MRI Characterization of Tissue Injury Progression After Atrial Fibrillaton Ablation

Introduction: Characterization of ablation lesion could help guide procedures by identifying viable tissue and scar gaps. In this study we showed MRI characterization of atrial tissue injury progression from catheter touch down to three months post ablation. Methods: Fifty patients underwent AF ablation under electro-anatomical guidance. Each patient was taken to a 3T MRI scanner immediately after ablation. High resolution LGE-MRI images of the left atrium (LA) were acquired 15 minutes after contrast injection. In addition, ten pigs were ablated in a 3T real-time MRI suite during scanning and T2 weighted and LGE-MRI images obtained during and immediately post-ablation respectively. Results: T2w HASTE images showed enhancement during ablation, initially in the area of RF delivery followed by spatial extension beyond this area. T2w enhancement was seen as early as 10–15 seconds post ablation. LGE-MRI imaging immediately post ablation often showed dark, non-enhancing regions of ablated tissue (Figure 3, A1-A...