What does an S3 result on a FibroScan (Fibrosis Scan) indicate?

Understanding S3 Result on FibroScan

An S3 result on a FibroScan indicates severe hepatic steatosis, meaning that more than 30% of liver cells (hepatocytes) contain fat deposits. 1

What FibroScan Measures

FibroScan (transient elastography) is a non-invasive diagnostic tool that measures two key parameters:

1. Liver Stiffness Measurement (LSM) - measured in kilopascals (kPa), which assesses liver fibrosis
2. Controlled Attenuation Parameter (CAP) - measured in dB/m, which quantifies hepatic steatosis (fat content)

Understanding Steatosis Grading (S0-S3)

The S3 result specifically refers to the steatosis grading, which is categorized as follows:

• S0: Minimal or no steatosis (<5% of hepatocytes)
• S1: Mild steatosis (5-10% of hepatocytes) - CAP value approximately 248 dB/m
• S2: Moderate steatosis (10-30% of hepatocytes) - CAP value approximately 268 dB/m
• S3: Severe steatosis (>30% of hepatocytes) - CAP value ≥280 dB/m 1

Clinical Implications of S3 Result

An S3 result has several important clinical implications:

• Indicates Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) - Previously known as non-alcoholic fatty liver disease (NAFLD)
• Risk for Disease Progression - Severe steatosis can progress to steatohepatitis and fibrosis
• Associated Comorbidities - Strong association with metabolic syndrome, type 2 diabetes, obesity, and cardiovascular disease 1

Recommended Follow-Up Actions

If you have an S3 result on FibroScan:

1. Assess for fibrosis - Check if the liver stiffness measurement (LSM) was also elevated, as this would indicate concurrent fibrosis

   • LSM <8 kPa: Low risk for significant fibrosis 1
   • LSM 8-12 kPa: Indeterminate risk
   • LSM >12 kPa: High risk for advanced fibrosis/cirrhosis 1

2. Evaluate for metabolic risk factors - Screen for:

   • Type 2 diabetes
   • Dyslipidemia
   • Hypertension
   • Obesity 1

3. Consider additional testing:

   • Fibrosis blood tests (FIB-4, APRI)
   • Liver function tests
   • Fasting glucose and lipid profile 1

Management Considerations

For patients with S3 steatosis:

• Lifestyle modifications - Weight loss of 5-10%, Mediterranean diet, regular exercise
• Management of metabolic comorbidities - Optimize control of diabetes, hypertension, and dyslipidemia
• Regular monitoring - Repeat FibroScan in 1-2 years to assess for progression
• Hepatology referral - Consider if there are signs of advanced fibrosis (LSM >12 kPa) 1

Common Pitfalls in Interpreting FibroScan Results

1. Confusing steatosis (S0-S3) with fibrosis (F0-F4) - These are separate measurements
2. Failure to obtain reliable measurements - Occurs in approximately 4.5% of cases, particularly in patients with BMI >28 2
3. Overreliance on a single test - FibroScan should be interpreted in the context of other clinical and laboratory findings
4. Not accounting for acute inflammation - Acute hepatitis can falsely elevate liver stiffness measurements

Remember that while FibroScan is an excellent non-invasive tool, its results should be interpreted in the context of the patient's overall clinical picture and may need to be confirmed with other diagnostic methods in certain cases.