What is a wavy liver?

Wavy Liver: Understanding the Radiological Finding

A wavy liver refers to an undulating or nodular liver surface appearance seen on imaging studies, particularly ultrasound, which is a characteristic morphological sign of cirrhosis. This finding represents the nodular regeneration and fibrotic changes that occur in advanced chronic liver disease 1.

Radiological Features of Wavy Liver

The wavy or nodular liver surface is one of several morphological changes that can be observed in cirrhosis:

• Surface nodularity: Particularly visible on the anterior surface of the left lobe 1
• Undulating contour: Irregular, wavy appearance of the liver surface
• Associated findings: Often accompanied by other signs of cirrhosis:
  • Atrophic right lobe with hypertrophied caudate lobe and lateral segment of left lobe 1
  • Atrophied medial segment of left lobe 1
  • Right hepatic posterior "notch" 1
  • Expanded gallbladder fossa 1
  • Narrow hepatic veins (right hepatic vein < 5 mm) 1
  • Enlarged caudate-to-right lobe ratio (modified ratio > 0.90) 1
  • Enlargement of the hilar periportal space (>10-mm thickness) 1

Diagnostic Significance

The wavy liver appearance is a valuable diagnostic sign with important implications:

1. Diagnostic value: While fairly good at diagnosing cirrhosis, this finding is subjective and typically present only in later stages of fibrosis 1

2. Best imaging modalities:

   • Ultrasound: High-frequency transducers can demonstrate subtle surface nodularity with good spatial resolution 1
   • CT and MRI: Can also show liver surface nodularity but may be less sensitive for subtle changes 1

3. Limitations:

   • These morphologic features are present only in advanced disease 1
   • They cannot reliably detect early or intermediate stages of fibrosis 1

Differential Diagnosis

When a wavy liver is observed, several conditions should be considered:

• Cirrhosis: The most common cause of wavy liver appearance
• Advanced fibrosis: From various etiologies including viral hepatitis, alcoholic liver disease, and non-alcoholic fatty liver disease
• Congestive hepatopathy: Can sometimes produce similar appearance due to passive congestion

Clinical Correlation

The finding of a wavy liver should prompt:

1. Assessment of liver function: Liver function tests to evaluate hepatic synthetic function
2. Evaluation for portal hypertension: Look for splenomegaly, ascites, and collateral vessels
3. Elastography consideration: More sensitive methods like transient elastography (FibroScan), shear wave elastography, or MR elastography can quantify the degree of fibrosis 1
4. Etiology investigation: Workup for underlying causes of chronic liver disease

Advanced Imaging Options

For more definitive assessment of liver fibrosis when a wavy liver is detected:

• Ultrasound elastography: Shows acceptable to outstanding accuracy for detecting advanced fibrosis and cirrhosis 1
• MR elastography: Currently the most accurate imaging modality for diagnosing and staging hepatic fibrosis 1
• Conventional ultrasound with Doppler: Can assess for signs of portal hypertension that often accompany advanced fibrosis 1

Clinical Pitfalls

1. Overreliance on morphology: Surface nodularity alone should not be the sole criterion for diagnosing cirrhosis
2. Missing early disease: Wavy liver is a late finding; absence does not exclude early fibrosis
3. Confounding factors: Obesity, ascites, and technical factors can limit visualization of liver surface

The wavy liver appearance represents the end result of progressive fibrosis and nodular regeneration, serving as an important radiological marker of advanced chronic liver disease that warrants comprehensive evaluation and management.