Retrospective Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 21, 2019; 25(27): 3619-3633
Published online Jul 21, 2019. doi: 10.3748/wjg.v25.i27.3619
Quantitative diffusion-weighted magnetic resonance enterography in ileal Crohn's disease: A systematic analysis of intra and interobserver reproducibility
Hao Yu, Ya-Qi Shen, Fang-Qin Tan, Zi-Ling Zhou, Zhen Li, Dao-Yu Hu, John N Morelli
Hao Yu, Ya-Qi Shen, Fang-Qin Tan, Zi-Ling Zhou, Zhen Li, Dao-Yu Hu, Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
John N Morelli, St. John’s Medical Center, Tulsa, OK 74133, United States
Author contributions: Hu DY and Shen YQ designed the research; Yu H and Tan FQ performed the MR examinations; Yu H and Zhou ZL analyzed the data; Yu H wrote the paper; Morelli JN, Li Z, Shen YQ, and Hu DY revised the paper.
Supported by National Natural Science Foundation of China, No. 81571642, No. 81701657, and No. 81771801; and the Fundamental Research Funds for the Central Universities, No. 2017KFYXJJ126.
Institutional review board statement: This study was approved by the Ethics Committee of the Tongji Hospital of Huazhong University of Science and Technology.
Informed consent statement: Informed consent for this study was waived due to its retrospective nature.
Conflict-of-interest statement: All authors declare no conflict of interest related to this study.
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:
Corresponding author: Dao-Yu Hu, MD, PhD, Doctor, Professor, Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, Hubei Province, China.
Telephone: +86-13986297890 Fax: +86-27-83662640
Received: April 17, 2019
Peer-review started: April 17, 2019
First decision: May 9, 2019
Revised: May 20, 2019
Accepted: June 8, 2019
Article in press: June 8, 2019
Published online: July 21, 2019

Magnetic resonance enterography (MRE) is increasingly attractive as a noninvasive and radiation-free tool for assessing Crohn’s disease (CD). Diffusion-weighted imaging (DWI) is recommended as an optional MRE sequence for CD by the European Society of Gastrointestinal and Abdominal Radiology, and has shown a superb potential as a quantitative modality for bowel inflammation evaluation. However, the measurement reproducibility of quantitative DWI analysis in MRE has not been ascertained so far. To facilitate the application of quantitative diffusion-weighted MRE in the clinical routine, systematic investigations of the intra and interobserver reproducibility of DWI quantitative parameters should be performed.


To evaluate the intra and interobserver reproducibility of quantitative analysis for diffusion-weighted MRE (DW-MRE) in ileal CD.


Forty-four subjects (21 with CD and 23 control subjects) who underwent ileocolonoscopy and DW-MRE (b = 800 s/mm2) within one week were included. Two radiologists independently measured apparent diffusion coefficients (ADC) of the terminal ileum and signal intensity ratio (SR) of the terminal ileum to ipsilateral psoas muscle on DWI images (b = 800 s/mm2). Between- and within-reader agreements were assessed using intraclass correlation coefficients (ICC), coefficients of variation (CoV), and 95% limits of agreement of Bland-Altman plots (BA-LA LoA). Diagnostic performances of ADC and SR for identifying inflamed terminal ileum from the normal were evaluated by receiver operating characteristic (ROC) curve analysis.


There were no significant differences in ADC or SR values between the two sessions or between the two radiologists either in the CD or control group (paired t-test, P > 0.05). The intra and interobserver reproducibility of ADC (ICC: 0.952-0.984; CoV: 3.73-6.28%; BA-LA LoA: ±11.27% to ±15.88%) and SR (ICC: 0.969-0.989; CoV: 3.51%-4.64%; BA-LA LoA: ±10.62% to ±15.45%) was excellent for CD. Agreement of ADC measurements was slightly less in control subjects (ICC: 0.641-0.736; CoV: 10.47%-11.43%; BA-LA LoA: ± 26.59% to ± 30.83%). SR of normal terminal ileum demonstrated high intra and interobserver reproducibility (ICC: 0.944-0.974; CoV: 3.73%-6.28%; BA-LA LoA: ± 18.58% to ± 24.43%). ADC and SR of two readers had outstanding diagnostic efficiencies (area under the ROC curve: 0.923-0.988).


Quantitative parameters derived from DW-MRE have good to excellent intra and interobserver agreements with high diagnostic accuracy, and can serve as robust and efficient quantitative biomarkers for CD evaluation.

Keywords: Magnetic resonance imaging, Diffusion-weighted imaging, Crohn's disease, Ileum, Reproducibility

Core tip: We evaluated the measured reproducibility of quantitative apparent diffusion coefficients (ADC) and signal contrast ratio (SR) of the terminal ileum to ipsilateral psoas muscle on diffusion-weighted imaging (DWI; b = 800 s/mm2). The intra and interobserver reproducibility of ADC and SR values was good to excellent for Crohn’s disease (CD) and normal control subjects. Quantitative parameters of ADC and SR derived from DWI had outstanding diagnostic efficacy for CD. Therefore, both ADC and SR could serve as robust and efficient quantitative biomarkers for the evaluation of CD.