This clinical trial uses a type of imaging scan called magnetic resonance imaging (MRI) to study brain tumor biology in patients with glioblastoma that can be removed by surgery (resectable). Malignant gliomas are the second leading cause of cancer mortality in people under the age of 35 in the United States. Glioblastoma is a type of malignant glioma with very poor patient prognosis. There are currently only about 3 drugs approved by the Food and Drug Administration (FDA) for the treatment of glioblastoma, one of them being administration of bevacizumab, which is very expensive. It is the most widely used treatment for glioblastoma with dramatic results. However, previous clinical trials have not demonstrated an overall survival benefit across all patient populations with glioblastoma that has returned after treatment (recurrent). The study aims to identify which patients who will benefit from bevacizumab therapy by observing MRI images and corresponding imaging biomarkers.