An Introduction to Contrast-Enhanced Ultrasound for Nephrologists.

Contrast-enhanced ultrasound (CEUS) is an emerging technology with no known nephrotoxicity. CEUS has been utilized in cardiac and abdominal imaging for decades in Asia and Europe and has recently received greater attention in the United States with its approval for characterization of indeterminate liver lesions. Emerging data suggest that CEUS has potential as a diagnostic imaging tool among individuals who have contraindications to CT and MRI. Few nephrologists are aware of CEUS and even fewer are aware of its potential applications among individuals with kidney disease. This review introduces CEUS to the nephrology community and provides a basic overview of CEUS technology. Knowledge of the applications, advantages, and disadvantages of CEUS provides the framework for nephrologists to make informed decisions regarding this emerging imaging test in appropriate circumstances. This review focuses on the use of CEUS for the characterization of indeterminate kidney lesions and summarizes the most recent data, some of which specifically includes patients with chronic kidney disease (CKD). The results demonstrate that CEUS has high sensitivity and moderate specificity for detecting malignancy in indeterminate kidney lesions among individuals with and without CKD. In conclusion, CEUS is an emerging imaging technique that may have clinically useful applications for detecting malignant kidney lesions, specifically in patients with CKD. However, most of the current data come from small, single-center studies, and larger, multicenter studies are needed.