Hyperpolarized Carbon C 13 Pyruvate Magnetic Resonance Spectroscopic Imaging in Detecting Lactate and Bicarbonate in Participants With Central Nervous System Tumors

Inclusion Criteria:

* Patients with a known diagnosis of central nervous system (CNS) malignancy, including metastases, with known enhancement on magnetic resonance (MR) who are otherwise eligible to undergo MRI
* Glomerular filtration rate (GFR) \> 30 ml/min
* No allergy to gadolinium
* Ability to understand and the willingness to sign a written informed consent document

Exclusion Criteria:

* Refusal to have an IV placed for injection
* Acute major illness (e.g., unstable angina, etc.) or other condition that makes participation unsafe, per the investigator?s judgement
* Total bilirubin \> 1.5 x upper limit of normal (ULN)
* Aspartate aminotransferase (AST)/alanine aminotransferase (ALT) \> 2.5 x ULN
* Gamma-glutamyltransferase (GGT) \> 2.5 x ULN
* Pregnant or breast-feeding
* Cardiovascular risk, including:

* Poorly controlled hypertension, defined as either systolic \> 170 or diastolic \> 110
* Congestive heart failure
* Myocardial infarction within the past year
* QT prolongation, defined as pretreatment corrected QT interval (QTc) \> 440 msec in males or \> 460 msec in females