Progression And Variability Of Tnbs Colitis-Associated Inflammation In Rats Assessed By Contrast-Enhanced And T2-Weighted Mri

Background: A common feature of preclinical models of colitis is that the time-course. magnitude, and persistence of inflammation vary considerably within the experimental animal group. Accordingly. noninvasive, serial quantification of colonic inflammation Could advantageously guide dosing regimens and assess drug, efficacy, thus enhancing the value of colitis models in research. This investigation using magnetic resonance imaging (MRI) was therefore undertaken to objectively determine inflammatory progression, variability, and response to therapy associated with trinitrobenzene sulfonic acid (TNBS)-induced colitis in Wistar rats.Methods: Rats underwent TNBS treatment oil Day and received sulfasalazine or vehicle (methylcellulose) orally daily, from Day - 1 (prophylactically) or Day 2 (therapeutically). T2-weighted and semidynamic T1-weighted contrast-enhanced MRI (CE-MRI) was repeated over 7-10 clays to measure colon wall thickness and perfusion-related aspects of inflammation. Rectal bleeding. stool consistency, and disease activity were scored throughout and colon pathology determined terminally.Results: Principal component analysis of the CE-MRI time-series highlighted colon wall and mesenteric inflammation, which increased by 6-8X naive Values. Peristaltic artifacts were distinguished from perfusion changes using the normalized temporal standard deviation. MRI correlated strongly with terminal colon weight (mean correlation r = 0.8). well with body weight change (r = -0.7), but little with conventional Clinical Scores. Sulfasalazine reduced inflammation administered prophylactically and therapeutically.Conclusions: Inflammation and therapeutic efficacy call be sensitively quantified noninvasively using MRI in TNBS-treated rats. Objective in vivo measures This methodology provides unique and objective in vivo measures Of inflammation that Call guide closing strategies, enhancing colitis research effectiveness and the assessment of potential IBD therapeutics.