How is a FibroScan (Fibrosis Scan) report interpreted?

FibroScan Report Interpretation

FibroScan measures liver stiffness in kilopascals (kPa) to stage fibrosis non-invasively, with specific thresholds guiding clinical decisions: values >7.0 kPa indicate significant fibrosis (≥F2), values >12.5 kPa indicate cirrhosis (F4), and these cutoffs should be interpreted alongside clinical context, laboratory data, and the underlying liver disease etiology. 1

Technical Validity Requirements

Before interpreting any FibroScan result, verify technical adequacy 2, 3:

• ≥10 successful measurements must be obtained 4, 2
• Success rate ≥60% is required 4, 2
• Interquartile range (IQR) <30% of the median value 4, 2
• Results failing these criteria are unreliable and should be repeated 2

Fibrosis Stage Interpretation by kPa Values

For Chronic Hepatitis B (Most Recent WHO 2024 Guidelines)

Significant Fibrosis (≥F2): 1

• >7.0 kPa identifies most adults with significant fibrosis
• Sensitivity: 75.1%, Specificity: 79.3% 1
• These patients are priority for antiviral treatment 1

Cirrhosis (F4): 1

• >12.5 kPa identifies most adults with cirrhosis
• Sensitivity: 82.6%, Specificity: 89.0% 1
• Requires urgent hepatology referral and hepatocellular carcinoma screening 2

For Non-Alcoholic Fatty Liver Disease (NAFLD)

Fibrosis staging thresholds: 4, 3

• <8.0 kPa: Minimal/no fibrosis (F0-F1) - repeat surveillance in 2-3 years 4, 3
• >7.0 kPa: Significant fibrosis (≥F2) 3
• 8.0-12.0 kPa: Advanced fibrosis (F3) 3
• >12.0 kPa: Cirrhosis (F4) - refer to hepatology for additional testing 4, 3

For Alcohol-Related Liver Disease

Advanced fibrosis exclusion: 1, 2

• <8.0 kPa reliably rules out advanced fibrosis 1, 2
• Higher cutoffs indicate need for specialist referral 1

Clinical Context Modifiers

FibroScan measures liver stiffness, which reflects fibrosis plus inflammation plus portal hypertension - not fibrosis alone 5, 6. Values must be interpreted considering:

Factors That Falsely Elevate Readings

• Recent alcohol consumption - ideally test after 2 weeks of abstinence 2
• Active hepatic inflammation - elevated transaminases can increase stiffness 5, 6
• Acute hepatitis - defer testing until resolution 4, 3
• Extrahepatic biliary obstruction - causes falsely elevated values 4, 3
• Congestive hepatopathy - portal hypertension increases stiffness independent of fibrosis 5

Technical Limitations Causing Test Failure

FibroScan has approximately 5% failure rate, primarily in 4, 3, 6:

• Severe obesity - excessive subcutaneous fat prevents adequate signal
• Ascites - fluid interferes with measurement
• Narrow intercostal spaces - inadequate acoustic window

Integration with Laboratory Tests

Sequential Testing Strategy (Recommended Approach)

Step 1: Calculate FIB-4 score first using routine labs (AST, ALT, platelets, age) 4, 2, 3

Step 2: Interpret FIB-4 results 4, 3:

• FIB-4 <1.3 (<2.0 if age >65): Advanced fibrosis excluded, repeat in 3-5 years
• FIB-4 1.3-2.67: Indeterminate - proceed to FibroScan
• FIB-4 >2.67: High risk - refer to hepatology regardless of FibroScan

Step 3: Use FibroScan for indeterminate FIB-4 scores 4, 3

This sequential approach is more accurate than either test alone 4, 3

Complementary Scores for Hepatitis B

APRI score thresholds (WHO 2024): 1

• >0.5: Significant fibrosis (≥F2)
• >1.0: Cirrhosis (F4)

When FibroScan and APRI are discordant, the higher stage should guide management decisions given the consequences of missing advanced disease 1

Risk Stratification for Disease Progression

Patients with borderline values (7-8 kPa) require more frequent monitoring if they have 3:

• Age >35-40 years 3
• Male gender 3
• Metabolic syndrome components (obesity, diabetes, hypertension) 3
• Elevated liver enzymes despite mild fibrosis 3
• Ongoing alcohol consumption 3
• Viral hepatitis co-infection 3

These patients should be monitored every 6-12 months rather than every 2-3 years 3

Common Interpretation Pitfalls

Pitfall 1: Assuming normal ALT excludes significant fibrosis 3

• 18-43% of patients with normal ALT have significant fibrosis on biopsy, particularly those >35-40 years old 3

Pitfall 2: Using FibroScan alone without calculating simple scores first 2

• Always calculate FIB-4 or APRI before ordering FibroScan to optimize resource utilization 2

Pitfall 3: Ignoring the controlled attenuation parameter (CAP) 4

• CAP measures hepatic steatosis and provides additional prognostic information 4

Pitfall 4: Not recognizing that FibroScan only measures stiffness 2

• Cannot diagnose the underlying cause of liver disease or exclude alternative diagnoses 2

Pitfall 5: Testing during active inflammation 2

• Defer FibroScan until transaminases normalize or stabilize 2

Follow-Up Intervals Based on Results

Low-risk patients (<7.0-8.0 kPa): 4, 3

• Repeat FibroScan every 2-3 years if risk factors persist
• Extend to 3-5 years if no ongoing risk factors

Intermediate-risk patients (7.0-12.0 kPa): 3

• Repeat annually to monitor progression
• More frequent (every 6-12 months) if multiple risk factors present

High-risk patients (>12.5 kPa): 2

• Immediate hepatology referral
• Initiate hepatocellular carcinoma surveillance
• Consider liver biopsy if management would change 3

Prognostic Value

FibroScan provides critical prognostic information beyond diagnosis 2, 5:

• Values >12.5 kPa correlate with increased liver-related morbidity and mortality 4
• Can assess portal hypertension severity 5, 6
• Useful for prioritizing follow-up urgency in resource-limited settings 2