Inclusion Criteria:  Patient must have a brain mass consistent with a primary brain tumor or metastatic brain tumor able to give consent and willingness to participate in this study.  Exclusion Criteria:  presence of any ferromagnetic implant (cardiac pacemakers, aneurysm clip, etc.) pregnancy claustrophobia or anxiety disorder history of vertigo persons with diabetes mellitus (self-report or HbA1C >= 6.5%) Sickle cell disease persons taking prescription medicine for hypertension blood iron deficiency (Hb concentration < 11 g/dL or Hct < 32%) If volunteering for MRI: history of kidney disease and/or eGFR < 60. Middle-ear disorder double vision Seizure disorder Multiple myeloma Solid organ transplant History of severe hepatic disease/liver transplant/pending liver transplant