Retrospective Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 21, 2018; 24(27): 3013-3020
Published online Jul 21, 2018. doi: 10.3748/wjg.v24.i27.3013
Liver intravoxel incoherent motion diffusion-weighted imaging for the assessment of hepatic steatosis and fibrosis in children
Hyun Joo Shin, Haesung Yoon, Myung-Joon Kim, Seok Joo Han, Hong Koh, Seung Kim, Mi-Jung Lee
Hyun Joo Shin, Haesung Yoon, Myung-Joon Kim, Mi-Jung Lee, Department of Radiology, Severance Hospital, Severance Pediatric Liver Disease Research Group, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul 03722, South Korea
Seok Joo Han, Department of Surgery, Severance Hospital, Severance Pediatric Liver Disease Research Group, Yonsei University College of Medicine, Seoul 03722, South Korea
Hong Koh, Seung Kim, Division of Gastroenterology, Hepatology and Nutrition, Department of Pediatrics, Severance Children’s Hospital, Severance Pediatric Liver Disease Research Group, Yonsei University College of Medicine, Seoul 03722, South Korea
Author contributions: Shin HJ and Lee MJ designed the research; Shin J, Yoon H, and Lee MJ performed the research and wrote the manuscript; Shin HJ, Yoon H and Lee MJ analyzed the data; Kim MJ, Han SJ, Koh H, and Kim S contributed analytic tools; Kim MJ, Shin HJ, Yoon H, Han SJ, Koh H, Kim S, and Lee MJ revised and approved the final version.
Institutional review board statement: This study was reviewed and approved by the local ethics committee of the Severance Hospital, Yonsei University (register no. 1-2017-0014).
Informed consent statement: Because of the retrospective and anonymous character of this study, the need for informed consent was waived by the institutional review board.
Conflict-of-interest statement: All authors declare no conflicts-of-interest related to this article.
Data sharing statement: No additional data are available.
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: Mi-Jung Lee, MD, PhD, Assistant Professor, Department of Radiology, Severance Hospital, Severance Pediatric Liver Disease Research Group, Research Institute of Radiological Science, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, South Korea. mjl1213@yuhs.ac
Telephone: +82-2-22287400 Fax: +82-2-3933035
Received: March 16, 2018
Peer-review started: March 17, 2018
First decision: April 24, 2018
Revised: April 26, 2018
Accepted: June 9, 2018
Article in press: June 9, 2018
Published online: July 21, 2018
Processing time: 124 Days and 16.2 Hours
Abstract
AIM

To evaluate the correlation between intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) parameters and the degree of hepatic steatosis and fibrosis in children.

METHODS

This retrospective study was approved by the institutional review board. The children (≤ 18 years) who underwent liver IVIM DWI with 8 b-values under the suspicion of hepatic steatosis or fibrosis from February 2013 to November 2016 were included. Subjects were divided into normal, fatty liver (FAT), and fibrotic liver (FIB) groups. The slow diffusion coefficient (D), fast diffusion coefficient (D*), perfusion fraction (f), and apparent diffusion coefficient (ADC) were measured. MR proton density fat fraction (PDFF), MR elastography (MRE), and IVIM values were compared.

RESULTS

A total of 123 children (median age of 12 years old, range: 6-18 years) were included, with 8 in the normal group, 93 in the FAT group, and 22 in the FIB group. The D* values were lower in the FIB group compared with those of the normal (P = 0.015) and FAT (P = 0.003) groups. The f values were lower in the FIB group compared with the FAT group (P = 0.001). In multivariate analyses, PDFF value was positively correlated with f value (β = 3.194, P < 0.001), and MRE value was negatively correlated with D* value (β = -7.031, P = 0.032). The D and ADC values were not influenced by PDFF or MRE value.

CONCLUSION

In liver IVIM DWI with multiple b-values in children, there was a positive correlation between hepatic fat and blood volume, and a negative correlation between hepatic stiffness and endovascular blood flow velocity, while diffusion-related parameters were not affected.

Keywords: Intravoxel incoherent motion; Diffusion-weighted imaging; Fibrosis; Fatty liver; Pediatrics

Core tip: Liver intravoxel incoherent motion (IVIM) diffusion-weighted imaging with multiple b-values was feasible and useful for evaluating hepatic steatosis and fibrosis in children. Hepatic steatosis and fibrosis affected IVIM parameters differently in children. MR proton density fat fraction (PDFF) demonstrated a positive correlation with the perfusion fraction (f) of IVIM. MR elastography (MRE) value was negatively correlated with the fast diffusion coefficient (D*) of IVIM. The other IVIM values were not influenced by PDFF or MRE value.