Ultrasound of the Liver in Pediatric Steatosis: MASLD Instead of NAFLD, ESPGHAN 2024
What the ESPGHAN 2024 Statement Changed
The multidisciplinary ESPGHAN statement on pediatric steatotic liver disease supported the transition from the term NAFLD to the new nomenclature SLD/MASLD. The document emphasizes that pediatric steatotic liver disease has unique characteristics and should not automatically replicate the adult model. Reference to the primary source: ESPGHAN multisociety statement, 2024.
The key practical change: NAFLD was a diagnosis of exclusion, tied to the absence of significant alcohol and other causes. MASLD is a positive diagnosis: there is liver steatosis and metabolic dysfunction. For the ultrasound diagnostician, this means that the conclusion should not replace the clinical classification.
New Terminology: How to Write and Understand
| Term | Meaning in the New Nomenclature | What is Important for Ultrasound |
|---|---|---|
| SLD | Steatotic liver disease, a general umbrella term for steatotic liver diseases | Ultrasound can detect steatosis but does not determine the etiological category |
| MASLD | Metabolic dysfunction-associated steatotic liver disease: steatosis plus at least one cardiometabolic factor | In the protocol, it is correct to write "echographic signs of steatosis," and MASLD should be indicated only if clinical data are available |
| MASH | Metabolic dysfunction-associated steatohepatitis | Not an ultrasound diagnosis; requires clinical-laboratory and, if indicated, morphological verification |
| Specific aetiology SLD | Steatosis with an established other cause | Ultrasound does not exclude drug, genetic, endocrine, and other causes |
| Cryptogenic SLD | Steatosis without an established cause after evaluation | Not every steatosis without obesity should be turned into MASLD |
The Role of Ultrasound in a Child with Steatosis
Ultrasound is the practical first imaging method when suspecting fatty infiltration of the liver in a child: it is accessible, safe, does not require radiation exposure, and allows simultaneous assessment of liver size, parenchymal structure, bile ducts, spleen, and signs of portal hypertension.
However, standard grayscale ultrasound is qualitative and semi-quantitative. It better recognizes pronounced steatosis than minimal changes, depends on the equipment, probe, child's body habitus, and operator's experience. Therefore, normal liver echogenicity does not exclude early or mild steatosis, and pronounced hyperechogenicity does not equate to a diagnosis of MASH or fibrosis.
Echographic Signs Worth Describing
In the protocol, it is useful to record specific signs rather than limit to the phrase "fatty liver." Typical for steatosis are diffuse increased echogenicity of the parenchyma, enhanced contrast between the liver and the renal cortex of the right kidney, dorsal attenuation of ultrasound, and impaired visualization of intrahepatic vessels and diaphragm.
The severity is better formulated as "mild," "moderate," or "severe" echographic signs of steatosis if such gradation is accepted in the department. It is important not to present this gradation as an exact measurement of fat fraction. If elastography or a quantitative attenuation assessment method is available, their results should be separated from the description of the grayscale image and interpreted according to validated local protocols.
How Not to Confuse Steatosis and MASLD
Echographic steatosis is a visualization phenomenon. MASLD is a clinico-metabolic category. According to the ESPGHAN 2024 statement, transitioning to MASLD means that steatosis alone is insufficient: a connection with metabolic dysfunction is needed. Therefore, an ultrasound physician can suggest MASLD correspondence only if there is data on cardiometabolic factors in the referral or medical record.
Optimal wording: "Echographic signs of diffuse liver steatosis. If cardiometabolic factors are present, changes may correspond to MASLD; clinical-laboratory correlation is required." This phrase maintains diagnostic accuracy and helps the clinician apply the new nomenclature.
Why the Term NAFLD is Leaving Pediatric Practice
The term NAFLD was built around negation: "non-alcoholic" liver disease. For children, this logic is particularly inconvenient because alcohol is usually not the main differential criterion, and the causes of steatosis are broader: obesity and insulin resistance, hereditary and metabolic diseases, endocrine conditions, drug influences, dietary features, and systemic diseases.
The new SLD nomenclature first acknowledges the fact of steatosis, then relates it to metabolic, alcohol-associated, specific, or cryptogenic variants. For pediatrics, this is fundamental: a child with steatosis without obvious obesity should not automatically receive the MASLD label without searching for other causes.
What Should Alert in the Ultrasound Protocol
In pediatric steatosis, ultrasound should not only confirm liver hyperechogenicity but also look for signs that change the patient's route. These include hepatomegaly, splenomegaly, ascites, dilation of the portal or splenic vein, collaterals, irregular liver contour, focal formations, signs of cholestasis, or biliary obstruction.
The presence of such findings does not prove MASH but increases the likelihood of advanced liver disease or alternative pathology. In these cases, it is appropriate to explicitly recommend correlation with liver biochemical tests, platelets, metabolic profile, and consultation with a relevant specialist in the conclusion.
Practical Conclusion Template
Description: the liver is normally positioned, sizes are increased or not increased; contours are smooth; parenchyma is diffusely increased in echogenicity; sound transmission is reduced or preserved; intrahepatic vessels are visualized satisfactorily or worse than usual; no focal changes detected; bile ducts are not dilated; spleen is unremarkable or enlarged.
Conclusion: "Echographic signs of diffuse liver steatosis." Addition if data is available: "In the context of obesity, insulin resistance, or other cardiometabolic factors, changes may correspond to MASLD according to the new SLD nomenclature supported by ESPGHAN in 2024." If such data is not available: "The etiology of steatosis is not determined by ultrasound data."
What to Inform the Clinician
For the correct transition from NAFLD to MASLD, the clinician needs not only ultrasound signs of steatosis. Anthropometry, signs of metabolic dysfunction, medication and dietary history, family history, laboratory indicators, and exclusion of other causes of steatosis are needed. Ultrasound should be part of the route, not the final diagnostic label.
The main position of ESPGHAN: use the new nomenclature but consider the uniqueness of the pediatric population. The ultrasound physician aids this task by clearly separating observed steatosis from the clinical diagnosis of MASLD and avoiding the outdated automatic conclusion "NAFLD."
Frequently asked questions
Can MASLD be diagnosed in a child via ultrasound?
No. Ultrasound detects or suggests liver steatosis. MASLD requires steatosis and at least one cardiometabolic factor, so the diagnosis is made clinically, considering laboratory and anamnesis data.
Should the term NAFLD be completely abandoned in the conclusion?
In new protocols, it is better to use SLD/MASLD terminology. For ultrasound, the basic formulation is "echographic signs of liver steatosis"; MASLD is indicated only in the presence of clinical context.
Does pronounced steatosis on ultrasound indicate the presence of MASH?
No. MASH is steatohepatitis, not an ultrasound category. Grayscale ultrasound does not prove inflammation and does not stage the disease; clinical-laboratory assessment is required, and in some cases, morphological verification.