Accuracy of ultrasonographic fatty liver index using point-of-care ultrasound in stratifying non-alcoholic fatty liver disease patients

Abstract

Background: The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing in the USA. Some of these patients develop non-alcoholic steatohepatitis (NASH), which can progress to cirrhosis. Ultrasound imaging is one of the most used modalities for diagnosing hepatic steatosis. Primary care providers are increasingly using point-of-care ultrasound (POCUS), which could increase the number of subjects diagnosed with NAFLD. This study evaluates the accuracy of POCUS in identifying patients with NASH.

Methods: Patients with hepatic steatosis without excess alcohol intake or other liver diseases undergoing liver biopsy were included in this study. These patients underwent POCUS and vibration-controlled transient elastography (VCTE) evaluations within 3 months of a liver biopsy. A comparison of POCUS data with liver histology and VCTE were made to assess the validity of POCUS evaluation in diagnosing NAFLD and NASH.

Results: The steatosis score from the liver histology had a low correlation with the controlled attenuation parameter score from VCTE ( r = 0.27) and a moderate correlation with the grade of steatosis detected by the POCUS exam ( r = 0.57). The NAFLD activity score on histology was found to correlate with the ultrasonographic fatty liver index (USFLI) from the POCUS exam ( r = 0.59). A USFLI ≥ 6 diagnosed NASH with a sensitivity of 81%, and a value of ≤3 ruled out the diagnosis of NASH with a sensitivity of 100%.

Conclusion: The provider can use the POCUS exam in clinical practice to diagnose NAFLD and reliably stratify patients who have NASH.