Inclusion Criteria:

- Any adult patient who is planned or scheduled for surgical excision or biopsy of a
solid or complex cystic renal mass would be eligible for the study

- Histology of the renal mass must be unknown at the time of enrollment

- Patients who have renal masses that are evident on conventional US imaging

- Patients will have a correlative abdominal CT and/or MRI

Exclusion Criteria:

- Patients with any history of cardiac shunts.

- Patients with history of pulmonary hypertension or unstable cardiopulmonary
conditions, including patients on mechanical ventilation.

- Patients without peripheral IV access

- Pregnant patients and children

- Patients with any known contrast allergies, allergy to perflutren, or any components
of Definity or microbubble contrast

- Patients who have renal masses that are not evident on conventional US imaging