The Role of PET/MRI in the Diagnosis and Treatment of Children and Adolescents With Inflammatory Bowel Diseases

Accuracy of PET/MRI in Diagnosis and Treatment Evaluation of Children and Adolescents With Inflammatory Bowel Disease

The purpose of this study is to test the utility of PET/MRI in diagnosis and management of Inflammatory bowel disease (IBD) in children and adolescents, hereby

• To test if PET/MRI scan is an accurate method to diagnose and differentiate Crohn's disease and Ulcerous Colitis in children and adolescents suspected of IBD.
• To evaluate whether PET/MRI scan in children and adolescents with Crohn's disease is an accurate method to diagnose relapses and to monitor the effect of biological treatment with monoclonal antibodies directed towards Tumor Necrosis Factor-alpha.

Crohn's disease and Ulcerous Colitis constitute the primary inflammatory bowel diseases. Crohn's disease can affect any part of the digestive tract, from mouth to anus, and inflammation can be present in all layers of the intestinal wall. Ulcerous Colitis is primarily located in the inner layer of the colonic bowel wall.

In the pediatric population, current diagnostic strategies involve blood tests, fecal sampling (calprotectin), magnetic resonans (MRI) scan and both upper and lower endoscopies. In this population endoscopy requires general anesthesia and involves the risk of bowel wall perforation.

A known method of identifying inflammation is by Positron Emission Tomography (PET). In this procedure a radioactively labelled sugar molecule is injected into the blood stream via a venous catheter. The inflammatory cells take op relatively more of the sugar, compared to normal cells, and the cells are visible on the scan. Until now the anatomic localization of the inflammation has been poor but recently is has become possible to combine the MRI scan with PET resulting in excellent localization, with minimal radiation exposure (corresponding to 1 year background radiation in Denmark).

To make diagnosis and identification of inflammation flares during treatment safer for children and adolescents we aim to investigate whether PET/MRI is accurate in diagnosing IBD in children and adolescents and in diagnosing flares in children with Crohn's disease.

Inclusion Criteria:

• Suspected of having IBD
• Planned to undergo standard evaluation OR
• Known Crohn's disease about to start anti-TNF therapy due to steroid dependency or disease relapse.

Exclusion Criteria:

• Active or prior diagnosis of inflammatory disease other than IBD
• Active or prior diagnosis of cancer
• Type 1 diabetes
• Not able to lie still for the MRI scan.