Retrospective Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Mar 28, 2021; 27(12): 1182-1193
Published online Mar 28, 2021. doi: 10.3748/wjg.v27.i12.1182
R2* value derived from multi-echo Dixon technique can aid discrimination between benign and malignant focal liver lesions
Guang-Zi Shi, Hong Chen, Wei-Ke Zeng, Ming Gao, Meng-Zhu Wang, Hui-Ting Zhang, Jun Shen
Guang-Zi Shi, Hong Chen, Wei-Ke Zeng, Ming Gao, Jun Shen, Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, Guangdong Province, China
Meng-Zhu Wang, Hui-Ting Zhang, MR Scientific Marketing, Siemens Healthineers, Guangzhou 510120, Guangdong Province, China
Author contributions: Shi GZ and Chen H contributed equally to this work; Shi GZ and Shen J designed the research; Shi GZ, Chen H, Zeng WK, and Wang MZ collected and analyzed the data; Shi GZ wrote the manuscript; Shi GZ, Chen H, Zeng WK, Gao M, Wang MZ, and Zhang HT analyzed and interpreted the data; Shen J wrote and revised the manuscript; all co-authors participated in writing and checking the manuscript, and approved the submitted manuscript.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of Sun Yat-Sen Memorial Hospital.
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous clinical data that were obtained after each patient agreed to treatment by written consent.
Conflict-of-interest statement: The authors declare no conflict of interest.
Data sharing statement: No additional data are available.
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: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Jun Shen, MD, Doctor, Professor, Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 Yanjiang Road West, Guangzhou 510120, Guangdong Province, China. shenjun@mail.sysu.edu.cn
Received: November 20, 2020
Peer-review started: November 20, 2020
First decision: January 23, 2021
Revised: February 2, 2021
Accepted: February 25, 2021
Article in press: February 25, 2021
Published online: March 28, 2021
ARTICLE HIGHLIGHTS
Research background

It is essential to distinguish between benign and malignant focal liver lesions (FLLs), as this differentiation determines the individual’s prognosis and subsequent treatment strategy. Since the use of iodine and gadolinium-based contrast agents is contraindicated, imaging techniques without the need of contrast agents have been used to diagnose FFLs, including diffusion-weighted imaging, intravoxel incoherent motion, diffusion kurtosis imaging, and magnetic resonance elastography.

Research motivation

Imaging techniques without the need of contrast agents have shown mixed success with limited clinical application. R2* estimation is inversely related to partial tissue pressure of oxygen, and reflects the paramagnetism of the tumor tissue, which may be helpful to differentiate between benign and malignant FLLs.

Research objectives

To investigate whether R2* derived from multi-echo Dixon imaging can aid differentiating benign from malignant FLLs. The findings obtained can provide information for differential diagnosis of FLLs using R2*.

Research methods

This study retrospectively enrolled 73 patients with 108 benign or malignant FLLs. All patients underwent conventional abdominal magnetic resonance imaging and multi-echo Dixon imaging. The mean R2* values of lesions were measured using 2D region of interest (2D-ROI) and volume of interest (VOI) approaches. Mean R2* values were compared between benign and malignant FFLs using the nonparametric Mann–Whitney test. Receiver operating characteristic curve analysis was used to determine the diagnostic performance of R2* in differentiation between benign and malignant FFLs. The diagnostic performance of R2* measured by 2D-ROI and VOI approaches was compared.

Research results

The study included 30 benign and 78 malignant FLLs. Mean R2* was significantly higher for malignant than benign FFLs as measured by 2D-ROI (P < 0.001) and VOI (P < 0.001). The area under the curve (AUC) of R2* measured by 2D-ROI was 0.884 at a cut-off of 25.2/s, with a sensitivity of 84.6% and specificity of 80.0% for differentiating benign from malignant FFLs. R2* measured by VOI yielded a AUC of 0.875 at a cut-off of 26.7/s in distinguishing benign from malignant FFLs, with a sensitivity of 85.9% and specificity of 76.7%. The AUCs of R2* were not significantly different between the 2D-ROI and VOI methods. However, due to the relatively small sample size, a large population from multiple centers is needed for further validation of our findings.

Research conclusions

R2* derived from multi-echo Dixon imaging can aid in differentiation between benign and malignant FLLs. 2D-ROI and VOI methods do not affect the diagnostic performance of R2*.

Research perspectives

This study describes that R2* value derived from multi-echo Dixon imaging can aid in differentiation between benign and malignant FLLs. The multi-echo Dixon sequence is easy to perform and requires only a single breath-hold of 16 s to image the entire liver, which holds a good potential for clinical application.