Non-Invasive Tests in the Management of Metabolic Dysfunction-Associated Steatotic Liver Disease: From Diagnosis to Treatment Monitoring

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects approximately 30% of the global adult population, and accurate identification of patients with clinically significant fibrosis is critical for risk stratification and therapeutic decision-making. Non-invasive tests (NITs)—encompassing serum-based biomarkers, vibration-controlled transient elastography (VCTE), magnetic resonance elastography, and magnetic resonance imaging-derived proton density fat fraction—have emerged as indispensable tools across the MASLD management continuum. The sequential two-step pathway combining FIB-4 with liver stiffness measurement by VCTE has been validated as the standard framework for fibrosis triage, demonstrating a more than 20-fold gradient in 5-year liver-related event rates between low- and high-risk categories. In the clinical trial setting, NITs have progressively evolved from exploratory secondary endpoints to regulatory co-primary endpoints, culminating in the FDA approvals of resmetirom (2024) and semaglutide (2025) for noncirrhotic metabolic dysfunction-associated steatohepatitis with F2–F3 fibrosis. NIT-based algorithms are now formalized for both patient selection and serial treatment response monitoring, effectively operationalizing a biopsy-sparing treat-and-monitor paradigm in routine clinical practice. Achieving full regulatory acceptance of NIT-only trial designs—requiring prospective validation that NIT-defined response categories predict long-term liver-related outcomes—represents the next critical frontier in MASLD management.