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

Abstract

To quantitatively evaluate blood-brain barrier changes in ischemic stroke patients using dynamic contrast-enhanced (DCE) MRI. 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. 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. 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.