Catheter-Based Endomyocardial Injection With Real-Time Magnetic Resonance Imaging

Background—We tested the feasibility of targeted left ventricular (LV) mural injection using real-time MRI (rtMRI). Methods and Results—A 1.5T MRI scanner was customized with a fast reconstruction engine, transfemoral guiding catheter–receiver coil (GCC), MRI-compatible needle, and tableside consoles. Commercial real-time imaging software was customized to facilitate catheter navigation and visualization of injections at 4 completely refreshed frames per second. The aorta was traversed and the left ventricular cavity was entered under direct rtMRI guidance. Pigs underwent multiple injections with dilute gadolinium-DTPA. All myocardial segments were readily accessed. The active GCC and the passive Stiletto needle injector were readily visualized. More than 50 endomyocardial injections were performed with the aid of rtMRI; 81% were successful with this first-generation prototype. Conclusion—Percutaneous endomyocardial drug delivery is feasible with the aid of rtMRI, which permits precise 3-dimensional localization of injection within the LV wall.