DCE-MRI blood–brain barrier assessment in acute ischemic stroke

Objective: To quantitatively evaluate blood–brain barrier changes in ischemic stroke patients using dynamic contrast-enhanced (DCE) MRI. Methods: We examined 54 stroke patients (clinicaltrials.govNCT00715533, NCT02077582) in a 3T MRI scanner within 48 hours after symptom onset. Twenty-eight patients had a follow-up examination on day 5–7. DCE T1 mapping and Patlak analysis were employed to assess BBB permeability changes. Results: Median stroke Ktrans values (0.7 × 10⁻³ min⁻¹ [interquartile range (IQR) 0.4–1.8] × 10⁻³ min⁻¹) were more than 3-fold higher compared to median mirror Ktrans values (0.2 × 10⁻³ min⁻¹, IQR 0.1–0.7 × 10⁻³ min⁻¹, p < 0.001) and further increased at follow-up (n = 28, 2.3 × 10⁻³ min⁻¹, IQR 0.8–4.6 × 10⁻³ min⁻¹, p < 0.001). By contrast, mirror Ktrans values decreased over time with a clear interaction of timepoint and stroke/mirror side (p < 0.001). Median stroke Ktrans values were 2.5 times lower than in hemorrhagic transformed regions (0.7 vs 1.8 × 10⁻³ min⁻¹; p = 0.055). There was no association between stroke Ktrans values and the delay from symptom onset to baseline examination, age, and presence of hyperintense acute reperfusion marker. Conclusion: BBB in acute stroke patients can be successfully assessed quantitatively. The decrease of BBB permeability in unaffected regions at follow-up may be an indicator of global BBB leakage even in vessel territories remote from the index infarct.