflects blood-brain barrier permeability, is influenced by circulation and measurement conditions
A high Ktrans value at the global level could predict the occurrence of symptomatic intracranial hemorrhage (P Ͻ .01; OR ϭ 5.04; 95% CI, 2.01–12.65)
Global high Ktrans values can predict the likelihood of hemorrhagic transformation or symptomatic intracranial hemorrhage at the patient level, whereas focal low Ktrans values can predict the spatial distributions of hemorrhagic transformation at the region level

Summary

Methods

We retrospectively enrolled 106 patients with hemispheric stroke who received intra-arterial thrombolytic treatment. The Ktrans values of the whole ischemic region based on baseline perfusion CT were obtained as a variable to hemorrhagic transformation possibility at the global level. We retrospectively enrolled consecutive patients who were admitted to these institutions with signs and symptoms suggesting hemispheric stroke, from January 2011 to January 2014, who met the following inclusion criteria: National Institutes of Health Stroke Scale scores on admission of 4 –22; completion of a stroke CT imaging work-up including noncontrast CT, CT angiography, and PCT on admission; no high density that suggested intracranial hemorrhage on baseline noncontrast CT; treatment with IAT, with Ͻ12 hours from symptom onset to IAT completion; coagulation function normal before IAT; no anticoagulation or antiplatelet agent given within 24 hours after IAT; and MR imaging performed on the third day after therapy.

Results

Discussion

Conclusion