Contrast-enhanced ultrasound of hepatocellular carcinoma: where do we stand?

Abstract

Contrast-enhanced ultrasound (CEUS) represents a significant breakthrough in ultrasonography (US), and it is being increasingly used for the evaluation of focal liver lesions (FLLs). CEUS is unique in that it allows non-invasively assessment of liver perfusion in real time throughout the vascular phase, which has led to dramatic improvements in the diagnostic accuracy of US in the detection and characterization of FLLs, the choice of therapeutic procedures, and the evaluation of response. Currently, CEUS is included as a part of the suggested diagnostic work-up of FLLs, including in cirrhotic patients with hepatocellular carcinoma, resulting in better patient management and cost-effective delivery of therapy.

Keywords: Contrast-enhanced ultrasonography; Hepatocellular carcinoma; Liver; Liver cirrhosis; Ultrasonography; Ultrasound contrast media.

Fig. 1.. Regenerative nodule in a 72-year-old man with cirrhosis.

A. Oblique ascending left subcostal baseline image reveals a moderately heterogeneous lesion measuring 3 cm in the fourth hepatic segment (arrow). B. In an image obtained 22 seconds after sulfur hexafluoride injection (arterial phase), the lesion lacks contrast enhancement (arrow). C, D. The lesion appears consistently isoechoic with respect to the surrounding liver parenchyma throughout the remaining vascular phases.

Fig. 2.. Hepatocellular carcinoma in a 65-year-old woman with hepatitis C-related cirrhosis.

A. Oblique ascending right subcostal baseline image reveals a mainly hyperechoic lesion surrounded by a peripheral hypoechoic rim measuring 4 cm in the sixth hepatic segment (calipers). B. The lesion appears markedly hypervascular during the arterial phase (arrow). C, D. It is not appreciable 83 seconds after sulfur hexafluoride injection (C), and shows clear-cut washout at 240 seconds (arrow) (D).

Fig. 3.. Hepatocellular carcinoma in a 53-year-old man.

A. A magnetic resonance image obtained during the hepatic arterial phase reveals a substantially unenhancing lesion in the fifth segment, measuring 1.5 cm (arrow). B, C. On magnetic resonance images obtained at same level during the portal venous (B) and the hepatocellular-specific (C) phases, the lesion appears hypointense (arrows). D-F. On contrast-enhanced ultrasonography, the same lesion is hypervascular on the image acquired during the arterial phase (arrow), is not evident during the extended portal-venous phase, but shows clear-cut washout (arrow) 300 seconds after sulfur hexafluoride injection (F).

Fig. 4.. Well-differentiated hepatocellular carcinoma in a 58-year-old man.

A, B. A right intercostal baseline image reveals a hypoechoic lesion measuring 1.5 cm in the fifth hepatic segment (calipers) (A), with some small arterial vessels inside the lesion in the pulsed Doppler evaluation (B). C. The lesion appears markedly hypervascular 25 seconds after sulfur hexafluoride injection (arrow). D. The lesion is not evident during the late phase (240 seconds).

Fig. 5.. Intrahepatic cholangiocarcinoma in a 73-year-old man.

A. An oblique ascending right subcostal baseline image reveals a highly heterogenous lesion with ill-defined margins measuring 6.5 cm in the eighth hepatic segment (arrow). B, C. During the arterial phase, the mass appears heterogeneously vascularized (arrow) (B) with rapid (43 seconds after sulfur hexafluoride injection) washout (arrow) (C). D. Arterial phase contrast-enhanced computed tomography shows a hypoattenuating subcapsular mass (white arrow) associated with moderate bile duct dilatation in the context (black arrow). E, F. The lesion shows progressive enhancement during the portal-venous (E) and the late (F) phases (arrows).

Fig. 6.. Hepatocellular carcinoma in a 70-year-old man with hepatitis C-related cirrhosis.

A, B. An oblique ascending right subcostal baseline image reveals a markedly inhomogeneous lesion measuring 9.7 cm in the seventh hepatic segment (calipers) (A) with a vascular signal in its context (B). C. During the arterial phase, the mass is highly hypervascular (arrow). D. During the extended portal-venous phase, a slight hyperechoic peripheral rim is evident, suggesting a pseudocapsule (white arrow) with necrotic areas inside the mass (black arrow). E. The lesion shows a washout sign, appearing hypoechoic with respect to the surrounding liver parenchyma 5 minutes after the start of the hexafluoride injection (arrow).

Fig. 7.. Liver hemangioma in a 48-year-old woman with hepatitis C-related cirrhosis.

A. Baseline image shows a homogeneously hyperechoic lesion measuring 1.7 cm in the seventh hepatic segment (arrow). B. In the arterial phase, peripheral globular enhancement is evident (arrow); C, D. The lesion presents progressive centripetal fill-in in the extended portalvenous phase (arrow), complete 3 minutes after the start of the sulfur hexafluoride injection.

Fig. 8.. Contrast Enhanced Ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS) algorithm.

CEUS Li-RADS v2017 Core (2017) with permission of American College of Radiology [59].

Fig. 9.. Complete response after radiofrequency ablation of hepatocellular carcinoma in a 58-year-old woman.

A, B. An oblique ascending right subcostal baseline ultrasound image shows a 1.4-cm-sized inhomogeneous, mainly hyperechoic area in the sixth segment (calipers) (A) with no vascular signal on color Doppler (B). C. On contrast-enhanced ultrasonography in the arterial phase (30 seconds after sulfur hexafluoride injection), the lesion shows a lack of contrast enhancement (arrow).

Fig. 10.. Residual tumor after radiofrequency ablation of hepatocellular carcinoma.

A. An axial baseline image in a 54-yearold woman shows a 1.6-cm-sized slightly hyperechoic area in the fifth segment (arrow). B. Contrast-enhanced ultrasonography in the arterial phase (17 seconds after sulfur hexafluoride injection) shows a clear-cut area of eccentrically located hypervascular tissue around the treated area (arrow). C. Threedimensional i-Slice reconstruction better A B depicts the same finding in each slice (arrows).

Fig. 11.. Malignant portal thrombus in a 83-year-old man with hepatitis B-related liver cirrhosis.

A. An oblique ascending right subcostal baseline ultrasound image shows the lumen of the right branch of the portal vein filled with thrombus isoechoic to the adjacent liver parenchyma (arrows). B. On contrast-enhanced ultrasonography in the arterial phase (15 seconds after sulfur hexafluoride injection) the thrombus shows evident contrast enhancement (black arrow), whereas the left portal branch is still anechoic (white arrow). C. At 122 seconds after the injection, the thrombus shows mild washout (black arrow), whereas the left portal branch is normally perfused (white arrow).