Observational Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 7, 2023; 29(21): 3318-3327
Published online Jun 7, 2023. doi: 10.3748/wjg.v29.i21.3318
Artifacts in two-dimensional shear wave elastography of liver
Hui-Peng Wang, Peng-Chao Zheng, Xue-Mei Wang, Liang Sang
Hui-Peng Wang, Peng-Chao Zheng, Xue-Mei Wang, Liang Sang, Department of Ultrasound, The First Hospital of China Medical University, Shenyang 110001, Liaoning Province, China
Author contributions: Wang HP and Sang L designed the research study; Wang HP and Zheng PC performed the research; Wang HP and Wang XM collected and analyzed the data; Wang HP and Sang L wrote the manuscript; all authors reviewed and approved the manuscript.
Institutional review board statement: The study was approved by the Institutional Ethical Review Board of The First Hospital of China Medical University (Approval No. AF-SOP-07-1.1-01).
Informed consent statement: All patients provided written informed consent prior to study enrollment.
Conflict-of-interest statement: The authors of this manuscript having no conflicts of interest to disclose.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Open-Access: This article 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 NonCommercial (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: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Liang Sang, MD, PhD, Associate Professor, Doctor, Department of Ultrasound, The First Hospital of China Medical University, No. 155 Nanjing North Street, Shenyang 110001, Liaoning Province, China. 13889167622@163.com
Received: February 27, 2023
Peer-review started: February 27, 2023
First decision: March 14, 2023
Revised: March 23, 2023
Accepted: May 6, 2023
Article in press: May 6, 2023
Published online: June 7, 2023
Research background

Chronic liver disease is a growing problem worldwide. Accurate assessment of liver fibrosis is important for treatment prioritization, surveillance, and determination of prognosis. Liver biopsy is still considered as the gold standard for staging liver fibrosis. However, liver biopsy is an expensive and invasive diagnostic tool. Its main complications are bleeding and pain, which limit its clinical application. Recently, the application of two-dimensional shear wave elastography (2-D SWE) in the diagnosis of non-invasive assessment of liver fibrosis has developed rapidly. However, the presence of artifacts leads to inaccurate liver stiffness (LS) measurements.

Research motivation

Although 2-D SWE artifacts of the liver are common in clinical practice, they are poorly recognized, and there is even no clear definition. To the best of our knowledge, only a few review articles have been published. Knowledge of the artifacts is essential to improve operation technology to obtain high-quality images. It is very important to obtain accurate measurements in an attempt to optimize its performance and application value.

Research objectives

We aim to investigate the presence and influence of artifacts in 2-D SWE of liver.

Research methods

In this study, we performed 2-D SWE examination in patients with chronic liver disease by a novice and an expert. The elastogram was divided into four locations: top-left, top-right, bottom-left, and bottom-right. The occurrence frequency of artifacts in different locations was compared. The effect of artifacts on the LS measurements was evaluated by comparing the elastogram with the most artifacts (EMA) and the elastogram with the least artifacts (ELA).

Research results

Each operator had 720 elastography images were included for analysis. The percentage of elastograms with artifacts and the area of artifacts in the novice were significantly higher than those in the expert (both P < 0.001). Comparing the occurrence frequency of artifacts in all locations of the two operators, it was found that both operators had the highest frequency of bottom-left, followed by top-left and bottom-right, and top-right had the lowest frequency. This study showed that the LS values and standard deviation values of the EMAs were higher than those of the ELAs. Both operators had lower stability index values and intraclass correlation coefficient values for EMAs than ELAs.

Research conclusions

Artifacts are common when using 2-D SWE to measure LS, especially for the novice. Our results showed artifacts were more likely to occur in the bottom-left corner of the elastogram. Artifacts may lead to the overestimation of LS and reduce the repeatability and reliability of LS measurements.

Research perspectives

In this study, we only analyzed a small sample of data from two operators of one device. Therefore, a larger sample study involving more operators and devices needs to be conducted in future studies.