The Consistence of Dynamic Contrast‐Enhanced MRI and Filter‐Exchange Imaging in Measuring Water Exchange Across the Blood–Brain Barrier in High‐Grade Glioma

Abstract

BackgroundWater exchange across blood–brain barrier (BBB) (WEXBBB) is an emerging biomarker of BBB dysfunction with potential applications in many brain diseases. Several MRI methods have been proposed to measure WEXBBB, but evidence remains scarce whether different methods can produce comparable WEXBBB.PurposeTo explore whether dynamic contrast‐enhanced (DCE)‐MRI and vascular water exchange imaging (VEXI) could produce comparable WEXBBB in high‐grade glioma (HGG) patients.Study TypeProspective cross‐sectional.Subjects13 HGG patients (58.4 ± 9.4 years, 9 females, 4 WHO III and 9 WHO IV).Field Strength/SequenceA 3 T, spoiled gradient‐recalled‐echo DCE‐MRI and VEXI containing two pulsed‐gradient spin‐echo blocks separated by a mixing block.AssessmentsThe enhanced tumor and contralateral normal‐appearing white matter (cNAWM) volume‐of‐interests (VOIs) were drew by two neuroradiologists. And whole‐brain NAWM and normal‐appearing gray matter (NAGM) without tumor‐affected regions were segmented by automated segmentation algorithm in FSL.Statistical TestsStudent's t‐test was used to evaluate parameters difference between cNAWM and tumor, NAGM and NAWM, respectively. The correlation between vascular water efflux rate constant (kbo) from DCE‐MRI and apparent exchange rate across BBB (AXRBBB) from VEXI was evaluated by Pearson correlation. P < 0.05 was considered statistically significant.ResultsCompared with cNAWM, both kbo and AXRBBB were significantly reduced in tumor (kbo = 3.50 ± 1.18 sec−1 vs. 1.03 ± 0.75 sec−1; AXRBBB = 3.54 ± 1.11 sec−1 vs. 1.94 ± 1.04 sec−1). Both kbo and AXRBBB showed significantly higher values in NAWM than NAGM (kbo = 3.50 ± 0.59 sec−1 vs. 2.10 ± 0.56 sec−1; AXRBBB = 3.35 ± 0.77 sec−1 vs. 2.07 ± 0.52 sec−1). The VOI‐averaged kbo and AXRBBB were also linearly correlated in tumor, NAWM, and NAGM (r = 0.59).Data ConclusionDCE‐MRI and VEXI showed comparable and correlated WEXBBB in HGG patients, suggesting that the consistence and reliability of these two MRI methods in measuring WEXBBB.Evidence Level2.Technical EfficacyStage 1.