Abdominal ultrasound for diagnosis of nonalcoholic fatty liver disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease. The progressive subtype of NAFLD or nonalcoholic steatohepatitits (NASH), may progress to cirrhosis and its complications. Unfortunately, accurate noninvasive modalities for diagnosing NASH and monitoring its progression are unavailable, necessitating a liver biopsy. Abdominal ultrasound (US) is widely used for screening asymptomatic patients with an incidental elevation of liver enzymes. However, US cannot detect small amounts of hepatic steatosis and cannot establish the diagnosis of NASH or stage of hepatic fibrosis. In this issue of AJG, a new radiologic scoring system has been reported to have excellent performance in diagnosing NAFLD and visceral obesity. However, the utility of this scoring system in establishing the diagnosis of NASH and hepatic fibrosis, has not been shown. Additionally, validity of this scoring system to other populations (i.e. obese) and in the setting of private practice must be proven. In summary, this study provides some valuable data regarding the utility of radiologic modalities in detecting hepatic steatosis and abdominal fat but still falls short in answering some important diagnostic and prognostic questions in NAFLD. The evolving field of diagnostic imaging for NAFLD holds promise. A combination of serum biomarkers and radiologic modalities may one day provide the best diagnostic approach for patients with NAFLD, and potentially replace the necessity for liver biopsy in most patients.