Contrast-enhanced ultrasound and microcirculation: efficiency through dynamics--current developments

Ultrasound is often the first imaging modality used in the diagnosis of abdominal vascular as well as parenchymal organ pathologies. Contrast-enhanced ultrasound (CEUS) enables the dynamic assessment and quantification of microvascularisation up to capillary perfusion. Current clinical applications of CEUS are mainly in detection and characterization of lesions, particularly benign and malignant hepatic and renal lesions, based on differences between lesion and organ perfusion. Multifrequency high-resolution transducers are being increasingly used, including intra-operatively. Dynamic 3D techniques and ultrasound image fusion with CT or MRI may assist the diagnosis and therapy control after interventional procedures. Our own studies have demonstrated the excellent diagnostic performance of CEUS with perfusion-analysis in the characterization of hepatic and renal lesions as well as the assessment of tissue transplant macro- and microvascularisation. CEUS opens up new possibilities in the characterization of the microvasculature with perfusion analysis, even during the course of interventions, thereby providing new possibilities for modified therapeutic strategies. In this review, the different new ultrasound techniques with their potential applications are described and illustrated.