Table 1.
Assessment of NAFLD diagnostic modalities
| Diagnostic test | Pros | Cons |
|---|---|---|
| NAFLD fibrosis score (NFS) | • Non-invasive • Easy to obtain parameters and calculate • Useful at extremes to rule-out or rule-in advanced fibrosis • May allow primary care providers to triage need for hepatology consultation |
• Less reliable with ages < 35 or > 65 • Large range of indeterminate values necessitating further evaluation |
| FIB-4 score | • Non-invasive • Easy to obtain parameters and calculate • Useful at extremes to rule-out or rule-in advanced fibrosis • May allow primary care providers to triage need for hepatology consultation |
• Less reliable with ages < 35 or > 65 • Large range of indeterminate values necessitating further evaluation |
| Ultrasound | ||
| Conventional | • Non-invasive • Widely available, inexpensive • Evaluates liver morphology, splanchnic vessel patency, spleen size |
• Operator dependent • Estimation of steatosis is subjective • Adequacy limited by habitus |
| Quantitative | • Quantifies degree of steatosis • Controlled attenuation parameter (CAP) reported along with liver stiffness measurement (LSM) on VCTE* |
• Less widely available • Does not quantify fibrosis |
| Elastography | ||
| VCTE* | • Non-invasive • Inexpensive • Useful at extremes to rule-out or rule-in advanced fibrosis • Quantify steatosis (CAP) |
• Requires specialized training to perform and interpret • Examination adequacy limited by habitus • Biopsy may still be required if discordant results with clinical picture or to confirm advanced fibrosis |
| pSWE/2D-SWE | • Similar accuracy to VCTE | • Obesity may increase likelihood of unreliable examination • High interobserver variability |
| MRE | • Whole liver estimation (minimal sampling error) • Sensitive for stage 2–4 fibrosis • Improved accuracy in obese individuals as compared to other modalities |
• Expensive • Requires special expertise to interpret • Massive ascites limits accuracy |
| Biopsy | • Widely available • Gold standard for histologic assessment and necessary to diagnose NASH (vs. NAFLD) |
• Invasive, risk of complications • Sampling error • Requires pathology expertise |
*
Most prominent device on market = Fibroscan® (Echosens, Paris, France). VCTE: Vibration controlled transient elastography; pSWE: proton shear wave elastography; 2D-SWE: 2-dimensional shear wave elastography; MRE: magnetic resonance elastography; FIB-4: fibrosis-4; NAFLD: nonalcoholic fatty liver disease.