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.