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

Abstract

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.gov NCT00715533, 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 K^trans 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 K^trans 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 K^trans values decreased over time with a clear interaction of timepoint and stroke/mirror side (p < 0.001). Median stroke K^trans 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 K^trans 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.