Optimizing US for HCC surveillance

Abstract

Ultrasound is the primary imaging modality used for surveillance of patients at risk for HCC. In 2017, the American College of Radiology Liver Imaging Reporting and Data Systems (ACR LI-RADS) introduced US LI-RADS to standardize the performance, interpretation, and reporting of US for HCC surveillance, with the algorithm recently updated as LI-RADS US Surveillance v2024. The American Association for the Study of Liver Diseases (AASLD) recommends reporting both the examination-level LI-RADS US Category as well as the US Visualization Score. The US Category conveys the overall findings of the exam and primarily determines follow up recommendations. The US Visualization Score conveys the expected sensitivity of the test and stratifies patients into appropriate surveillance pathways. One of the goals of routine surveillance is the detection of HCC at an early, potentially curable stage. Therefore, optimizing US technique is of critical importance. Increasing North American and worldwide utilization of LI-RADS US Surveillance, which includes technical recommendations, through education and outreach will undoubtedly benefit patients undergoing US HCC surveillance.

Fig. 1

ACR LI-RADS US Surveillance v2024 Algorithm, reproduced with permission from ACR

Fig. 2

Visualization scores. a VIS-A, no limitations. Transverse grayscale US image in a 56-year-old patient with cardiac cirrhosis/congestive hepatopathy. b VIS-B, moderate limitations. Transverse grayscale US image in a 42-year-old patient with ethanol cirrhosis shows moderate parenchymal heterogeneity. c VIS-C, severe limitations. Transverse grayscale image in a 59-year-old patient with steatosis and metabolic dysfunction-associated steatohepatitis (MASH) cirrhosis shows poor penetration of the liver and complete obscuration of the diaphragm

Fig. 3

Visualization score improves in outpatient setting in a 60-year-old male with alcoholic cirrhosis. a Sagittal grayscale US image of the liver shows rib shadows and ascites, with no suspicious observation noted. The patient was hospitalized for decompensated cirrhosis and was unable to change positions or suspend respiration. b Sagittal grayscale US image of the liver performed a few months later in the outpatient setting shows a 2.3 cm hypoechoic solid nodule (arrow and in calipers), categorized as US-3 positive. This was characterized as LR-5 on subsequent MRI (not shown)

Fig. 4

Change in visualization score on follow-up in a 33-year-old male with metabolic dysfunction-associated steatohepatitis (MASH) versus alcoholic cirrhosis. a and b. Sagittal and transverse grayscale US images show minimal liver parenchyma due to rib shadows in a and bowel gas in b. Follow up grayscale US 3 months later shows no limitations and adequate visualization of the liver. Over 50% of patients with VIS—C scores improve on follow up 10

Fig. 5

Isoechoic HCC. Transverse grayscale US image in a 58-year-old patient with hepatitis C cirrhosis shows an isoechoic HCC. The hypoechoic halo and refractive edge shadows (arrows) around the margins of the observation make it stand out against the background of the cirrhotic liver

Fig. 6.

55-year-old female with ethanol cirrhosis and a 15 cm right lobe infiltrative cholangiocarcinoma not originally appreciated on US. Note that an infiltrative HCC could have a similar appearance. a Sagittal US image of the right lobe of the liver shows a large area of parenchymal distortion (arrows) with areas of refractive shadowing. b Sagittal US image of the left lobe of the liver, included for comparison, shows cirrhosis without parenchymal distortion. c Axial contrast enhanced arterial phase CT shows large area of heterogeneous enhancement (arrows) in the right lobe of the liver, corresponding to biopsy proven infiltrative cholangiocarcinoma. The right portal vein was not discretely visualized, presumably due to tumor in vein (not shown)

Fig. 7

Infiltrative HCC and tumor in vein in a 62-year-old male with acute liver failure, presenting for urgent liver transplant evaluation. a Transverse grayscale US image shows a large area of parenchymal distortion in the right lobe of the liver (arrows), initially attributed to cirrhosis. The interpreting radiologist recognized the lack of a normal portal vein and requested additional images. b Sagittal grayscale US image of the porta hepatis using a larger field of view and the gallbladder (G) (filled with sludge) as a window, shows an expanded, thrombosed portal vein (arrows) with echogenic walls. c. Spectral Doppler image of the portal vein shows low resistance arterial flow diagnostic of tumor in vein

Fig. 8

Liver mass initially not seen on routine abdominal US performed in a 63-year-old male with metabolic dysfunction-associated steatohepatitis (MASH) and F3 fibrosis. a Transverse grayscale US image right lobe of the liver shows a peripheral hypoechoic region (arrows), only visualized on retrospective review of the images, that may correspond to the observation detected in b. b Patient returned for US elastography 3 weeks later, and sonographer placed patient in a decubitus position. Sagittal and transverse grayscale US dual screen image of the liver shows a 4.6 cm solid hypoechoic mass (arrows). This case underscores the need to examine the liver’s periphery, which can be enhanced by placing the patient in a decubitus position, suspending respiration, and using intercostal and subcostal scanning. c and d Axial contrast-enhanced MRI of the abdomen in the arterial (c) and delayed (d) phases show arterial phase hyperenhancement of the observation with ‘washout’ and enhancing ‘capsule’, representing HCC

Fig. 9

Cine sweeps clarify questionable finding on static grayscale images in a 63-year-old male with advanced fibrosis undergoing HCC surveillance. a Transverse grayscale ultrasound image shows a possible hypoechoic area (arrow) adjacent to right portal vein. b Select transverse grayscale image from a transverse right lobe cine sweep confirms a 2 cm solid hypoechoic nodule (arrow) that was categorized as LR-M on subsequent CEUS