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.