Editorial
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 21, 2015; 21(15): 4432-4439
Published online Apr 21, 2015. doi: 10.3748/wjg.v21.i15.4432
Noninvasive imaging assessment of non-alcoholic fatty liver disease: Focus on liver scintigraphy
Cristiane Valle Tovo, Angelo Zambam de Mattos, Gabriela Perdomo Coral, Fernanda Schild Branco, Eiji Suwa, Angelo Alves de Mattos
Cristiane Valle Tovo, Angelo Zambam de Mattos, Gabriela Perdomo Coral, Fernanda Schild Branco, Eiji Suwa, Angelo Alves de Mattos, Department of Gastroenterology and Hepatology, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre 90430-080, Brazil
Author contributions: Tovo CV and de Mattos AA conceptualized the manuscript; Tovo CV, de Mattos AZ, Coral GP and Branco FS wrote the paper; de Mattos AA and Suwa E performed the final review of the manuscript with significant contributions; all authors approved the final version of the manuscript.
Conflict-of-interest: The authors have no conflicts of interest to declare.
Open-Access: This article is an open-access article which 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: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Cristiane Valle Tovo, MD, PhD, Department of Gastroenterology and Hepatology, Universidade Federal de Ciências da Saúde de Porto Alegre, Rua Cel Aurélio Bitencourt 115 apto 201, Porto Alegre 90430-080, Brazil. cris.tovo@terra.com.br
Telephone: +55-51-32148158 Fax: +55-51-32148158
Received: November 18, 2014
Peer-review started: November 18, 2014
First decision: January 22, 2015
Revised: February 2, 2015
Accepted: March 18, 2015
Article in press: March 19, 2015
Published online: April 21, 2015
Abstract

Noninvasive diagnoses of nonalcoholic fatty-liver disease (NAFLD) involve the use of serologic markers and imaging methods, such as conventional ultrasonography (US), computed tomography, and magnetic resonance imaging. Although these methods are reliable for the noninvasive detection of moderate to severe fatty changes in the liver, they are not reliable for detecting nonalcoholic steatohepatitis (NASH) and fibrosis. New imaging technologies, such as US-based transient elastography, acoustic radiation force impulse and magnetic resonance-based elastography, can reportedly be used to determine the severity of liver fibrosis associated with NASH. In this context, the field of nuclear medicine through liver scintigraphy has recently been proposed, and is being explored for use in the diagnosis of NASH. More importantly, nuclear medicine may contribute to the distinction between simple steatosis and NASH. For example, the enhanced release of cytokines and the decrease in the phagocytic activity of Kupffer cells play important roles in the pathogenesis of NASH. Removal of technetium-99m colloid from circulation by Kupffer cell phagocytosis therefore provides a valuable imaging technique. Thus, nuclear medicine is poised to provide useful tools for the evaluation of patients with NAFLD. However, the evidence is still scarce, and more studies with larger samples are needed to identify their role before they are used in clinical practice.

Keywords: Liver fibrosis, Liver scintigraphy, Nonalcoholic fatty-liver disease diagnosis, Nonalcoholic steatohepatitis, Noninvasive methods

Core tip: Noninvasive methods used to diagnosis nonalcoholic fatty-liver disease (NAFLD) include ultrasonography (US), computed tomography, and magnetic resonance imaging. Although these methods are reliable for the noninvasive detection of moderate to severe fatty changes in the liver, they are not reliable for detecting nonalcoholic steatohepatitis and fibrosis. New imaging technologies, such as US-based transient elastography, acoustic radiation force impulse and magnetic resonance-based elastography, may be used to determine the severity of liver fibrosis. Liver scintigraphy has recently been proposed to evaluate the diagnosis of nonalcoholic steatohepatitis, and has potential for the evaluation of patients with NAFLD.