When should a patient with a history of fatty liver disease (FLD) noted on ultrasound (US) undergo a fibroscan?

Fibroscan Timing for Patients with Fatty Liver Disease on Ultrasound

Patients with fatty liver disease noted on ultrasound should undergo baseline fibroscan (transient elastography) immediately upon diagnosis to assess for advanced fibrosis, with follow-up fibroscan annually if abnormalities are detected. 1

Initial Assessment Algorithm

1. Immediate Baseline Fibroscan:

   • All patients with fatty liver on ultrasound should undergo baseline liver elastography (fibroscan) to identify advanced liver disease 1
   • This is especially important since ultrasound cannot reliably distinguish simple steatosis from steatohepatitis or fibrosis 2

2. Risk Stratification (to be performed concurrently):

   • Calculate FIB-4 score to determine fibrosis risk:
     • FIB-4 < 1.3: Low risk
     • FIB-4 1.3-2.67: Indeterminate risk
     • FIB-4 > 2.67: High risk 1
   • For patients ≥65 years old, use modified FIB-4 cutoffs 1

3. Fibroscan Results Interpretation:

   • LSM < 8 kPa: Low risk - repeat fibroscan in 2-3 years
   • LSM 8-12 kPa: Indeterminate risk - refer to hepatologist with re-evaluation in 2-3 years
   • LSM > 12 kPa: High risk - immediate referral to hepatologist 1

Follow-up Schedule

• Low Risk Patients (LSM < 8 kPa):

  • Repeat fibroscan every 2-3 years unless clinical circumstances change 1
  • Continue annual liver function tests and physical examination 1

• Intermediate/High Risk Patients (LSM ≥ 8 kPa or abnormal liver tests):

  • Annual fibroscan to monitor for disease progression 1
  • More frequent monitoring of liver function tests (every 6 months) 1

Special Considerations

• Obesity: Use XL probe for patients with BMI ≥30 kg/m² as standard probes may have higher failure rates 3, 4

• Technical Limitations:

  • Ensure adequate quality measurements (IQR/Med ratio <30% for reliable results) 4
  • Be aware that inflammation can falsely elevate liver stiffness measurements 4

• Diagnostic Accuracy:

  • Fibroscan has high sensitivity (87%) and specificity (91%) for diagnosing cirrhosis 2
  • Controlled Attenuation Parameter (CAP) can quantify steatosis degree with cutoff of 276 dB/m for moderate-severe steatosis 2

Clinical Pitfalls to Avoid

1. Delayed Assessment: Many patients with NAFLD are diagnosed late, often at the stage of decompensated cirrhosis. Early fibroscan can identify those at risk before disease progression 5.

2. Relying Only on Ultrasound: Ultrasound alone has limited sensitivity (53-65%) for mild steatosis and cannot reliably detect fibrosis 1.

3. Ignoring Normal Liver Enzymes: Significant fibrosis can exist despite normal ALT levels; do not delay fibroscan based solely on normal liver function tests 5.

4. Missing High-Risk Patients: Patients with type 2 diabetes have higher risk of significant fibrosis and should be prioritized for early fibroscan evaluation 1.

By following this structured approach to fibroscan timing, clinicians can identify patients with advanced fibrosis early, potentially reducing morbidity and mortality associated with progression to cirrhosis and its complications.