Accessible, early assessment for patients at risk of metabolic liver disease

Early assessment of fatty liver is key to potentially reversing disease progression. [2] Recent multidisciplinary clinical care pathways recommend screening at-risk populations and using noninvasive tools to detect steatosis, stratify fibrosis risk and monitor treatment response over time. 

Liver biopsies have been the traditional method for diagnosis but present the risk of complications and sampling variability. [3] MRI-derived proton density fat fraction (MRI-PDFF) is an accurate, reproducible noninvasive biomarker for quantifying liver fat, [4] but cost and limited access remain barriers for widespread use. Ultrasound-based liver fat quantification addresses the need for an accessible, noninvasive tool that can be integrated into existing clinical workflows for the large population of patients at risk for MASLD. [1] 

The Philips Liver Fat Quantification (LFQ) solution allows the user to measure liver attenuation using the attenuation quantification tool and characterize the relative echogenicity of the liver using the hepatorenal index (HRI) tool.  

The presence of fat in the liver increases the attenuation of the ultrasound beam as it travels through tissue. By measuring how much signal intensity is lost per unit of depth, the attenuation coefficient provides a quantitative indicator of liver fat content where higher attenuation values correspond to greater fat accumulation. 

The LFQ attenuation coefficient has been validated in clinical studies using MRI proton-density fat fraction (MRI-PDFF) as the reference standard. 

 Attenuation confidence map 

The confidence map is a built-in quality indicator that helps guide ROI placement for reliable attenuation measurements. It evaluates the quality of the attenuation estimate at every pixel within the imaging region. The confidence score ranges from 0% (very poor) to 100% (excellent).  

A user-controlled confidence threshold (CT) masks pixels below the selected threshold within the attenuation image. Pixels that fall below the CT are excluded from the measurement when an ROI is placed, ensuring that only reliable data contributes to the reported attenuation value.  

The hepatorenal index tool calculates the ultrasound echo amplitude by selecting regions of interest (ROIs) within the liver parenchyma and the kidney cortex at the same depth, and by evaluating the ratio between the average echo amplitude in the liver ROI over that of the kidney ROI. Excessive fat infiltration in the liver increases acoustic backscattering, thereby leading to higher echo amplitude values from the liver in the ultrasound 2D image. At a normal state, liver parenchyma and renal cortex have similar echogenicity. With more fat deposits, the liver appears more hyperechoic (i.e., brighter) than the kidney cortex. 

Philips HRI quantification tool works on-cart and within the signal processing chain of the ultrasound system. Operator-dependent system settings such as compression, gain and gray maps are known and can be compensated for prior to calculating the HRI value. The net result is an HRI measurement that is consistent despite different user imaging preferences.  

The Philips Liver Fat Quantification package provides clinicians with a practical, accessible tool for assessing hepatic steatosis during routine ultrasound examinations – without the cost, scheduling delays or limited availability associated with MRI. The combination of attenuation quantification, HRI and the confidence map gives users a complete workflow: acquire, assess quality, measure and interpret – all within a single exam session. For patients who also require liver stiffness assessment, LFQ integrates seamlessly with ElastQ to support comprehensive evaluation of both fat and fibrosis in a single exam session. Together, these capabilities help clinicians integrate ultrasound across the patient journey, from early detection through longitudinal monitoring and treatment response assessment in patients with metabolic liver disease.