Meta-Analysis
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 21, 2020; 26(23): 3304-3317
Published online Jun 21, 2020. doi: 10.3748/wjg.v26.i23.3304
Value of intravoxel incoherent motion in detecting and staging liver fibrosis: A meta-analysis
Zheng Ye, Yi Wei, Jie Chen, Shan Yao, Bin Song
Zheng Ye, Yi Wei, Jie Chen, Shan Yao, West China School of Medicine, Sichuan University, Chengdu 610041, Sichuan Province, China
Bin Song, Department of Radiology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
Author contributions: Ye Z contributed to the conception and design of the study, carried out acquisition, analysis, and interpretation of data, and drafted the article; Wei Y and Chen J interpreted the data and revised the article; Yao S carried out acquisition, analysis, and interpretation of data; Song B contributed to the conception and design of the study and final approval; All authors approved the final version of the article.
Supported by the National Nature Science Foundation of China, No. 81771797 and No. 81971571; and the 1.3.5 Project for Disciplines of Excellence, West China Hospital, Sichuan University, No. ZYJC18008.
Conflict-of-interest statement: The authors have no conflicts of interest to declare.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
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: Bin Song, PhD, Chief Doctor, Department of Radiology, West China Hospital, Sichuan University, No. 37 Guoxue Alley, Chengdu 610041, Sichuan Province, China. songb_radiology@163.com
Received: December 30, 2019
Peer-review started: December 30, 2019
First decision: February 18, 2020
Revised: March 26, 2020
Accepted: May 29, 2020
Article in press: May 29, 2020
Published online: June 21, 2020
Abstract
BACKGROUND

Liver fibrosis (LF) is a common pathological feature of all chronic liver diseases. With the accumulation of extracellular matrix in the fibrotic liver, true molecular water diffusion and perfusion-related diffusion are restricted. Intravoxel incoherent motion (IVIM) can capture the information on tissue diffusivity and microcapillary perfusion separately and reflect the fibrotic severity with diffusion coefficients.

AIM

To investigate the diagnostic performance of IVIM in detecting and staging LF with histology as a reference standard.

METHODS

A comprehensive literature search was conducted to identify studies on the diagnostic accuracy of IVIM for assessment of histologically proven LF. The stages of LF were classified as F0 (no fibrosis), F1 (portal fibrosis without septa), F2 (periportal fibrosis with few septa), F3 (septal fibrosis), and F4 (cirrhosis) according to histopathological findings. Data were extracted to calculate the pooled sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio, as well as the area under the summary receiver operating characteristic curve (AUC) in each group.

RESULTS

A total of 12 studies with 923 subjects were included in this meta-analysis with 5 studies (n = 465) for LF ≥ F1, 9 studies (n = 757) for LF ≥ F2, 4 studies (n = 413) for LF ≥ F3, and 6 studies (n = 562) for LF = F4. The pooled sensitivity and specificity were estimated to be 0.78 (95% confidence interval: 0.73-0.82) and 0.81 (0.74-0.86) for LF ≥ F1 detection with IVIM; 0.82 (0.79-0.86) and 0.80 (0.75-0.84) for staging F2 fibrosis; 0.85 (0.79-0.90) and 0.83 (0.77-0.87) for staging F3 fibrosis, and 0.90 (0.84-0.94) and 0.75 (0.70-0.79) for detecting F4 cirrhosis, respectively. The AUCs for LF ≥ F1, F2, F3, F4 detection were 0.862 (0.811-0.914), 0.883 (0.856-0.909), 0.886 (0.865-0.907), and 0.899 (0.866-0.932), respectively. Moderate to substantial heterogeneity was observed with inconsistency index (I2) ranging from 0% to 77.9%. No publication bias was detected.

CONCLUSION

IVIM is a noninvasive tool with good diagnostic performance in detecting and staging LF. Optimized and standardized IVIM protocols are needed to further improve its diagnostic accuracy in clinical practice.

Keywords: Liver fibrosis, Liver cirrhosis, Intravoxel incoherent motion, Diffusion weight imaging, Diffusion magnetic resonance imaging, Meta-analysis

Core tip: Intravoxel incoherent motion (IVIM) can separately evaluate the change of true molecular diffusion and perfusion-related diffusion caused by liver fibrosis (LF). This is the first meta-analysis to investigate the performance of IVIM for LF detection and staging with comprehensive diagnostic estimates. The results showed that IVIM is a valuable tool in noninvasively detecting and staging LF. However, field strength, the number and distribution of b-values, as well as the triggering methods affect the diagnostic accuracy. There is still a need to establish an optimized and standardized IVIM protocol for LF diagnosis in clinical practice.