Background/Question: A significant number of children who present to the Emergency Department (ED) with headache or migraine undergo head imaging with Computed Tomography (CT) or Magnetic Resonance Imaging (MRI). However, there is relatively low yield in imaging neurologically normal patients based on prior studies. The goal of this study is to describe the utilization of head CT or MRI among pediatric ED patients with headache and migraine. The investigators plan to evaluate clinical and examination characteristics of these patients, and use this information to develop a clinical decision rule to help providers predict the risk of finding an abnormality that affects patient treatment.