Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Mar 21, 2019; 25(11): 1307-1326
Published online Mar 21, 2019. doi: 10.3748/wjg.v25.i11.1307
Noninvasive evaluation of nonalcoholic fatty liver disease: Current evidence and practice
Jiang-Hua Zhou, Jing-Jing Cai, Zhi-Gang She, Hong-Liang Li
Jiang-Hua Zhou, Zhi-Gang She, Hong-Liang Li, Department of Cardiology, Renmin Hospital of Wuhan University, Institute of Model Animal of Wuhan University, Wuhan 430071, Hubei Province, China
Jing-Jing Cai, Department of Cardiology, The 3rd Xiangya Hospital of Central South University, Changsha 410013, Hunan Province, China
Author contributions: Zhou JH and Cai J performed the literature search and wrote the paper; Li H and She ZG supervised and approved the final version of the review.
Supported by the Key Project of the National Natural Science Foundation (No. 81630011, to H.L.); the National Science Fund for Distinguished Young Scholars (No. 81425005, to H.L.); the Major Research Plan of the National Natural Science Foundation of China (No. 91639304 and No. 91729303, to H.L.); the Creative Group Project of Hubei Province (No. 2016CFA010, to H.L.); the Hubei Science and Technology Support Project (No. 2018BEC473, to H.L.).
Conflict-of-interest statement: No potential conflicts of interest exist.
Open-Access: This is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Hong-Liang Li, MD, PhD, Professor, Department of Cardiology, Renmin Hospital of Wuhan University, Institute of Model Animal of Wuhan University, No. 115, Donghu Road, Wuchang District, Wuhan 430071, Hubei Province, China.
Telephone: +86-27-68759302 Fax: +86-27-68759302
Received: January 14, 2019
Peer-review started: January 18, 2019
First decision: January 30, 2019
Revised: February 20, 2019
Accepted: February 22, 2019
Article in press: February 22, 2019
Published online: March 21, 2019

With the increasing number of individuals with diabetes and obesity, nonalcoholic fatty liver disease (NAFLD) is becoming increasingly prevalent, affecting one-quarter of adults worldwide. The spectrum of NAFLD ranges from simple steatosis or nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH). NAFLD, especially NASH, may progress to fibrosis, leading to cirrhosis and hepatocellular carcinoma. NAFLD can impose a severe economic burden, and patients with NAFLD-related terminal or deteriorative liver diseases have become one of the main groups receiving liver transplantation. The increasing prevalence of NAFLD and the severe outcomes of NASH make it necessary to use effective methods to identify NAFLD. Although recognized as the gold standard, biopsy is limited by its sampling bias, poor acceptability, and severe complications, such as mortality, bleeding, and pain. Therefore, noninvasive methods are urgently needed to avoid biopsy for diagnosing NAFLD. This review discusses the current noninvasive methods for assessing NAFLD, including steatosis, NASH, and NAFLD-related fibrosis, and explores the advantages and disadvantages of measurement tools. In addition, we analyze potential noninvasive biomarkers for tracking disease processes and monitoring treatment effects, and explore effective algorithms consisting of imaging and nonimaging biomarkers for diagnosing advanced fibrosis and reducing unnecessary biopsies in clinical practice.

Keywords: Nonalcoholic fatty liver disease, Nonalcoholic steatohepatitis, Steatosis, Fibrosis, Noninvasive evaluation

Core tip: Nonalcoholic fatty liver disease (NAFLD) is becoming a major public health issue worldwide. Currently, biopsy is the gold standard for the diagnosis of NAFLD, but it has well-known limitations including sampling errors and severe complications. Thus, noninvasive methods are best alterations to avoid the biopsy. Herein, the noninvasive methods currently available for the assessment of NAFLD in adults are discussed, and we further evaluate the advantages and disadvantages of different assessing tools. In addition, we also analyze the potential of noninvasive biomarkers and their application for tracking NAFLD progression and monitoring the treatment response.