Contrast-enhanced ultrasound in diagnosis and characterization of focal hepatic lesions

Table 1 Indications for the use of contrast-enhanced ultrasonography

Patients for whom the ultrasonography without contrast, computed tomography, magnetic resonance imaging or cytology is not conclusive

Evaluation of lesions before percutaneous treatment to have a first image to compare after the procedure if necessary

Guidance of the needle or the probe during percutaneous treatment

Immediate evaluation of the lesion after percutaneous treatment to detect viable areas[24]

Follow-up of patients with liver lesions treated by percutaneous ethanol injection or radiofrequency ablation

Detection of liver tumors and study of its microcirculation

Evaluation of organ perfusion

Study of macrocirculation

Improvement of sensibility and specificity during intraoperative sonography

Table 2 Typical enhanced-ultrasound patterns in benign focal liver lesions

	Arterial phase	Portal phase	Late phase
Hemangioma	Peripheral nodular hyperenhancement with centripetal progression	Slow centripetal filling. The lesion becomes iso or hyperenhanced	Iso or hyperenhanced
Focal nodular hyperplasia	Hyperenhanced in the center of the lesion (central vessel) with fast centrifugal filling due to radial vascular branches: “wheel sign”	Iso or hyperenhanced	Iso or hyperenhanced. Sometimes the central scar can be seen
Adenoma	Highly hyperenhanced with complete filling and fast wash-out. No radial branches	Iso or hyperenhanced	Iso or hyperenhanced
Simple cist	No enhancement	No enhancement	No enhancement
Regenerative nodule	Isoenhanced	Isoenhanced	Isoenhanced
Focal fatty accumulation	Isoenhanced	Isoenhanced	Isoenhanced

Table 3 Typical enhanced-ultrasound pattern in malignant focal liver lesions

	Arterial phase	Portal phase	Late phase
Hepatocellular carcinoma	Hyperenhanced due to its arterial vascularization	Fast wash-out leaving an iso or hypoenhanced lesion	Hypoenhanced
Cholangiocarcinoma	Hyperenhanced in the border	Iso or hypoenhanced	Hypoenhanced
Hypervascular metastasis	Hyperenhanced, usually starting in the margin: ring sign	Iso or hypoenhanced	Hypoenhanced
Hypovascular metastasis	Hypoenhanced	Hypoenhanced	Hypoenhanced