Monitoring of Pediatric Inflammatory Bowel Diseases Using Multispectral Optoacoustic Tomography

In this clinical trial, the intestinal wall of pediatric patients with Crohns disease and Ulcerative Colitis will be assessed with multispectral optoacoustic tomography (MSOT) to characterize the optoacoustic signal of the intestinal wall and to monitor disease activity. The goal of this clinical trial is to compare the optoacoustic signal in the intestinal wall of children with inflammatory bowel diseases. The main questions it aims to answer are: * How does the optoacoustic signal in children with inflammatory bowel diseases change over time? * How does the optoacoustic signal in children with inflammatory bowel diseases change when they receive therapy? Participants will be examined with multispectral optoacoustic tomography.

In this study, the disease activity of children and adolescents with inflammatory bowel disease (IBD) will be assessed non-invasively by multispectral optoacoustic tomography (MSOT). IBDs play an important role in pediatric and adolescent medicine. The most common entities in the IBS group are Crohn's disease (CD) and ulcerative colitis (UC). Patients with CD develop chronic intermittent transmural inflammation of the gastrointestinal (GI) tract. Symptoms include diarrhea, hematochezia, abdominal pain, and malnutrition. Complications of the disease include fistula formation, perforations, and bleeding.The basis for many clinical decisions is the detection of disease activity.There are limitations to previous imaging methods for routine monitoring that are particularly relevant in pediatric and adolescent medicine.The use of contrast media, sedation, and invasive procedures are a burden for pediatric patients\*.Multispectral optoacoustic tomography (MSOT) offers a radiation-free and noninvasive alternative for detecting disease activity. Quantitative assessment of hemoglobin signal in the bowel wall of patients with CD could previously be correlated with endoscopically detected disease activity. The aim of this study is to evaluate whether MSOT also allows monitoring of chronic inflammatory diseases in children. For this purpose, children in different stages of disease who regularly receive intravenous therapeutic administrations of biologics (e.g. infliximab) in our hospital will be examined. The investigators think that by means of MSOT different stages and courses of the diseases could be measured non-invasively and thus invasive measures in children could be reduced.