Contrast-Enhanced Ultrasound Imaging for Diagnosing Recurrent Renal Cell Carcinoma (RCC) Post Ablation

This study is testing whether a contrast-enhanced ultrasound (CEUS) scan can accurately detect if kidney cancer (renal cell carcinoma) has come back after ablation treatment (such as cryotherapy or microwave therapy), potentially as an alternative to CT or MRI scans. **You may be eligible if...** - You previously had cryotherapy or microwave ablation for kidney cancer - You have had, or are scheduled to have, a contrast-enhanced MRI or CT scan to monitor for cancer recurrence within 4 weeks of the ultrasound study - You are 18 years or older and medically stable - If you are a woman of childbearing age, you have a negative pregnancy test **You may NOT be eligible if...** - You are medically unstable or seriously/terminally ill - You have a known allergy to the ultrasound contrast agent (Lumason) - Your medical course is unpredictable Talk to your doctor to see if this trial is right for you.