What are the Fibroscan cutoff values for staging non‑alcoholic fatty liver disease (NAFLD) steatosis and fibrosis?

Fibroscan Cutoff Values for NAFLD Steatosis and Fibrosis

For NAFLD fibrosis staging, use liver stiffness measurement (LSM) <8.0 kPa to rule out advanced fibrosis and ≥12.0 kPa to rule in clinically significant fibrosis; for steatosis detection, use controlled attenuation parameter (CAP) values ≥275 dB/m to diagnose hepatic steatosis. 1

Fibrosis Assessment with Liver Stiffness Measurement (LSM)

Rule-Out Cutoffs (High Sensitivity)

LSM <8.0 kPa effectively excludes advanced fibrosis (F3-F4) with >90% sensitivity and negative predictive values >80% across all clinical populations. 1 This cutoff is recommended by EASL 2021 guidelines as a first-line test to rule out advanced fibrosis in NAFLD patients. 1

• Patients with LSM <8.0 kPa are considered low risk and should undergo repeat surveillance testing in 2-3 years. 1
• Among 1,073 NAFLD patients from 10 European centers, the 8.0 kPa cutoff demonstrated 93% sensitivity for excluding advanced fibrosis. 1

Rule-In Cutoffs (High Specificity)

LSM ≥12.0 kPa indicates clinically significant fibrosis is likely, with positive predictive values of 76-88% in diabetes and hepatology populations. 1

• Patients with LSM ≥12.0 kPa should be referred to hepatology for consideration of liver biopsy or magnetic resonance elastography (MRE). 1
• The combination of FIB-4 >2.67 and LSM ≥12.0 kPa is highly suggestive of advanced liver fibrosis. 1

Detailed Fibrosis Stage Cutoffs

The 2025 AASLD systematic review provides specific cutoffs for each fibrosis stage in NAFLD: 1

• Significant fibrosis (F≥2): 7.0 kPa (sensitivity 76%, specificity 73%)
• Advanced fibrosis (F≥3): 10.0 kPa (sensitivity 82%, specificity 79%)
• Cirrhosis (F4): 13.0 kPa (sensitivity 90%, specificity 89%)

A 2024 meta-analysis suggests 7.1-7.9 kPa as the optimal benchmark to rule out advanced fibrosis, with the highest diagnostic performance in this range. 1

Important Caveats for LSM Interpretation

Obesity significantly affects LSM values. Non-obese NAFLD patients (BMI <25 kg/m²) have LSM values approximately 3.5 kPa lower than obese patients at the same fibrosis stage. 2 Consider using lower cutoffs in non-obese patients:

• Non-obese: 5.8 kPa (≥F1), 7.6 kPa (≥F2), 9.1 kPa (≥F3), 12.5 kPa (F4)
• Obese: 7.5 kPa (≥F1), 8.5 kPa (≥F2), 11.2 kPa (≥F3), 14.3 kPa (F4) 2

Quality criteria are essential: Ensure at least 10 validated measurements with interquartile range <30% of median value and success rate >60%. 1

Steatosis Assessment with Controlled Attenuation Parameter (CAP)

CAP values ≥275 dB/m have >90% sensitivity and positive predictive value for detecting hepatic steatosis in NAFLD. 1 However, there are no universally consensual cutoffs, and CAP performance varies by steatosis grade.

Steatosis Grade Cutoffs

Based on EASL 2021 guidelines and supporting studies: 1

• Any steatosis (S≥1): 263-274 dB/m (high sensitivity >90%)
• Moderate steatosis (S≥2): >250-268 dB/m
• Severe steatosis (S3): 280-294 dB/m

The optimal cutoff for detecting any steatosis using the XL probe is 294 dB/m (sensitivity 79%, specificity 74%), but if >90% sensitivity is required, use 263 dB/m. 1

CAP Performance Limitations

CAP has suboptimal performance for quantifying steatosis grades, with AUROCs of 0.70-0.77 for S≥2 and 0.58-0.70 for S3. 1 It is outperformed by MRI-PDFF for steatosis quantification. 1

• Use XL probe when available to reduce failure rates (3-4% vs 21% with M probe). 1
• Quality criteria include CAP IQR <30-40 dB/m, though not externally validated. 1
• CAP values are influenced by NAFLD, diabetes, and BMI. 1

Sequential Testing Strategy

A two-tier approach using FIB-4 followed by LSM for indeterminate scores is more accurate than using tests individually. 1

Recommended Algorithm:

1. First tier: Calculate FIB-4 score

   • FIB-4 <1.3: Low risk, repeat testing in 2-3 years 1
   • FIB-4 1.3-2.67: Indeterminate, proceed to LSM 1
   • FIB-4 >2.67: High risk, refer to hepatology 1

2. Second tier (for FIB-4 1.3-2.67): Perform LSM

   • LSM <8.0 kPa: Low risk, surveillance in 2-3 years 1
   • LSM 8.0-12.0 kPa: Intermediate risk, closer monitoring
   • LSM ≥12.0 kPa: High risk, refer to hepatology 1

This sequential approach reduces the need for liver biopsies from 33% to 19% while maintaining diagnostic accuracy. 1

Alternative Imaging Modalities

Magnetic resonance elastography (MRE) is the most accurate non-invasive method for staging fibrosis but is not recommended as first-line due to cost and limited availability. 1

MRE cutoffs for NAFLD: 1

• Significant fibrosis (F≥2): 3.4 kPa (sensitivity 78%, specificity 90%)
• Advanced fibrosis (F≥3): 3.7 kPa (sensitivity 82-93%, specificity 90-95%)
• Cirrhosis (F4): 6.7 kPa (sensitivity 91%, specificity 95%)

A 2024 meta-analysis suggests 3.62-3.8 kPa as the optimal cutoff for advanced fibrosis with MRE. 1