Inclusion Criteria:  Glioma Cohort  Adult (> 18 years old) patients with newly diagnosed or recurrent high grade glioma with newly confirmed pathology (within 1 month) Able to provide informed consent No contraindications to MRI with gadolinium contrast or 18F-FAZA PET  Cervical Cohort  Adult (>18 years old) female with newly diagnosed cervical cancer Able to provide informed consent Receiving surgery, radiotherapy or chemotherapy No contraindication to MRI with gadolinium contrast or 18F-FAZA PET  Exclusion Criteria:  Glioma Cohort  Prior nephrectomy or planned nephrectomy. Prior brain radiation within 30 days. Pregnant or lactating women: Pregnant women are excluded from this study because the effects of 18F-FAZA in pregnancy are not known. A urine or serum pregnancy test will be performed before enrollment after informed consent is obtained. The pregnancy test is part of SOC before imaging. Lactation should be suspended for at least two days following the administration of 18F-FAZA to the mother, because of the unknown but potential risk for adverse events in nursing infants secondary to administration of the radionuclide to a lactating woman. Subjects with contraindications to the use of 18F-FAZA including confirmed allergy. Patients with a body weight of 400 pounds or more, or a BMI which precludes their entry into the bore of the PET-MRI scanner, because the findings will probably be compromised in image quality with PET-MRI. Any additional medical condition, serious concurrent illness, or other extenuating circumstance that, in the opinion of the investigator may significantly interfere with study compliance.  Cervical Cohort  Prior nephrectomy or planned nephrectomy. Pregnant or lactating women: Pregnant women are excluded from this study because the effects of 18F-FAZA in pregnancy are not known. A urine or serum pregnancy test will be performed before enrollment after informed consent is obtained. The pregnancy test is part of SOC before imaging. Lactation should be suspended for at least two days following the administration of 18F-FAZA to the mother, because of the unknown but potential risk for adverse events in nursing infants secondary to administration of the radionuclide to a lactating woman. Subjects with contraindications to the use of 18F-FAZA including confirmed allergy. Patients with a body weight of 400 pounds or more, or a BMI which precludes their entry into the bore of the PET-MRI scanner, because the findings will probably be compromised in image quality with PET-MRI and MRI. Any additional medical condition, serious concurrent illness, or other extenuating circumstance that, in the opinion of the investigator may significantly interfere with study compliance.