Retrospective Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Surg. May 27, 2023; 15(5): 882-891
Published online May 27, 2023. doi: 10.4240/wjgs.v15.i5.882
Diagnostic performance of texture analysis in the differential diagnosis of perianal fistulising Crohn’s disease and glandular anal fistula
Xin Zhu, Dan-Dan Ye, Jian-Hua Wang, Jing Li, Shao-Wei Liu
Xin Zhu, Jian-Hua Wang, Jing Li, Shao-Wei Liu, Department of Radiology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing 210029, Jiangsu Province, China
Dan-Dan Ye, Department of Radiology, Quanzhou Orthopedic-Traumatological Hospital, Quanzhou 362000, Fujian Province, China
Author contributions: Zhu X designed the research study; Ye DD, Li J, and Liu SW performed the research; Zhu X and Wang JH analyzed the data and wrote the manuscript; All authors have read and approve the final manuscript.
Institutional review board statement: This study was approved by the institutional review board of the Affiliated Hospital of Nanjing University of Chinese Medicine; informed consent was waived owing to the retrospective nature of the study.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Data sharing statement: All datasets generated for this study are included in the manuscript and/or the supplementary files.
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: Xin Zhu, Doctor, MD, Chief Doctor, Department of Radiology, Affiliated Hospital of Nanjing University of Chinese Medicine, No. 155 Hanzhong Road, Nanjing 210029, Jiangsu Province, China. zhuxin-njcm@njucm.edu.cn
Received: December 12, 2022
Peer-review started: December 12, 2022
First decision: January 2, 2023
Revised: January 16, 2023
Accepted: March 30, 2023
Article in press: March 30, 2023
Published online: May 27, 2023
Abstract
BACKGROUND

Perianal fistulising Crohn's disease (PFCD) and glandular anal fistula have many similarities on conventional magnetic resonance imaging. However, many patients with PFCD show concomitant active proctitis, but only few patients with glandular anal fistula have active proctitis.

AIM

To explore the value of differential diagnosis of PFCD and glandular anal fistula by comparing the textural feature parameters of the rectum and anal canal in fat suppression T2-weighted imaging (FS-T2WI).

METHODS

Patients with rectal water sac implantation were screened from the first part of this study (48 patients with PFCD and 22 patients with glandular anal fistula). Open-source software ITK-SNAP (Version 3.6.0, http://www.itksnap.org/) was used to delineate the region of interest (ROI) of the entire rectum and anal canal wall on every axial section, and then the ROIs were input in the Analysis Kit software (version V3.0.0.R, GE Healthcare) to calculate the textural feature parameters. Textural feature parameter differences of the rectum and anal canal wall between the PFCD group vs the glandular anal fistula group were analyzed using Mann-Whitney U test. The redundant textural parameters were screened by bivariate Spearman correlation analysis, and binary logistic regression analysis was used to establish the model of textural feature parameters. Finally, diagnostic accuracy was assessed by receiver operating characteristic-area under the curve (AUC) analysis.

RESULTS

In all, 385 textural parameters were obtained, including 37 parameters with statistically significant differences between the PFCD and glandular anal fistula groups. Then, 16 texture feature parameters remained after bivariate Spearman correlation analysis, including one histogram parameter (Histogram energy); four grey level co-occurrence matrix (GLCM) parameters (GLCM energy_all direction_offset1_SD, GLCM entropy_all direction_ offset4_SD, GLCM entropy_all direction_offset7_SD, and Haralick correlation_all direction_ offset7_SD); four texture parameters (Correlation_all direction_offset1_SD, cluster prominence _angle 90_offset4, Inertia_all direction_offset7_SD, and cluster shade_angle 45_offset7); five grey level run-length matrix parameters (grey level nonuniformity_angle 90_offset1, grey level nonuniformity_all direction_offset4_SD, long run high grey level emphasis_all direction_offset1_SD, long run emphasis_all direction_ offset4_ SD, and long run high grey level emphasis_all direction_offset4_SD); and two form factor parameters (surface area and maximum 3D diameter). The AUC, sensitivity, and specificity of the model of textural feature parameters were 0.917, 85.42%, and 86.36%, respectively.

CONCLUSION

The model of textural feature parameters showed good diagnostic performance for PFCD. The texture feature parameters of the rectum and anal canal in FS-T2WI are helpful to distinguish PFCD from glandular anal fistula.

Keywords: Anal fistula, Crohn’s diseases, Magnetic resonance imaging, Texture analysis, Differential diagnosis

Core Tip: Crohn's disease (CD) is a localized, segmental chronic granulomatous inflammation that can affect the digestive tract from the oral cavity to the anus, and its pathophysiology is non-caseous necrotic granuloma. Nearly 10% of patients with CD have an anal fistula before presenting gastrointestinal symptoms. At the same time, perianal fistulising CD (PFCD) and glandular anal fistula have many similarities on conventional magnetic resonance imaging (MRI); therefore, it is difficult to differentiate between these conditions in the early stages with conventional MRI. Texture analysis based on conventional MRI images can quantitatively analyze image pixel information and reflect the internal heterogeneity and pathological characteristics of the lesion. Currently, this approach is widely used to distinguish between benign and malignant tumors, predict tumor stage, and evaluate treatment efficacy. In addition to the application of texture analysis in the study of tumors or substantial organs, some studies have applied texture analysis to hollow organs such as the intestine. Many patients with PFCD show concomitant active proctitis, but only few patients with glandular anal fistula have active proctitis. Based on this theory, we analyzed the texture of the rectum and anal canal wall in the PFCD group and glandular anal fistula group in this study to explore whether the texture feature parameters are valuable in identifying and differentiating these two lesions.