Evaluation of Quantitative Imaging Biomarkers in the DSS Colitis Model

Purpose: In humans, colonoscopy is the gold standard for the diagnosis of inflammatory changes of the colon wall. Aim of this study was the identification of less invasive imaging biomarkers in the dextran sodium sulfate (DSS) colitis model to provide additional information on transmural changes of the colon wall. Procedures: Colitis was induced in C57BL/6 mice by administration of 2, 3, and 4 % DSS over a period of 5 days. Colon wall thickness was measured using magnetic resonance imaging (MRI), ultrasound (US), and x-ray computed tomography (CT), gut inflammation by positron emission tomography/CT, and mucosal changes of the colon wall by colonoscopy. Colon samples were examined histologically. Results: MRI, CT, US, and histological data revealed increased colon wall thickness in DSStreated mice compared to healthy controls. Elevated 2-deoxy-2[18F]fluoro-D-glucose uptake and colonoscopy confirmed high inflammatory load in the guts of colitis mice. Conclusions: The established quantitative imaging readouts offer promising perspectives to develop new compounds and to translate these methods into the clinical setting. Key words: DSS, Mouse model, Colitis, Inflammatory bowel disease, Multimodal imaging Abbreviations: CT, Computed tomography; MRI, Magnetic resonance imaging; PET/CT, Positron emission tomography combined with computed tomography; US, Ultrasound imaging; SPECT, Single photon emission computed tomography; [18F]FDG, 2-deoxy-2-[18F]fluoro-Dglucose; DSS, Dextran sodium sulfate; IBD, Inflammatory bowel disease