Reproducibility of late gadolidium enhancement of atrial ablation scar

Methods Eleven patients with atrial fibrillation (AF, 4 persistent) underwent first time pulmonary vein isolation procedure. 3D LGE magnetic resonance imaging (1.5T Philips Ingenia) was performed at 3 months (91 ± 15 days) post ablation (scan 1), with a reproducibility scan three days later (scan 2). 3D LGE acquisitions were performed at 10, 20 and 30 min post gadolinium (Gd, 0.2 mmol/kg) (spatial resolution 1.3 × 1.3 × 4 mm, reconstructed to 0.6 × 0.6 × 2 mm). Scan 2 was performed 48-96 hours after the Scan 1. The left atrium (LA) was manually segmented and LGE enhancement projected onto the shell (maximum intensity projection technique). Each pulmonary vein (PV) was analysed by 4 independent observers. The percentage of scar encirclement of each PV was quantified visually between 0% (no scar) and 100% (complete encirclement of vein by scar). The LA shell was thresholded at 3.3 standard deviations above the blood pool mean.