Ultrasound Fatty Liver Indicator: A Simple Tool for Differentiating Steatosis From Nonalcoholic Steatohepatitis: Validity in the Average Obese Population

Abstract

Objectives Steatosis, nonalcoholic steatohepatitis (NASH), and fibrosis/cirrhosis represent a spectrum of fatty liver disease. The ultrasound fatty liver indicator (US‐FLI) evaluates ultrasound (US) features to identify stages of fatty liver disease. We hypothesized that US features could be independent predictors of NASH and that the US‐FLI differentiates steatosis from NASH in the average obese population. Methods A retrospective analysis of 208 patients with normal (n = 14), steatotic (n = 89), and NASH (n = 105) livers was performed. Liver/biliary disease and a history of alcohol intake were excluded. Ultrasound metrics included liver‐kidney contrast, posterior attenuation, vessel blurring, difficulty visualizing the gallbladder wall, difficulty visualizing the diaphragm, and areas of focal fatty sparing. A statistical comparison of the 3 groups as well as fibrosis stage I and II/III NASH groups was performed. Logistic regression identified independent predictors of NASH. Results Gallbladder wall visualization and vessel blurring were different between the steatosis and NASH groups (P ≤ .01). Gallbladder wall visualization was specific for NASH (89%), and vessel blurring was sensitive for NASH (93%). A US‐FLI score of 4 or lower suggested the absence of NASH (negative predictive value, 88%; sensitivity, 91%). Logistic regression revealed vessel blurring as the only US predictor of NASH (P ≤ .01). However, the area under the curve (0.649) showed poor performance in differentiating steatosis from NASH when the US‐FLI score was 5 or higher. Conclusions Our data suggest that the US‐FLI may differentiate steatosis from NASH in the average obese population. Vessel blurring and poor gallbladder wall visualization were the most important metrics. Identification of NASH was enhanced by including the US‐FLI score with vessel blurring.

Gender Differences in the Relationships among Metabolic Syndrome and Various Obesity-Related Indices with Nonalcoholic Fatty Liver Disease in a Taiwanese Population

“…Ballestri S et al showed ultrasonographic fatty liver indicator (US-FLI) can accurately identify the severity of histology and is also correlated with WC, BMI, and IR with various steatogenic liver diseases [34]. In addition, Nelson SM et al demonstrated that US-FLI may differentiate steatosis from NASH in the average obese population [35]. Praveenraj et al reported that BMI, WC and WHR had the best predictive ability for NAFLD in a cohort of morbidly obese women [36].…”

Diagnostic Modalities of Non-Alcoholic Fatty Liver Disease: From Biochemical Biomarkers to Multi-Omics Non-Invasive Approaches

“…Diagnostic accuracy of the ultrasound is also limited in patients with fibrosis, chronic liver dysfunction, high body mass index (BMI > 40 kg/m 2 ) or in the presence of ascites [ 141 , 142 , 143 ]. These limitations can be partially overcome with the use of semi-quantitative measures, such as the ultrasonographic fatty liver indicator (US-FLI score) [ 144 ]. The US-FLI uses sonographic metrics (hepato-renal contrast, posterior attenuation, blurring of portal veins and hepatic veins, limited visualisation of the gallbladder wall, limited visualisation of the diaphragm and areas of focal fatty sparing) to generate a score of mild, moderate and severe steatosis.…”

“…Studies demonstrate excellent inter-observer reproducibility and good differentiation of severity, with high specificity (90%) and sensitivity (90%) even in mild steatosis (>10% fatty infiltration) [ 145 , 146 ]. The US-FLI score has also been found to differentiate steatosis from NASH in the obese population, especially when the score is ≤4 with a negative predictive value of 88% and sensitivity of 91% for absence of NASH [ 144 ].…”

Association between the Severity of Nonalcoholic Fatty Liver Disease and the Risk of Coronary Artery Calcification

“…Our study analyzed the retrospective ultrasonographic records describing by the original criteria which performed by Saverymuttu et al [ 13 ]. The criteria were widely accessed by general physicians, and our ultrasonographic findings were still valuable in differentiating from steatosis to nonalcoholic steatohepatitis (NASH) [ 45 , 46 , 47 ]. Our study design was limited by the initial health care setting to confidently exclude advanced fibrosis, but we still focused on the relationship between ultrasonographic finding and specific coronary calcification.…”