Ultrasonographic fatty liver indicator, a novel score which rules out NASH and is correlated with metabolic parameters in NAFLD

Background: Differentiating steatosis from NASH is key in deciding treatment and follow-up schedules. We hypothesized that sonographic grading of steatosis will correlate with metabolic and pathologic changes of NASH. Methods: Fifty-three non-consecutive patients had a semi-quantitative evaluation of hepatic steatosis through ultrasonographic Fatty Liver Indicator (US-FLI) just prior to liver biopsy. All biopsies demonstrated NAFLD. US-FLI is a new scoring system ranging 2-8 based on the intensity of liver/kidney contrast, posterior attenuation of ultrasound beam, vessel blurring, difficult visualization of gallbladder wall, difficult visualization of the diaphragm and areas of focal sparing. NAFLD is diagnosed by the minimum score >= 2. Ultrasonographic findings were correlated with metabolic and histological data. Inter-observer US-FLI score agreement, evaluated by three different operators in 31 consecutive patients with steatosis, showed "almost perfect/substantial" agreement (P < 0.001). Results: US-FLI showed a positive correlation with HOMA, insulin, uric acid, ferritin, ALT and bilirubin and was associated with steatosis extent assessed histologically and histological features of NASH, except for fibrosis. US-FLI was an independent predictor of NASH (OR 2.236; P = 0.007) and a US-FLI < 4 had a high negative predictive value (94%) in ruling out the diagnosis of severe NASH according to Kleiner's criteria. Conclusion: Data confirm the hypothesis that US-FLI significantly correlates with metabolic derangements and individual pathologic criteria for NASH and may better select patients for liver biopsy.