Characterizing pre- and post-operative cerebral blood flow and transit time in pediatric moyamoya patients using multi-delay ASL and DSC MRI.

Cerebral blood flow (CBF) and transit time are essential biomarkers for assessing brain health. While dynamic susceptibility contrast (DSC) MRI has been widely applied to measure these metrics, it is limited in the pediatric population due to the need for contrast agents. Arterial spin labeling is a non-invasive and quantitative MR modality, and multi-delay ASL can measure CBF and transit time simultaneously. Although multi-delay ASL has been used in adult neuroimaging studies, its application in children requires investigation. Moyamoya disease, a progressive steno-occlusive cerebrovascular disorder, often manifests in childhood. In this work, we present a cohort study that examines multi-delay ASL and DSC MRI to characterize vascular hemodynamics in 22 pediatric patients. We evaluate CBF and transit time in different brain regions before and after revascularization surgeries. Results show that revascularization significantly increased CBF by 24% and 7.6%, respectively, as measured by ASL and DSC; it also significantly decreased transit time by 12% and 15%, indicating improved hemodynamics and metabolism. ASL and DSC results also showed significantly positive correlations in all brain regions. Thus, revascularization improved hemodynamics in pediatric moyamoya patients and shows that multi-delay ASL can effectively characterize CBF and transit time in the pediatric population.