What is the recommended use of FibroScan (transient elastography) in patients at risk of liver fibrosis, such as those with hepatitis B (HBV) or C (HCV), non-alcoholic fatty liver disease (NAFLD), obesity, diabetes, or metabolic syndrome?

Use of FibroScan in Liver Disease

FibroScan (transient elastography) should be used as a second-line test after initial risk stratification with FIB-4 in patients with NAFLD, metabolic syndrome, diabetes, or obesity, and as a first-line assessment in patients with chronic hepatitis B or C, or those with harmful alcohol use. 1

Algorithmic Approach to FibroScan Use

Step 1: Initial Risk Stratification

Calculate FIB-4 first in all patients with suspected liver disease using routine labs (AST, ALT, platelet count, age). 1, 2 This inexpensive point-of-care test should precede FibroScan in most cases to avoid unnecessary testing and costs.

• For NAFLD patients without diabetes or metabolic syndrome: If FIB-4 <1.3, repeat in 2-3 years without FibroScan 1
• For NAFLD patients with diabetes or ≥2 metabolic risk factors: If FIB-4 ≥1.3, proceed to FibroScan 1
• For patients ≥65 years old: Use FIB-4 cutoff of 2.0 instead of 1.3 to exclude advanced fibrosis 1
• For FIB-4 >2.67: Consider direct hepatology referral regardless of FibroScan results 1

Step 2: When to Order FibroScan

Proceed directly to FibroScan without FIB-4 in these populations:

• Chronic hepatitis B or C: All patients require FibroScan to guide antiviral therapy decisions 1, 2
• Harmful alcohol use: Patients drinking ≥35 units/week (women) or ≥50 units/week (men) 1, 2
• "Gray zone" hepatitis B patients: Those with ALT 1-2 times upper limit of normal to determine if antiviral therapy should be initiated 1

Use FibroScan after FIB-4 in these populations:

• NAFLD with indeterminate FIB-4 (1.3-2.67): Proceed to FibroScan for further risk stratification 1
• Type 2 diabetes with suspected NAFLD: Even with borderline FIB-4, as 69.2% have NASH and 41.0% have advanced fibrosis 2
• Metabolic syndrome (≥2 risk factors): Obesity, hypertension, dyslipidemia, prediabetes 1

Step 3: Patient Preparation

Patients must fast for at least 3-4 hours before FibroScan to avoid falsely elevated liver stiffness measurements. 2, 3 Food intake increases hepatic blood flow and can overestimate fibrosis stage, particularly problematic when measurements fall near clinical decision thresholds.

For alcohol-related liver disease, ideally perform FibroScan after 2 weeks of abstinence as recent alcohol consumption falsely elevates liver stiffness. 2

Step 4: Interpretation of Results

Technical validity requirements must be met:

• ≥10 successful measurements obtained 1, 2, 3
• Success rate ≥60% 1, 2
• Interquartile range (IQR) <30% of median value 1, 2

If these criteria are not met, the result is unreliable and should not guide clinical decisions. 2, 4

For NAFLD/Metabolic Syndrome:

• <8.0 kPa: Rules out advanced fibrosis with 93% sensitivity; repeat in 2-3 years if metabolic risk factors persist 1, 2, 3
• 8.0-12.0 kPa: Indeterminate risk; refer to hepatologist for monitoring and re-evaluation in 2-3 years 1
• >12.0 kPa: High risk for advanced fibrosis/cirrhosis; refer to hepatologist for consideration of liver biopsy or MR elastography 1
• ≥15 kPa: Highly suggestive of compensated advanced chronic liver disease (cACLD), especially if platelet count <150,000 1

For Chronic Hepatitis B or C:

• >7.0 kPa: Indicates significant fibrosis (≥F2) 2, 3
• >12.5 kPa: Indicates cirrhosis; initiate HCC surveillance and variceal screening 2, 3, 4

For Cirrhosis Surveillance:

• >20-25 kPa: Diagnoses clinically significant portal hypertension; requires endoscopic variceal screening per Baveno criteria 1, 2

Step 5: Follow-Up Intervals

Low-risk patients (FibroScan <8.0 kPa):

• Repeat FIB-4 and/or FibroScan in 2-3 years if metabolic risk factors persist 1
• Repeat in 3-5 years if risk factors are well-controlled 1, 2

Patients with NASH and/or fibrosis: Monitor annually 1

Patients with NASH cirrhosis: Monitor at 6-month intervals 1

Patients with previous advanced fibrosis/cirrhosis: Continue hepatological follow-up despite successful antiviral therapy or decrease in noninvasive test results 1

Critical Confounding Factors and Pitfalls

FibroScan results can be falsely elevated by:

• Active hepatic inflammation or acute hepatitis: Can produce falsely cirrhotic-range values 2, 3, 4
• Extrahepatic cholestasis or biliary obstruction: Falsely elevates stiffness 2, 3, 4
• Right heart failure or passive congestion: Increases liver stiffness independent of fibrosis 2, 4
• Recent food intake: Mandatory 3-4 hour fast 2, 3
• Recent alcohol use: Ideally test after 2 weeks abstinence 2

Technical limitations:

• Obesity (BMI >28 kg/m²): May require XL probe; failure rates 4.3-10.5% in Western populations 2, 4, 5
• Ascites: Cannot perform FibroScan reliably 2, 4
• Narrow intercostal spaces: May cause failed acquisition 2, 4

The most common error is performing FibroScan without adequate fasting, which leads to overestimation of fibrosis stage and inappropriate escalation of care. 2

When FibroScan Results Trigger Specialist Referral

Immediate hepatology referral indicated for:

• FibroScan >12.0-12.5 kPa suggesting advanced fibrosis/cirrhosis 1, 3
• FibroScan ≥15 kPa with platelet count <150,000 (highly suggestive of cACLD) 1
• FibroScan >20-25 kPa indicating clinically significant portal hypertension 1, 2
• Discordant results between FIB-4 and FibroScan requiring liver biopsy 1

Hepatology referral for monitoring:

• FibroScan 8.0-12.0 kPa (indeterminate risk) 1
• Chronic hepatitis B "gray zone" patients with FibroScan showing significant fibrosis 1

Special Populations

Type 2 diabetes patients warrant particular attention as they have high rates of NASH (69.2%) and advanced fibrosis (41.0%) even with borderline FIB-4 scores. 1, 2 Screening for diabetes is mandatory in all NAFLD patients using fasting glucose, HbA1c, or 75g OGTT in high-risk groups. 1

Patients with congenital bleeding disorders previously exposed to HBV/HCV should be screened for additional chronic liver damage risk factors and evaluated with FibroScan even if asymptomatic with normal liver tests. 1

Type 1 diabetes patients should only be screened for fibrosis if additional risk factors present (obesity, incidental steatosis, elevated aminotransferases), as NAFLD prevalence is much lower than in type 2 diabetes. 1