Hepatic panel
FIB-4 index
Non-invasive fibrosis estimate from age, AST, ALT, and platelets.
Sample
Calculated
Biology
What it measures
FIB-4 = (age × AST) / (platelets × √ALT). Reflects loss of platelets and rising AST/ALT ratio in advanced fibrosis.
Clinical use
Why we order it
Triage NAFLD/MASLD: <1.3 (excludes advanced fibrosis), 1.3–2.67 (indeterminate, refer for elastography), >2.67 (likely advanced fibrosis).
Lens · Clinical
Interpretation by lens
Clinical interpretation
AASLD 2023 algorithm: FIB-4 first, then VCTE if indeterminate or high; biopsy reserved.
Pitfalls
Pre-analytic & interpretation traps
- !Less reliable in patients <35 or >65; confirm with VCTE/MR elastography.
Related