Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is one of the most prevalent chronic liver conditions globally. Its association with metabolic syndrome, including conditions such as obesity, diabetes, and hypertension, makes accurate diagnosis crucial for managing patients at risk of advanced liver disease and related complications. Invasive liver biopsies have long been the gold standard for assessing steatosis and fibrosis. Still, newer non-invasive techniques, such as ultrasound-guided attenuation parameters (UGAP) and two-dimensional shear wave elastography (2D-SWE), are being explored for their effectiveness in clinical settings.
Role of UGAP in Diagnosing Hepatic Steatosis
UGAP is a relatively new ultrasound-based technology designed to quantify liver fat non-invasively. In the study under review, UGAP measurements demonstrated high reliability and accuracy in detecting moderate to severe hepatic steatosis. Median UGAP values were positively correlated with the histopathological grading of steatosis, demonstrating a clear distinction between different grades of liver fat accumulation. This technology has shown promise as a more accessible and user-friendly tool in clinical practice, where liver biopsy is not always feasible due to its invasiveness, risk of complications, and cost.
One of the main benefits of UGAP is its high inter-operator and intra-operator reproducibility, as demonstrated in this study. Even when performed by radiologists with varying experience levels, UGAP maintained excellent reliability, suggesting that it could be widely adopted in diverse healthcare settings. Moreover, UGAP was more accurate than the controlled attenuation parameter (CAP), another non-invasive method, which often showed a higher failure rate in patients with a higher body mass index (BMI).
Evaluating 2D-SWE for Fibrosis Detection
While UGAP focuses on detecting hepatic steatosis, 2D-SWE is primarily used to assess liver stiffness, a key indicator of fibrosis. Fibrosis progression can lead to cirrhosis, liver failure, and hepatocellular carcinoma if not detected and managed early. The study found that 2D-SWE had good diagnostic performance for detecting both significant (F2-F4) and advanced (F3-F4) fibrosis, with an optimal cut-off value of 6.75 kPa for advanced fibrosis. Patients with elevated liver stiffness, as measured by 2D-SWE, showed a moderate correlation with fibrosis staging.
However, the effectiveness of 2D-SWE was slightly limited in individuals with high BMI or a large skin-to-liver capsule distance, which often resulted in invalid measurements. Despite these limitations, 2D-SWE's non-invasive nature, combined with its capability to provide real-time feedback, makes it a valuable tool for liver fibrosis assessment, especially in clinical settings where regular liver monitoring is necessary.
Benefits of Combined Assessment for MASLD
One of the major strengths of using both UGAP and 2D-SWE in combination is the ability to conduct a multi-parametric ultrasound assessment of MASLD patients. In a single non-invasive exam, healthcare providers can evaluate liver steatosis and fibrosis, enabling them to stratify patients according to their risk of disease progression and tailor treatment plans accordingly. The ability to perform both tests during the same ultrasound session makes the process more efficient and cost-effective.
Furthermore, both UGAP and 2D-SWE have the potential to be used for follow-up assessments, which are crucial for monitoring treatment efficacy and disease progression over time. Since MASLD is strongly linked to metabolic dysfunction, patients may require long-term monitoring, and non-invasive tools like UGAP and 2D-SWE offer practical, safe alternatives to liver biopsy and magnetic resonance imaging (MRI), which are more invasive or expensive.
Ultrasound-guided attenuation parameters and two-dimensional shear wave elastography have shown promising results in non-invasive liver assessment for patients with metabolic dysfunction-associated steatotic liver disease. UGAP, in particular, has proven effective for diagnosing moderate to severe hepatic steatosis, with high reliability and reproducibility across different operators. Similarly, 2D-SWE offers valuable insights into liver stiffness and fibrosis, although it faces challenges with patients with high BMI. Together, these tools can enhance the diagnosis and monitoring of MASLD, providing a comprehensive, non-invasive approach to managing this increasingly common liver condition.
Source: European Radiology
Image Credit: iStock
