ABSTRACT
Ultrasound microbubble contrast agents were originally developed to improve or rescue Doppler studies where there is low volume=slow £ow or the signals are weak because of attenuation by overlying tissues.Microbubbles are composed of air or complex gas particles of less than 10 mm in diameter which are stable enough to cross capillary beds and provide safe, e¡ective systemic acoustic enhancement when given intravenously. Recent technological advances have produced novel imaging modes which exploit the nonlinear behavior of microbubble contrast agents and have dramatically extended the clinical and research applications of ultrasound. Ultrasound ( US) is commonly the ¢rst imaging modality used in the diagnosis and assessment of both focal and di¡use liver disease. However, US is less sensitive than computed tomography (CT) and magnetic resonance (MR) in the detection of metastatic liver disease, and all imaging modalities are inaccurate in the diagnosis of cirrhosis. The advent of US microbubbles imaged with contrast-speci¢c modes promises to improve the sensitivity
and speci¢city of ultrasound in the detection and characterization of focal liver lesions to rival that of other cross-sectional modalities. This chapter reviews the current and potential applications of ultrasound contrast agents in the diagnosis of focal and di¡use liver disease.
