Clinical/methodical issue: Focal liver lesions are commonly seen during routine ultrasound examinations.
Standard radiological methods: With native ultrasound there are lesions that cannot be sufficiently characterized. In these cases additional imaging might be necessary.
Methodical innovations: With contrast-enhanced ultrasound (CEUS), focal liver lesions can be characterized with high diagnostic accuracy. After the ultrasound contrast agent has been injected into a peripheral vein, the examiner saves video loops of the arterial, portal venous and late contrast phases. Combing the findings of native and contrast-enhanced ultrasound allows not only assessment of the etiology as benign or malignant but also detailed characterization of the focal liver lesion in most cases.
Performance: Using CEUS, focal liver lesions can be characterized with a sensitivity of over 95% and a specificity of about 83%.
Achievements: The advantages of CEUS include that there is no radiation exposure and that the ultrasound contrast agent has no effects on the function of the liver, kidneys or the thyroid gland. The main limiting factors for CEUS are bowel gas and obesity of the patient.
Practical recommendations: CEUS can visualize micro- and macrovascularization of benign focal liver lesions in real time. It is a useful imaging modality in unclear cases.
Keywords: Focal nodular hyperplasia; Hemangioma; Liver cysts; Ultrasonography; Washout.