This is an observational study to compare the utility of the novel aMRI approach in human brain to the standard of care imaging approach for diagnosing and assessing glioma. Tumor cells have altered metabolism compared to normal cells.This makes metabolic activity imaging useful for diagnosing and assessing neurological disease. However, current options for metabolic activity imaging are limited. Metabolic activity imaging is primarily conducted using positron emission tomography (PET) with a radioactive tracer called fludeoxyglucose F-18 (¹⁸FDG). A PET scan is a procedure in which a small amount of radioactive glucose (¹⁸FDG) is injected into a vein, and a scanner is used to make detailed, computerized pictures of areas inside the body where the glucose is taken up. PET imaging is very expensive and is usually much less available than other imaging techniques such as magnetic resonance imaging (MRI). MRI uses radiofrequency waves and a strong magnetic field to provide clear and detailed pictures of internal organs and tissues. While MRI is more available than PET, it isn't as useful in evaluating metabolic activity. Unlike standard MRI, the aMRI approach uses new ways of analyzing MRI images that provides information about tumor cell metabolic activity. Via direct comparison with a standard metabolic imaging approach, ¹⁸FDG PET, this clinical trial will assess the validity of aMRI as a metabolic imaging approach for evaluating neurological disease in patients with glioma.