Perfusion Magnetic Resonance Imaging in Diagnosing Patients With Kidney Tumors

Inclusion Criteria:

* Patients must be able to read, understand, and voluntarily sign an informed consent document
* For patients with organ confined renal tumors to be enrolled, the renal mass must be \>= 1 cm in diameter on computed tomography (CT) or magnetic resonance imaging (MRI) and can be any clinical stage T1a-T4 (non-metastatic); a histologic diagnosis is not required for enrollment; the primary imaging site would be kidney
* For patients with metastatic renal tumors to be enrolled, a histologic diagnosis of renal cell carcinoma must exist and any burden of disease \>= 1 cm by CT or MRI is acceptable; the metastatic sites may be kidney, intra-abdominal (such as liver), brain, bone, or lymph nodes; lung lesions are NOT eligible because of the motion artifact caused by respiration
* Patients with metastatic disease may have received prior nephrectomy and/or prior systemic therapy (no limit on number); their baseline pMRI would be performed prior to starting a new treatment
* Negative pregnancy test if female of child-bearing age
* Able to undergo contrast enhanced MRI

Exclusion Criteria:

* Severe concurrent disease, infection, or medical co-morbidity that, in the judgment of the investigator, would make the patient inappropriate for enrollment
* Severe renal function impairment (estimated glomerular filtration rate \[eGFR\] \< 45 mL/min/1.73 m\^2) would make the patient inappropriate for enrollment due to the increased risk of nephrogenic systemic fibrosis (NSF) with higher dose of IV gadolinium-based contrast agents (GBCA) administration
* Women who are pregnant or breastfeeding
* Subjects who are unable to tolerate or are not eligible for MR imaging (claustrophobia, metal implantable devices such as pacemaker, aneurysm clips, etc)
* Subjects with established allergy to IV GBCA