This study involves people who have Crohn’s disease with a condition called perianal fistula, which is an abnormal connection or tunnel that forms near the area around the anus and is related to their Crohn’s disease. The study will compare two different contrast agents, which are special liquids injected into a vein to help make images clearer during scans. The two contrast agents being tested are gadopiclenol, which is found in a product called Elucirem, and gadobutrol, which is found in a product called Gadovist. Both of these substances contain a metal called gadolinium that helps doctors see internal body structures more clearly on scans.

The purpose of this study is to check if gadopiclenol works well for finding and tracking perianal fistulas when used during magnetic resonance imaging, which is also called MRI, a type of scan that uses magnets and radio waves to create detailed pictures of the inside of the body. Participants will receive both contrast agents at different times during the study, with each one being given through a vein before an MRI scan is performed. The study follows a crossover design, which means that each person will have scans with both contrast agents so that doctors can compare how well each one works in showing the fistula tract, which is the path or tunnel of the abnormal connection.

During the study, doctors will look at the MRI images to see how clearly they can identify the perianal fistula when each contrast agent is used. They will also measure technical aspects of the images, such as how much difference there is between the fistula and the healthy tissue around it, and how much the contrast agent brightens the fistula area compared to before it was given. This information will help determine if gadopiclenol is as effective as gadobutrol for this specific use in people with Crohn’s disease and perianal fistulas.