This feasibility study will evaluate how well hyperpolarized 13C pyruvate magnetic resonance imaging (MRI) scan works in predicting tumor aggressiveness in participants with renal tumors. Hyperpolarized 13C pyruvate is a non-radioactive substance with potential usage in the diagnostic imaging of tumors. Hyperpolarized 13C pyruvate MRI may help doctors determine non-invasively whether a kidney tumor is a benign tumor or cancer, and if cancer, how aggressive it is. This may help doctors and participants with renal tumors in the future to make better treatment decisions.

PRIMARY OBJECTIVES:

1. To investigate the association between HP 13C pyruvate-to-lactate conversion (peak lactate/pyruvate ratio, lactate /pyruvate AUC (area under the curve), the apparent rate constant (kPL) and renal tumor histology (benign renal tumors versus RCCs) and grade (low vs high grade in cases of RCCs).

SECONDARY OBJECTIVES:

1. To determine the reproducibility of HP 13C pyruvate MRI in participants who undergo an optional second HP 13C pyruvate MRI.
2. To investigate the association between HP 13 C pyruvate-to-lactate conversion and tumor growth rate in participants who are deemed clinically appropriate for active surveillance for their renal tumors.
3. To determine the safety of HP 13C pyruvate in renal tumor participants.

EXPLORATORY OBJECTIVES:

1. To investigate the association between HP markers (peak lactate/pyruvate, lactate /pyruvate AUC, kPL) and tissue-based markers including Lactate Dehydrogenase A (LDHA) expression and lactate dehydrogenase (LDH) activity, and Monocarboxylate transporter 4 (MCT4) expression on tumor tissues from surgical specimen or from biopsy.
2. To explore the correlation between HP 13C pyruvate-to-lactate conversion (peak lactate/pyruvate ratio, lactate/pyruvate AUC (area under the curve), the apparent rate constant kPL) and 13C urea tissue perfusion in the kidneys and renal tumors.

OUTLINE:

Participants receive HP 13C pyruvate intravenously (IV) or a combination of co-polarized 13C pyruvate and 13C, 15N2 Labeled urea (15N2) and then undergo MRI scan 1-2 minutes post injection

Participants may receive an optional second HP 13C pyruvate intravenously (IV) or a combination of hyperpolarized 13C pyruvate and 13C, 15N2 urea injection and undergo 13C pyruvate MRI scan 15 to 30 minutes following completion of the first scan during the same imaging session, or the participant can return for a separate visit within 1-2 weeks from the first MRI to receive the optional second scan.

After completion of study treatment, participants are followed up 30 minutes.

Inclusion Criteria:

1. Renal tumor measuring 1 cm and greater in diameter. To minimize any potential partial volume effects in this pilot study, the investigators have limited the lower size range of the tumor to 1 cm. The investigators will include all renal tumor measuring 1 cm and greater in diameter in this first study to facilitate obtaining tumors of a range of histology and grade.
2. The participant is being considered by the treating physician to have any of the following management options: partial or radical nephrectomy, ablation, or active surveillance for his/her renal tumor.
3. The participant is able and willing to comply with study procedures and provide signed and dated informed consent.
4. The participant is willing to undergo standard of care abdominal MRI in connection with the study exam.
5. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.

Exclusion Criteria:

1. Participants who because of age, general medical or psychiatric condition, or physiologic status cannot give valid informed consent.
2. Participants unwilling or unable to undergo magnetic resonance (MR) imaging, including patients with contra-indications to MR imaging, such as cardiac pacemakers or non-compatible intracranial vascular clips.
3. Any metallic implant or device that distorts local magnetic field and compromises the quality of MR imaging of the abdomen.
4. Prior focal therapy (i.e. ablation) for the renal tumor.
5. Poorly controlled hypertension, with blood pressure at study entry >160/100. The addition of anti-hypertensives to control blood pressure is allowed for eligibility determination.
6. Congestive heart failure or New York Heart Association (NYHA) status >= 2.