To evaluate the reproducibility of cerebrovascular reactivity (CVR) measurements acquired in children using magnetic resonance imaging (MRI) in combination with a computer-controlled carbon dioxide (CO2) stimulus.Materials and Methods:
Ten healthy children (age 16.1 ± 1.6 years) underwent CVR imaging on a 3T scanner using a blood-oxygen level-dependent (BOLD) MRI sequence. Targeted hypercapnia was induced during imaging with a CO2 gas challenge delivered using a specialized gas sequencer (RespirAct). A total of four BOLD scans were performed over 2 separate days to test within-day and between-day consistency of the data. CVR values were computed by correlating the relative change in BOLD signal in response to the CO2 stimulus delivered to the each subject.Results:
Intraclass correlation coefficients (ICCs) of within-day values show highly reproducible measures in both the gray matter (ICC = 0.857, P < 0.001) and white matter (ICC = 0.895, P < 0.001). Relatively lower between-day reproducibility was observed in both the gray matter (ICC = 0.776, P = 0.001) and white matter (ICC = 0.719, P = 0.004).Conclusion:
Using a computer-controlled CO2 stimulus, we have demonstrated the reliability of BOLD-CVR measurements in pediatric subjects. Within-day and between-day metrics of reproducibility were comparable to adult data. J. Magn. Reson. Imaging 2016;43:1191–1195.