Renal imaging with ultrasound contrast: current status

The application of ultrasound contrast agents to the kidney is still in its infancy; however, there are several areas of great promise. Ultrasound contrast agents may replace CT in complex renal cyst evaluation and follow-up. Ultrasound contrast agents are likely to be clinically useful in the evaluation of the indeterminate small renal mass on CT or MR imaging. Another probable useful application is in renal artery stenosis. It also will likely become the first line of evaluation in pyelonephritis, and be useful in immediate assessment of residual tumor after radiofrequency ablation. Substantial additional work needs to be performed in large groups of patients to prove this currently optimistic outlook.