Contrast-Enhanced Ultrasound (CEUS)

Contrast-enhanced ultrasound (CEUS) imaging is a widely used medical imaging technique combining ultrasound and ultrasound contrast agents (UCAs) for clinical decision-making. UCAs are gas microbubbles coated with a biocompatible shell; they stay intravascular and act as resonant scatterers producing echoes with characteristic harmonics that can be used for real-time evaluation of the vascular architecture and contrast enhancement patterns in regions of interest. In urology, CEUS has generally been used for the diagnosis of prostate cancer (PCa) through improved targeting for prostate biopsy and evaluation of small renal masses, especially when contrast-enhanced imaging with computed tomography (CT) or magnetic resonance imaging (MRI) is contraindicated. Current clinical applications of CEUS have expanded to include interventional and postinterventional treatment evaluation and monitoring of focal therapy for benign and malignant urological conditions. CEUS can provide early and convincing evidence on the local effect and extent of the ablated zone and possibly also the identification of residual tumor. Recognizing the important evolving role of CEUS in the assessment of various urological conditions, greater level of standardization and consistency is needed to facilitate high-quality integration in daily clinical practice. Further investigation and refinement will be necessary to define the clinical role of CEUS as stand-alone tool, or in a multiparametric fashion with other emerging ultrasound modalities such as sonoelastography or micro-ultrasound.