When should a FibroScan (Fibrosis Scan) be performed in patients with liver disease?

When to Perform FibroScan in Liver Disease

FibroScan should be performed after initial risk stratification with simple blood tests (FIB-4 score) in patients with chronic liver disease, specifically when FIB-4 is ≥1.3 in NAFLD patients, immediately in patients with harmful alcohol use (≥35 units/week for women, ≥50 units/week for men), and in all patients with chronic hepatitis B or C to guide antiviral therapy decisions. 1, 2

Algorithmic Approach by Disease Category

Non-Alcoholic Fatty Liver Disease (NAFLD)

• First step: Calculate FIB-4 score using routine labs (AST, ALT, platelet count, age) in all adults with suspected NAFLD 2
• FibroScan indication: Order FibroScan when FIB-4 ≥1.3 (or ≥2.0 in patients aged ≥65 years) 1, 2
• Bypass FibroScan: Refer directly to hepatology if FIB-4 >3.25 or NAFLD Fibrosis Score >0.675, as these patients are already high-risk 2
• Low-risk patients: If FIB-4 <1.3, re-evaluate after 1-2 years in patients with prediabetes, type 2 diabetes, or ≥2 metabolic risk factors; re-evaluate after 2-3 years in NAFLD patients without diabetes 1

Chronic Hepatitis B (CHB)

• Gray zone patients: Perform FibroScan in patients with ALT levels 1-2 times the upper limit of normal to determine if antiviral therapy should be initiated 1
• High-risk patients: Order FibroScan in patients aged ≥30-40 years with ALT at upper limit of normal, or those with normal ALT but persistently high HBV DNA 1
• Treatment decision: Initiate antiviral therapy when FibroScan detects significant fibrosis 1

Chronic Hepatitis C (HCV)

• Staging indication: Use FibroScan for fibrosis staging to guide treatment decisions in all confirmed HCV patients 2
• Significant fibrosis threshold: FibroScan >7.0 kPa identifies significant fibrosis (≥F2) 2
• Cirrhosis threshold: FibroScan >12.5 kPa indicates cirrhosis and requires urgent hepatology referral and HCC screening 2

Alcohol-Related Liver Disease

• Immediate assessment: Perform FibroScan as first-line test in patients drinking at harmful levels (≥35 units/week for women, ≥50 units/week for men) without waiting for FIB-4 calculation 2, 3
• Rule-out threshold: FibroScan <8.0 kPa reliably rules out advanced fibrosis 2, 4
• Critical timing: Ideally perform after 2 weeks of abstinence, as recent alcohol consumption falsely elevates liver stiffness measurements 2, 3

Additional High-Risk Populations Requiring FibroScan

• Patients with metabolic risk factors (obesity, diabetes, metabolic syndrome) 2
• Patients with persistently elevated liver enzymes of unclear etiology 2
• Patients with multiple metabolic risk factors requiring risk stratification 1

Technical Requirements for Valid Results

A FibroScan result is only reliable when ALL three criteria are met: 2, 4

• ≥10 successful measurements obtained
• Success rate ≥60%
• Interquartile range <30% of median value

Interpretation Thresholds for Clinical Action

• <8.0 kPa: Rules out advanced fibrosis; repeat pathway in 3-5 years if risk factors remain 2, 4
• >7.0 kPa: Indicates significant fibrosis (≥F2) 2
• 8-12 kPa: Suggests advanced fibrosis; requires hepatology evaluation 4
• >12.5 kPa: Indicates cirrhosis; requires urgent hepatology referral and HCC screening 2, 4

Critical Pitfalls to Avoid

Patient Preparation Errors

• Fasting requirement: Patients must fast for at least 4 hours before examination, as food intake increases hepatic blood flow and falsely elevates readings 2, 4
• Timing with inflammation: Avoid FibroScan during active hepatitis or recent alcohol use (ideally test after 2 weeks of abstinence) 2, 3

Technical Limitations

• Obesity: FibroScan may fail in patients with BMI >28 kg/m² (though extra-large probe is now available) 2, 4
• Contraindications: Cannot be performed reliably in patients with ascites, narrow intercostal spaces, acute hepatitis, or extrahepatic biliary obstruction 2
• Failure rates: Range from 1.1-3.5% in Asian populations to 4.3-10.5% in Western populations 2

Interpretation Errors

• Confounding factors: Liver stiffness can be falsely elevated by edema, inflammation, extrahepatic cholestasis, passive congestion, and elevated AST from alcoholic steatohepatitis 2, 3
• Not a standalone test: FibroScan only measures stiffness, not inflammation or alternative diagnoses; do not rely on it alone to rule out other causes of liver disease 2

When NOT to Order FibroScan

• Very low risk: FIB-4 <1.3 in NAFLD patients without diabetes or metabolic risk factors (unless re-evaluation is due) 1, 2
• Already high risk: FIB-4 >3.25 or NFS >0.675 (refer directly to hepatology) 2
• Technical contraindications: Patients with ascites, acute hepatitis, or extrahepatic biliary obstruction 2

Superiority Over Other Modalities

FibroScan demonstrates superior diagnostic accuracy compared to CT scan and ultrasound: 4, 5

• AUROC of 0.859 for significant fibrosis, 0.887 for severe fibrosis, and 0.929 for cirrhosis 4
• Ultrasound alone is not efficient for assessing advancement of liver disease 5
• CT scan should only be used for HCC surveillance or assessing cirrhosis complications, not for fibrosis staging 4