Pranav Bhagirath

122 Chapter 6 instrumented with catheters and undergoing an ablation. In this particular scenario, even with the correct protocols in place, it is a challenging task to safely bring the patient outside the MR suite 31 . Therefore, defibrillation should be considered as a major issue which needs to be addressed prior to performing complex (ventricular) ablative procedures. CLINICAL PERSPECTIVE The benefits of iCMR including 3-dimensional guidance, tissue characterization and lack of radiation exposure over conventional fluoroscopic procedural guidance are the underlying rationale for researchers investigating the feasibility of iCMR ( Table 1 ). Despite the growing number of centers experimentingwith iCMR, the clinical translation remains a challenge. An important reason is the limited availability of MRI compatible devices (e.g. needles, guidewires, catheters, recording system) and they are currently available for investigational purposes, only. In the recent years, both active and passive devices have been developed and tested ( table 1 ). Although active devices might be prone to heating issues, they offer multiple benefits over passive devices, including 1) real time, device guided navigation 2) no artifact and loss of anatomical information in the surrounding tissue and 3) easy distinction (using color coding) between electrodes and different devices. Future trials should focus at the design and heating aspects to enable active device usage in human studies. Another major reason delaying clinical implementation is the comprehensive technical know-how required on both, the imaging and EP level. However, the fact that basic (human) ablation studies can already be performed successfully inside the MRI using passive devices, indicates that the initial (difficult) pioneering phase has come to an end 31 . The workflow (using commercial imaging sequences) and setup (MRI-compatible catheters and EP system) as described in this review has resulted in an increased interest from multiple institutions to explore iCMR for EP and ablation purposes. A well thought out implementation strategy is essential prior to considering a transition towards iCMR. It appears obvious to start with relatively simple procedures like right sided heart catheterization 49, 50 . This serves three important goals; 1) familiarizing and educating the assisting personnel about the safety issues of working in an MRI environment, 2) training the radiographer to better understand the requirements