Non-invasive imaging biomarkers for liver steatosis in non-alcoholic fatty liver disease: present and future

Non-alcoholic fatty liver disease is currently the most common chronic liver disease, affecting up to 25% of the global population. Simple fatty liver, in which fat is deposited in the liver without fibrosis, has been regarded as a benign disease in the past, but it is now known to be prognostic. In the future, more emphasis should be placed on the quantification of liver fat. Traditionally, fatty liver has been assessed by histological evaluation, which requires an invasive examination; however, technological innovations have made it possible to evaluate fatty liver by non-invasive imaging methods, such as ultrasonography, computed tomography, and magnetic resonance imaging. In addition, quantitative as well as qualitative measurements for the detection of fatty liver have become available. In this review, we summarize the currently used qualitative evaluations of fatty liver and discuss quantitative evaluations that are expected to further develop in the future.

Automated summary

Non-alcoholic fatty liver disease is the most common chronic liver disease, with a global prevalence of up to 25%. Simple fatty liver, previously considered benign, is now known to have prognostic significance. Future focus should be on quantifying liver fat. Traditional histological evaluation for fatty liver is invasive, but advancements in technology have made non-invasive imaging methods such as ultrasound, CT, and MRI possible. Quantitative and qualitative measurements for detecting fatty liver are available, and this review summarizes current qualitative evaluations and discusses the future development of quantitative evaluations.