Radiation-free heart catheterization using MRI

Minimally invasive and catheter-based therapies are targeting increasingly complex pathologies. This agenda requires better procedural image guidance. Real time MRi guided cardiovascular intervention proposes to use the superb tissue imaging afforded by MRi as a surrogate for direct surgical visualization1,2. By providing multiple views and real time functional imaging without ionizing radiation exposure, MRi could guide traditional invasive diagnostic and interventional procedures and enable novel ones. The great promise of real time MRi is to provide some of the soft tissue visualization afforded by direct surgical exposure with reduced morbidity compared to X-ray catheter procedures. This comes at the expense of increased operational complexity, reduced temporal and spatial resolution, and limited availability of catheter devices that are safe and visible under MRi. For certain applications, these difficulties might be justified. Complex and prolonged procedures in children who are especially sensitive to long term toxicity from radiation exposure, is one example. new interventional alternatives to conventional open surgery are another. MRi also allows the operator more quickly to recognize and respond to iatrogenic injury, such as perforation. Most X ray catheters either are invisible or unacceptable for use during real-time MRi procedures. Metallic cores or braiding that impart catheter pushability and torquability cause imaging artifacts and obscure entire organs. Polymer only catheters are not visible unless modified and often lack requisite mechanical performance. We classify MRi catheters according to two categories. Passive MRi catheters are visible based on their intrinsic materials properties. active MRi catheters incorporate electronics exploited by the MRi system itself to enhance visibility. There are no commercially available [Quote]active[Quote] MRi catheters, although this is an intensive area of research. However, passive catheters are commercially available which have been safe for MRi in our preclinical experience. These catheters will be used in the protocol described below. We have installed and configured combined X ray MRi capability at CMC to be able to develop combined procedures for human use. We have installed real-time imaging and reconstructions suitable for this application 3 16. as described below Rationale for this protocol, our team Dr Hussain and Dr Greil has previously performed radiation free MRi guided heart catheterization as a clinical procedure at their previous institution KCL, London.