3D visualization of LGE site
The method of the 3D visualization for the LGE site was as follows. First, the LA was segmented semi-manually by contouring the endocardial and epicardial borders of the atrium, including the PVs. Second, the mean value and SD of the voxel intensity was measured on the “healthy” LA wall where no hyper-enhanced areas in the LGE-MRI were involved. Third, a voxel intensity histogram analysis of the LA wall identified LGEs as intensities >2 SD on the “healthy” LA wall. Furthermore, the degree of the intensity was categorized by color-coded scaling (green: > 1SD: yellow: 2 – 3SD; and red: > 3SD). Finally, a 3D reconstruction of the color-coded LGE and volume-rendered LA and PV image generated from the CE-MRA were fused semi-automatically. The LGE site was defined as a site with a signal intensity of > 1SD.