Hepatocellular carcinoma (HCC) is the most common primary liver cancer, and nearly all of it arises in livers that are already diseased: cirrhosis from hepatitis B or C, alcohol, or metabolic-associated fatty liver disease. Surveillance ultrasound exists to catch HCC while it's still small enough to cure. For many cirrhotic patients, you are the screening test.

Who Gets Surveillance, and How Often

Major guidelines (AASLD, EASL) recommend surveillance ultrasound, with or without serum AFP, every 6 months for:

Adults with cirrhosis of any cause who would be candidates for treatment
Certain patients with chronic hepatitis B even without cirrhosis, based on age, sex, ancestry, and family history

The 6-month interval reflects how fast HCC typically grows. Annual scans let too many tumors outgrow curative treatment.

Scanning Technique

The cirrhotic liver is one of the hardest organs to scan well: shrunken, coarse, nodular, and often tucked high under the ribs.

Fasting for 4–6 hours improves the window and distends the gallbladder
Curvilinear probe, typically 2–5 MHz; drop the frequency for large or fatty patients
Subcostal and intercostal sweeps. The intercostal approach often rescues the right lobe and dome.
Left lateral decubitus and deep-inspiration breath holds to bring the liver down
Sweep every segment systematically, including the dome, caudate, and lateral left lobe
Use harmonics and adjust the focal zone as you go deeper

Also assess:

Liver surface: nodular contour (a high-frequency linear probe on the anterior surface helps)
Portal vein: patency, flow direction (hepatopetal or hepatofugal), velocity
Spleen size and ascites as signs of portal hypertension
Any varices or a recanalized paraumbilical vein

What HCC Can Look Like

There's no single "HCC look," which is why any new nodule matters.

Small HCC (under ~2 cm): most often hypoechoic
Larger HCC: heterogeneous, mosaic pattern, sometimes hyperechoic (fat or necrosis)
Peripheral hypoechoic halo, the pseudocapsule
Arterial hypervascularity within the nodule on color Doppler

HCC: arterial hypervascularity within a hepatic nodule on color DopplerImage: R. Badea and Simona Ioanitescu, CC BY 3.0, via Wikimedia Commons

Early HCC arising in a dysplastic nodule: a hypoechoic lesion with internal vascularityImage: R. Badea and Simona Ioanitescu, CC BY 3.0, via Wikimedia Commons

Remember: ultrasound doesn't diagnose HCC. Its job is to find observations that need multiphase CT or MRI. Your report categorizes the finding, and imaging with contrast characterizes it.

LI-RADS Ultrasound Categories

The ACR's LI-RADS ultrasound surveillance algorithm standardizes what an exam result means and what happens next.

Category	Meaning	Typical next step
US-1 Negative	No observation, or only definitely benign findings (e.g., a simple cyst)	Repeat surveillance in 6 months
US-2 Subthreshold	Observation under 10 mm, not definitely benign	Repeat ultrasound in about 3 months
US-3 Positive	Observation 10 mm or larger, not definitely benign, or a new thrombus in a vein	Multiphase contrast-enhanced CT or MRI

The radiologist assigns the category, but your measurements and images are what it's built on, so measure every observation in its longest dimension and image it in two planes.

Visualization Scores

Every surveillance report also includes how well you could see the liver. That tells the team how much to trust a "negative" exam.

Score	Meaning
VIS-A	No or minimal limitations; small lesions unlikely to be missed
VIS-B	Moderate limitations that may obscure small masses
VIS-C	Severe limitations; focal lesions could be missed

Common causes of VIS-B or VIS-C are a heterogeneous or coarse cirrhotic liver, steatosis with beam attenuation, obesity, and high liver position with rib shadowing. Be honest here. A VIS-C exam reported as reassuring is a real patient-safety problem, and repeated VIS-C exams can prompt the team to choose a different surveillance method. Note why visualization was limited.

Portal Vein Thrombus: Bland or Tumor?

A new portal vein thrombus in a cirrhotic patient is a positive (US-3) finding.

Feature	Bland thrombus	Tumor in vein
Vein	Usually not expanded	Often expanded
Color Doppler within thrombus	No flow	Internal flow
Spectral Doppler	n/a	Arterial waveform inside the thrombus
Adjacent liver	Often unremarkable	May have an associated mass

Put spectral Doppler inside the thrombus, not just in the patent lumen. Arterial signal within a thrombus is one of the most important findings you can make on this exam.

What to Document

Liver size, contour, and echotexture
Each observation: location (segment), size, echogenicity, margins, color Doppler
Comparison with prior exams. New or growing is the key word.
Portal vein patency, direction, velocity, and any thrombus with internal Doppler
Spleen size, ascites, and visible varices
Visualization score with the reason for any limitation

Example wording to suggest to the interpreting physician:

"New 14 mm hypoechoic observation in segment VI with internal color Doppler flow, not seen on the exam from 6 months ago. Portal vein patent with hepatopetal flow. Visualization: moderate limitation from coarse parenchyma."

Red Flags: Escalate Promptly

Tumor in vein: portal or hepatic vein thrombus with internal arterial flow
A new or growing observation of 10 mm or more
New hepatofugal portal flow or new large-volume ascites
Multiple new nodules compared with the prior exam

Bottom Line

A surveillance liver exam is only as good as its weakest window. Scan every segment, measure every observation, put Doppler inside any thrombus, and report your visualization honestly. Your job is to flag what needs CT or MRI, every six months, without fail.

SonoBuddy is a reference tool, not a diagnostic authority. LI-RADS categories are assigned by the interpreting physician.

HCC Surveillance Ultrasound: LI-RADS Categories and Visualization Scores