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©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jan 14, 2017; 23(2): 216-223
Published online Jan 14, 2017. doi: 10.3748/wjg.v23.i2.216
SPECT-computed tomography in rats with TNBS-induced colitis: A first step toward functional imaging
Rachel Marion-Letellier, Pierre Bohn, Romain Modzelewski, Pierre Vera, Moutaz Aziz, Charlène Guérin, Guillaume Savoye, Céline Savoye-Collet
Rachel Marion-Letellier, Charlène Guérin, Guillaume Savoye, INSERM Unit UMR1073, Rouen University and Rouen University Hospital, 76183 Rouen, France
Pierre Bohn, Romain Modzelewski, Pierre Vera, Céline Savoye-Collet, QUANTIF LITIS EA 4108, Rouen University and Rouen University Hospital, 76183 Rouen, France
Moutaz Aziz, Service d’Anatomo-pathologie, Rouen University Hospital, 76031 Rouen, France
Guillaume Savoye, Gastroenterology department, Rouen University Hospital, 76031 Rouen, France
Céline Savoye-Collet, Radiology department, Rouen University Hospital, 76031 Rouen, France
Author contributions: Marion-Letellier R, Guérin C performed the majority of laboratory experiments and participated equally in treatment of animals; Marion-Letellier R, Savoye G, Savoye-Collet C analyzed the data; Bohn P and Modzelewski R performed the SPECT-CT procedure and analyzed imaging data; Aziz M performed the histological study; Marion-Letellier R, Savoye G, Savoye-Collet C, Bohn P, Vera P designed and coordinated the research; Marion-Letellier R, Savoye G, Savoye-Collet C wrote the paper.
Institutional animal care and use committee statement: All of the procedures were performed according to the recommendations from the Comité d’Ethique Normandie en matière d’expérimentation animale (Rouen, France). Appropriate measures were taken to minimize the animals’ pain or discomfort.
Conflict-of-interest statement: We declare that we have no financial and personal relationships with other people or organizations that could inappropriately influence our work.
Data sharing statement: The technical appendix, statistical code and dataset are available from the first author Rachel Marion-Letellier at marion_rachel@hotmail.com. All the participants gave informed consent for data sharing.
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: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Rachel Marion-Letellier, PhD, INSERM Unit UMR1073, Rouen University and Rouen University Hospital, 22, Boulevard Gambetta, 76183 Rouen, France. marion_rachel@hotmail.com
Telephone: +33(0)235148245 Fax: +33(0)235148240
Received: July 11, 2016
Peer-review started: July 13, 2016
First decision: August 29, 2016
Revised: September 6, 2016
Accepted: September 28, 2016
Article in press: September 28, 2016
Published online: January 14, 2017
AIM
To assess the feasibility of SPECT-computed tomography (CT) in rats with trinitrobenzene sulfonic acid (TNBS)-induced acute colitis and confront it with model inflammatory characteristics.
METHODS
Colitis was induced in Sprague-Dawley rats by intrarectal injection of TNBS (n = 10) while controls received vehicle (n = 10). SPECT-CT with intravenous injection of 10 MBq of 67Ga-Citrate was performed at day 2. SPECT-CT criteria were colon wall thickness and maximal wall signal intensity. Laboratory parameters were assessed: colon weight:length ratio, colon cyclooxygenase-2 expression by western blot and histological inflammatory score.
RESULTS
Colon weight/length ratio, colon COX-2 expression and histological inflammatory score were significantly higher in the TNBS group than in the control group (P = 0.0296, P < 0.0001, P = 0.0007 respectively). Pixel max tend to be higher in the TNBS group than in the control group but did not reach statistical significance (P = 0.0662). Maximal thickness is significantly increased in the TNBS group compared to the control group (P = 0.0016) while colon diameter is not (P = 0.1904). Maximal thickness and colon diameter were correlated to colon COX-2 expression (P = 0.0093, P = 0.009 respectively) while pixel max was not (P = 0.22). Maximal thickness was significantly increased when inflammation was histologically observed (P = 0.0043) while pixel max and colon diameter did not (P = 0.2452, P = 0.3541, respectively).
CONCLUSION
SPECT-CT is feasible and easily distinguished control from colitic rats.
Core tip: Transsectional imaging such as magnetic resonance imaging are emerging to evaluate colonic inflammation but they do not allowed inflammation quantification. Functional imaging by SPECT-computed tomography (CT) could be interesting under quantification. This present study validates the use of SPECT in colitis models. We confronted SPECT-CT parameters to lab parameters and we found that maximal thickness was correlated to inflammatory parameters such as colon COX-2 expression or histological inflammatory score. Evaluating animal models may be important an important tool for preclinical studies in inflammatory bowel diseases models. It also allows optimizing the technique prior to patient contact.
