Contrast-Enhanced Hepatic Sonography

Abstract

Hepatic applications of sonography include evaluation of the gallbladder and bile ducts, assessment of patients with suspected portal hypertension, and evaluation of focal and diffuse parenchymal liver disease. Ultrasound imaging (US) is generally a reliable and accurate method to diagnose a variety of hepatic abnormalities; however, in some cases there is a need to improve sonography's sensitivity and specificity, particularly for the detection and characterization of hepatic masses. Recent clinical experience has shown that the addition of a US contrast agent can enhance sonography's diagnostic capabilities including improving assessments of hepatic blood flow and the detection and characterization of hepatic neoplasms. One intravenously administered US contrast agent is now available in the United States, but its approved indication is limited to echocardiographic applications. Additional agents that have more diagnostic applications are likely to become available. Contrast-enhanced sonography may play a significant role in the diagnosis and management of patients with suspected hepatic abnormalities. This article describes two generic types of US contrast agents—vascular agents and tissue-specific agents—and includes a review of recent published reports on clinical applications of contrast-enhanced hepatic sonography.

A Selective Review of Commonly Used Sonography-Guided Hyperthermic Ablative Technologies for Malignant Lesions of the Liver

“…For these reasons, contrast-enhanced sonography would LeVeque 125 be a useful addition to a protocol for ablative therapy; however, intravenous contrast agents in the United States are currently only approved for applications related to echocardiography. 17 Considering the variables and the myriad of options available to thermal ablative technology, there is no clear preference between microwave and radiofrequency technique for clinical use. 3 Each hyperthermic energy source is unique, must be matched to the particular application at hand, and is dependent on available tools, operator discretion, skill level, and preference.…”

Doppler Football

“…2 Spectral Doppler breaks the Doppler-shifted frequencies down into their individual frequency components and displays them against time; modern systems convert the frequency shifts into a velocity component, which is then displayed against time. 3,4 Because the majority of the Doppler effect frequencies generated in sonography are within the frequency range of human hearing, many Doppler units have the capability of presenting the Doppler shift frequencies audibly.…”