Utility of Arterial Spin Labeling MRI in Pediatric Neuroimaging: A Pictorial Essay

Abstract

With advances in magnetic field strength, multichannel coils and parallel imaging, arterial spin labeling (ASL) magnetic resonance imaging (MRI) is now widely available for clinical use. There is a growing body of literature on the utility of ASL in a variety of pediatric diseases that feature alterations in blood flow as part of the pathophysiologic process. ASL can help discriminate high-grade tumors from low-grade tumors, and is especially useful to identify characteristic hyperperfusion seen in hemangioblastoma and choroid plexus tumors. In moyamoya, ASL coupled with acetazolamide challenge provides quantitative cerebral blow flow data that can inform decisions regarding revascularization surgery. In both migraine headaches and hypoxic ischemic injury (HII), there is early hypoperfusion on ASL imaging followed by hyperperfusion. Global or medial occipital hyperperfusion in the setting of HII is a poor prognostic factor. ASL can identify hypoperfusion in seizure foci, but is more useful for seizure localization with hyperperfusion in the acute setting. ASL perfusion imaging is a useful adjunct to conventional brain MRI in children, and should be applied in a wide variety of clinical scenarios.