Focal liver lesions in cirrhosis: Role of contrast-enhanced ultrasonography

Table 1 Characteristics of contrast agents SonoVue and Sonazoid for contrast-enhanced ultrasound

Agent	SonoVue	Sonazoid
Gas	Sulfurhexafluoride (SF6)	Perfluorobutane (C4F10)
Envelope	Monolayer of phospholipid (DSPC, DPPG-Na)	Monolayer of phospholipid (Hydrogenated egg phosphatidyl serine Na)
MI	Low MI (< 0.1)	Intermediate MI (> 0.2)
Mean size	1.5-2.5 µm	2.3-2.9 µm
Distribution after injection	Pure blood pool agent	Blood pool agent with uptake by hepatic Kupffer cells after 1 min by injection

DSPC: 1,2-distearoyl-sn-glycero-3-phosphocholine; DPPG-Na: 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-glycerol sodium; MI: Mechanical index.

Table 2 Imaging enhancement pattern of cirrhotic nodules and malignant focal liver lesions on Contrast-enhanced ultrasound

Lesion	Arterial phase	Portal venous phase	Late phase	Post-vascular phase
RN	Hypo-enhance	Iso-enhance	Iso-enhance	Iso-enhance
DN	Hypo-enhance or partial hyper-enhanced within lesion (early-HCC)	Iso-enhance	Iso-enhance	Iso-enhance
HCC	Hyper-enhance	Hypo-enhance or iso-enhance	Hypo-enhance or iso-enhance1	Hypo-enhance (mild and late washout) or iso-enhance1
ICC	Rim-enhance or Hyper-enhance with early washout (< 60 seconds)	Hypo-enhance	Hypo-enhance	Hypo-enhance
Metastasis	Rim-enhance or Hyper-enhance with early washout (< 60 seconds)	Hypo-enhance	Hypo-enhance	Hypo-enhance

¹Well differentiated hepatocellular carcinoma. RN: Regenerative nodules; DN: Dysplastic nodules; HCC: Hepatocellular carcinoma; ICC: Intrahepatic cholangiocarcinoma.

Table 3 Recommendations contrast-enhanced ultrasound in cirrhotic liver

Recommendations	Notes
Characterization FLLs found in patients with liver cirrhosis to establish a diagnosis of malignancy	CT or MR imaging is required for a complete staging
In nodules not suitable for biopsy	When CT or MR are inconclusive
Selection of FLLs with different contrast pattern in a cirrhotic liver to be biopsied
Monitoring changes in enhancement patterns in FLLs in cirrhotic liver requiring follow-up
Guiding percutaneous biopsies to increase the diagnostic outcome	To compare to B-mode US

FLLs: Focal liver lesions; CT: Computed tomography; MR: Magnetic resonance; US: Ultrasounds.

Table 4 Imaging enhancement pattern of benign focal liver lesions on contrast-enhanced ultrasound

Lesion	Arterial phase	Portal venous phase	Late phase	Post-vascular phase
Hepatic cysts	Non-enhance	Non-enhance	Non-enhance	Non-enhance
Cystic hydatid disease	Non-enhance cysts and septa	Non-enhance cysts and septa	Non-enhance cysts and septa	Non-enhance cysts and septa
Abscess	Rim-enhance with enhanced septa; no central enhancement	Rim-enhance with enhanced septa; no central enhancement	Hypo-enhance rim; no central enhancement	Hypo-enhance rim; no central enhancement
Hemangioma	Peripheral, discontinuous and globular hyper-enhance	Peripheral, globular iso enhance and fill-in	Iso-enhance or hypo-enhance	Iso-enhance or hypo-enhance
FNH	Hyper-enhance from the center to peripheral region spoke-wheel vascularity	Hyper-enhance with/without un-enhanced central scar	Iso-enhance or hyper-enhance with/without un-enhanced central scar	Iso-enhance or hypo-enhance
HA	Hyper-enhance	Iso-enhance	Iso-enhance	Iso-enhance or hypo-enhance
Pseudo lesions	Hyper-enhance	Hyper-enhance or iso-enhance	Iso-enhance	Iso-enhance

FNH: Focal nodular hyperplasia; HA: Hepatocellular adenoma.