Ultrasound Findings in Acute Hepatitis

Primary Sonographic Features

The American College of Radiology recommends abdominal ultrasound as the first-line imaging modality for acute hepatitis, which typically shows diffuse hepatic hypoechogenicity, increased portal vein wall thickness, and the characteristic "starry sky" appearance 1
Diffuse hepatic hypoechogenicity is the hallmark finding, reflecting acute parenchymal inflammation and edema 1
Increased thickness of portal vein walls appears as prominent echogenic structures throughout the liver 1
The "starry sky" appearance manifests as conspicuous portal triads standing out against the background of dark, edematous liver parenchyma 1
Hepatomegaly is present in 52.9% of patients during various phases of acute hepatitis 2
Gallbladder wall thickening occurs in 75.3% of patients with acute hepatitis 2

Perihepatic fluid may be present 2, 4
Splenomegaly occurs in 56.5% of cases 2
Periportal edema can be visualized, though this is better appreciated on cross-sectional imaging 2

The American College of Radiology suggests adding Duplex Doppler to routine grayscale ultrasound when ischemic hepatitis is suspected to assess vascular patency 1
Ischemic liver injury can progress to liver failure with high mortality 2
Look for hepatic arterial or portal venous occlusion in patients with shock liver or hypotensive episodes 2

Small hepatoduodenal lymphadenopathy is present in 98.8% of cases 2
Perihepatic fat infiltration occurs in 76.5% of patients 2
Pelvic fluid collection is found in 56.5% of cases 2
Ascites indicates more severe hepatic dysfunction 2
Gallbladder wall thickness >5.2 mm is an independent predictor of severe hepatitis and prolonged cholestasis 2

Perform grayscale ultrasound first to evaluate hepatic echogenicity, portal vein walls, liver size/contour, and gallbladder 1
Add Duplex Doppler immediately if clinical context suggests ischemic injury (shock, hypotension, cardiac disease) 1
Measure gallbladder wall thickness as values >5.2 mm predict severe disease 2
Document all associated findings including splenomegaly, ascites, and lymphadenopathy 2
Escalate to MRI with contrast if findings are equivocal, fulminant hepatitis is suspected, or vascular pathology needs better characterization 3, 4