Noninvasive liver fibrosis assessment in metabolic dysfunction-associated steatotic liver disease

Table 1 Steatotic liver disease nomenclature

Nomenclature	Definition
NAFLD	Nonalcoholic fatty liver disease is defined by the presence of ≥ 5% of macrovesicular steatosis and the absence of an identified alternative diagnosis, as well as a significant ongoing or recent alcohol consumption (defined as < 30 g/day for men and < 20 g/day for women)
NASH	Presence of inflammation and cellular injury expressed by ballooning
MAFLD	Presence of steatosis evidenced by histology, imaging, or blood biomarker in addition to one of the following criteria: Overweight/obesity, type 2 diabetes mellitus, or evidence of metabolic syndrome
SLD	Presence of steatosis diagnosed histologically or by imaging techniques
MASLD	Presence of SLD associated with at least one cardiometabolic risk factor and no other identified cause, alcohol consumption should be less than 20 g/day for women and 30 g/day for men, previously called NAFLD
MASH	Presence of MASLD and cellular inflammation and/or injury, previously mentioned as NASH
Met-ALD	Met-ALD was recently proposed, defined as the presence of SLD and alcohol consumption between 20-50 g/day in women and 30-60 g/day in men

MAFLD: Metabolic dysfunction-associated fatty liver disease; MASH: Metabolic steatohepatitis; MASLD: Metabolic steatotic liver disease; Met-ALD: Metabolic steatotic liver disease with moderate alcohol consumption; NAFLD: Nonalcoholic liver disease; NASH: Nonalcoholic steatohepatitis; SLD: Steatotic liver disease.

Table 2 Parameters for noninvasive assessment of advanced fibrosis in metabolic dysfunction-associated steatotic liver disease

NIM	Rule-in cutoff	Rule-out cutoff	AUROC1	Strengths and limitations
Biomarkers
APRI	< 0.5	> 1.5	0.74	False positive in patients with alternative causes of thrombocytopenia
FIB-4	< 1.32; < 1.67	≥ 2.67; ≥ 3.483	0.84	No added cost; low accuracy in patients younger than 35 years; low specificity in those older than 65 years
NFS	< -1.44	≥ 0.672	0.82	No added cost; not accurate in age < 35 years, people with obesity and type 2 diabetes Restricted use to MASLD
ELF	< 7.7; < 7.73	≥ 9.8; ≥ 11.33	0.83	Cost and not widely available; less useful for early fibrosis
Imaging techniques
VCTE	< 8 kPa; < 8 kPa3	≥ 12 kPa; ≥ 20 kPa3	0.9	Point of care, possibility of steatosis degree evaluation; necessity of specific device; confounded by active hepatitis, food intake, congestive heart failure, biliary obstruction, amyloidosis, ascites; less applicable and reliable in severe obesity (especially with M probe)
pSWE (ARFI)	< 1.3 m/second	> 2.1 m/second	0.8-0.9	Integration into conventional ultrasound systems, which enables a comprehensive evaluation of the liver at the same time; cut points not well validated; Probably affected by the same confounders as VCTE, though the success rate is higher than VCTE in obese patients
2D-SWE	< 8 kPa	> 12 kPa	0.80-0.98	Integration into conventional ultrasound systems, which enables a comprehensive evaluation of the liver at the same time; cut points not well validated; probably affected by the same confounders as VCTE
MRE	< 2.55 kPa; < 3 kPa3	≥ 3.63kPa; ≥ 5 kPa3	0.89-0.96	Superior performance in detecting early-stage fibrosis; integration into routine liver MRI allows both fibrosis staging and surveillance of other liver pathologies, such as HCC; cost, not widely available; probably affected by the same confounders as VCTE and iron content; some patients may have contraindications to magnetic resonance imaging or have claustrophobia

¹For F3-F4.

²A lower cutoff of 2 can be used for patients older than 65 years.

³To rule in or rule out cirrhosis.

2D-SWE: Two-dimensional shear wave elastography; APRI: Aspartate aminotransferase to platelet ratio index; ARFI: Acoustic radiation force impulse; AUROC: Area under the curve; ELF: Enhanced liver fibrosis; FIB-4: Fibrosis-4 index; MRE: Magnetic resonance elastography; NFS: Nonalcoholic fatty liver disease fibrosis score; NIM: Noninvasive method; pSWE: Point shear-wave; VCTE: Vibration-controlled transient elastography; HCC: Hepatocellular carcinoma.