Heart Catheterization Using Magnetic Resonance Imaging (MRI) Fluoroscopy and Passive Guidewires

Heart catheterization is a minimally invasive procedure to measure pressure into specific heart cavities. Heart catheterization usually uses X-ray guidance, which involves radiation exposure, and which fails to visualize soft tissue. For several years, real-time magnetic resonance imaging (MRI) fluoroscopy has been the standard technique to guide right heart catheterization at the NIH clinical center. Guidewires are standard tools used to steer catheters through the body and heart. Guidewires have not been used during MRI fluoroscopy catheterization because of the risk of heating. We have developed MRI techniques that do not risk heating using specific commercial guidewires. In this protocol we will use this new low-energy real-time MRI fluoroscopy technique to enable use of guidewires during otherwise standard MRI catheterization of the right side of the heart through veins, and of the left side of the heart through the aorta. In the second phase of the protocol, we will begin performing systematic MRI guidewire heart catheterization without X-ray whenever possible. We will assess the heart s response to hemodynamic provocation during MRI catheterization tailored to the patient s problem. We will use this protocol to further refine the technique. This will enable future testing of devices for adult and pediatric MRI-fluoroscopy catheterization, which may lead to new non-surgical treatments of cardiovascular disease.