Retrospective Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Feb 7, 2019; 25(5): 622-631
Published online Feb 7, 2019. doi: 10.3748/wjg.v25.i5.622
Hepatocellular carcinoma: Can LI-RADS v2017 with gadoxetic-acid enhancement magnetic resonance and diffusion-weighted imaging improve diagnostic accuracy?
Tong Zhang, Zi-Xing Huang, Yi Wei, Han-Yu Jiang, Jie Chen, Xi-Jiao Liu, Li-Kun Cao, Ting Duan, Xiao-Peng He, Chun-Chao Xia, Bin Song
Tong Zhang, Zi-Xing Huang, Yi Wei, Han-Yu Jiang, Jie Chen, Xi-Jiao Liu, Li-Kun Cao, Ting Duan, Xiao-Peng He, Chun-Chao Xia, Bin Song, Department of Radiology, Sichuan University West China Hospital, Chengdu 610041, Sichuan Province, China
Author contributions: Zhang T, Wei Y, and Song B designed the research; Zhang T, Huang ZX, Jiang HY, and Chen J conducted literature search and analysis; Liu XJ, Cao Lk, Duan T, He XP, and Xia CC provided material support; Song B provided funding for the article; Zhang T and Huang ZX wrote the paper.
Supported by National Natural Science Foundation of China, No. 81471658; and Science and Technology Support Program of Sichuan Province, No. 2017SZ0003.
Institutional review board statement: This study was approved by the Ethics Committee of West China Hospital.
Informed consent statement: Patients were not required to give informed consent to the study because this retrospective study used anonymous clinical data that were obtained after each patient agreed to treatment by written consent.
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 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: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Bin Song, MD, Chief Doctor, Doctor, Professor, Department of Radiology, Sichuan University West China Hospital, No. 37, Guoxue Alley, Chengdu 610041, Sichuan Province, China. anicesong@vip.sina.com
Telephone: +86-28-85423680 Fax: +86-28-85582499
Received: October 19, 2018
Peer-review started: October 19, 2018
First decision: December 20, 2018
Revised: December 25, 2018
Accepted: January 14, 2019
Article in press: January 14, 2019
Published online: February 7, 2019
Processing time: 103 Days and 2.7 Hours
ARTICLE HIGHLIGHTS
Research background

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cause of cancer-related deaths. The Liver Imaging Reporting and Data System (LI-RADS), supported by the American College of Radiology (ACR), has been developed for standardizing the acquisition, interpretation, reporting, and data collection of liver imaging examinations in patients at risk for HCC. Ancillary features can be applied to upgrade or downgrade the initially assigned LI-RADS category based on major features only.

Research motivation

Magnetic resonance imaging (MRI) can be used for categorization of liver observations and diagnosis of HCC based on the major and ancillary features of LI-RADS. Gadoxetic-acid disodium (Gd-EOB-DTPA), a hepatobiliary contrast agent, could provide information of hepatocyte function. Diffusion-weighted imaging (DWI) can further quantitatively measure tissue diffusion and further reflect tumor cellularity. Thus, the combination of Gd-EOB-DTPA-enhanced MRI and DWI has the potential to improve the diagnostic accuracy (AC) for HCC.

Research objectives

In this study, we aimed to determine the usefulness of DWI in improving the diagnostic AC of LI-RADS v2017 classification. In addition, future research should focus on the comparison of LI-RADS v2017 and v2018.

Research methods

In this institutional review board-approved study, a total of 414 consecutive patients at high risk for HCC were enrolled. Two radiologists who were blinded to the clinical, laboratory, and pathology results reinterpreted the MR images. Each reader measured the maximum diameter and recorded the presence of each lesion and assigned scores according to LI-RADS v2017. The ancillary feature “restricted diffusion” on DWI images could be used at radiologist discretion for category adjustment (upgrade or downgrade). The kappa test was used to determine the agreement between the two independent radiologists in each item. In addition, the sensitivity (SE), specificity (SP), AC, positive predictive value (PPV), and negative predictive value (NPV) were calculated for assessing the diagnostic performance of LI-RADS. Youden index values were used to compare the diagnostic performance of LI-RADS with or without DWI.

Research results

For LR-5, the diagnostic SE, SP, and AC values were 61.2%, 92.5%, and 71.4%, respectively, with or without DWI; for LR-4/5, they were 73.9%, 80%, and 75.9% without DWI and 87.9%, 80%, and 85.3% with DWI; for LR-4/5/M, they were 75.8%, 58.8%, and 70.2% without DWI and 87.9%, 58.8%, and 78.4% with DWI; for LR- 4/5/TIV, they were 75.8%, 75%, and 75.5% without DWI and 89.7%, 75%, and 84.9% with DWI. The Youden index values of the LI-RADS classification without or with DWI were as follows: LR-4/5: 0.539 vs 0.679; LR-4/5/M: 0.346 vs 0.467; and LR-4/5/TIV: 0.508 vs 0.647. The remaining problems that exist should be solved by using prospective, multi-center study to verify our results.

Research conclusions

The ancillary feature “restricted diffusion” on DWI images could be used at radiologist discretion for category adjustment (upgrade or downgrade). The ability of DWI is to reflect the cellularity of tissue. Compared with normal tissue, tumor tissue with high cellularity could result in decreased extracellular space and limited water diffusion, represented by high signal intensity. In our study, a small number of lesions were classified as LR-3 without DWI; however, when DWI was added, these lesions were downgraded to LR-2 due to unrestricted diffusion. In addition, some lesions previously classified as LR-3 were upgraded to LR-4 due to restricted diffusion. Thus, our study also shows that the use of DWI can improve the diagnostic efficiency of LI-RADS v2017 with gadoxetic acid-enhanced MRI for HCC. We believe that our data, a pool of categorization results by several readers during actual MRI interpretation, can better be explained by clinical practice and may be broadly applied.

Research perspectives

Our study shows that LI-RADS v2017 has been successfully applied with gadoxetate-enhanced MRI for patients at high risk for HCC. The addition of DWI significantly increased the diagnostic efficiency for HCC. For the future research, we intend to investigate interobserver or intraobserver variability through a multi-center study and apply the latest 2018 version of LI-RADS.