Ultrasonography (US) is an essential imaging method for the identification and evaluation of liver lesions. Using newer techniques such as contrast-enhanced US (CEUS), experienced operators are able to achieve liver tumor detection rates similar to that of computed tomography or magnetic resonance imaging scanning. US techniques that are useful in liver assessment may include B-mode US, Doppler imaging, CEUS, elastography, and endoscopic US. The healthy liver has a homogeneous parenchyma with a high water content, and is an excellent medium for the propagation of ultrasound waves. US imaging can be used to distinguish several diseases of the liver, including hepatitis, cirrhosis, infectious processes, metabolic and vascular disorders, and liver tumors. For patients with cirrhosis, US is important in the evaluation of liver disease and the monitoring of new liver cancers. Liver abscesses, fungal infections, cysts, and other focal lesions exhibit distinct features on US that may be used in diagnosis and assessment, including changes in echogenicity, blood flow patterns, and contrast uptake. US may be used to identify several types of liver tumors, including benign (noncancerous) tumors, malignant tumors, and other types of liver masses. Clinically relevant benign masses that may be identified using US include liver hemangiomas, focal nodular hyperplasia, hepatocellular adenoma, and benign cysts. Malignant tumors may develop in patients with liver cirrhosis (eg, hepatocellular carcinoma), or they may reflect cancer that has metastasized to the liver from other parts of the body (eg, metastatic breast cancer or colorectal cancer). Recognizing characteristic changes in vascularization and contrast uptake is often critical in distinguishing benign from malignant tumor masses.
After reading this article, the participant should be able to:
- Describe the basic organization of the liver, including major segments, arteries, and veins.
- List ultrasonography (US) techniques that are useful for the diagnosis of liver diseases.
- Summarize the application of US techniques to the evaluation and management of liver lesions associated with infectious processes, benign and malignant tumors, and liver trauma.
Categories: Ultrasound/Sonography, Professional Development/Patient Care Quality