Pediatric brain tumors have diverse pathologic features and are often difficult to diagnose or grade using routine biopsy methods and conventional magnetic resonance (MR) imaging. Arterial Spin Labeling–MR imaging (ASL-MRI) is a non-invasive imaging sequence that maps blood flow distribution in tumors without the use of a contrast agent. ASL-MRI is routinely used in tumor diagnosis, surgical guidance and therapeutic monitoring of adult brain tumors. However, it has not been evaluated for use with pediatric brain tumors. Researchers at the Center for Childhood Cancer Research, including Amish C. Shah, MD, PhD, are evaluating ASL-MRI to diagnose, grade and predict clinical outcomes in response to specific therapies in low-grade gliomas and other pediatric brain tumors.