When should a FibroScan (Fibrosis Scan) be ordered for a patient with ultrasound findings suggestive of fatty liver disease?

When to Order FibroScan for Patients with Fatty Liver on Ultrasound

FibroScan should be ordered after initial risk stratification with FIB-4 score for patients with ultrasound-detected fatty liver who have intermediate or high risk for advanced fibrosis, particularly those with metabolic risk factors such as diabetes, obesity, or metabolic syndrome. 1

Risk Stratification Algorithm

Step 1: Identify High-Risk Patients

• Patients with ultrasound findings of fatty liver should be assessed for risk factors 1:
  • Type 2 diabetes (especially >10 years duration or age >50) 1
  • Obesity (BMI >35 kg/m²) 1
  • Metabolic syndrome 1
  • Elevated liver enzymes 1

Step 2: Initial Non-Invasive Testing with FIB-4

• Calculate FIB-4 score: (age × AST)/(platelets × √ALT) 1
• Interpret FIB-4 results 1:
  • Low risk: FIB-4 <1.3 (<2.0 for patients >65 years)
  • Indeterminate risk: FIB-4 1.3-2.67
  • High risk: FIB-4 >2.67

Step 3: FibroScan Indications

• Order FibroScan for patients with 1, 2:
  • Indeterminate FIB-4 (1.3-2.67)
  • High FIB-4 (>2.67)
  • Persistent elevated liver enzymes despite low FIB-4 3
  • Multiple risk factors for fibrosis progression 3

Interpretation of FibroScan Results

• Liver stiffness measurement (LSM) thresholds 1, 2, 3:
  • <8 kPa: Low risk of significant fibrosis
  • 8-12 kPa: Indeterminate risk, possible advanced fibrosis

  • 12 kPa: High risk, likely advanced fibrosis/cirrhosis

Management Based on Results

• Low risk (FIB-4 <1.3 or LSM <8 kPa) 1:

  • Manage in primary care
  • Focus on lifestyle modifications
  • Repeat risk assessment in 2-3 years

• Indeterminate risk (LSM 8-12 kPa) 1, 2:

  • Consider hepatology referral
  • More intensive monitoring
  • Repeat assessment in 1-2 years

• High risk (LSM >12 kPa) 1:

  • Refer to hepatologist
  • Consider liver biopsy or additional testing
  • Evaluate for complications of advanced liver disease

Special Considerations

• FibroScan has limitations in certain populations 2, 3:

  • Severe obesity may require XL probe 4
  • Ascites makes results unreliable 3
  • Acute hepatitis can falsely elevate readings 3

• Diabetes significantly reduces the accuracy of FIB-4 (c-statistic 0.68 vs 0.85 in non-diabetics), making FibroScan particularly important in these patients 5

• Sequential testing using FIB-4 followed by FibroScan is more accurate than either test alone 1, 2

• For reliable FibroScan results, ensure 2, 3:

  • ≥10 successful measurements
  • Success rate of at least 60%
  • Interquartile range less than 30% of median value

This approach allows for appropriate risk stratification and targeted use of FibroScan, focusing resources on patients most likely to benefit from advanced fibrosis assessment while avoiding unnecessary testing in low-risk individuals.