Enhancement quality at imaging centres. Variation in enhancement quality: Enhancement normalisation in images (n = 60) from all three centres supplied for the challenge in pre-ablation (left) and post-ablation (right) LGE CMR. The histograms plot enhanced pixels in the consensus segmentation. Intensities are normalised to atrial blood pool mean. Horizontal axes represents intensity in enhancement as standard deviations (SD) from blood-pool mean. Increasing enhancement corresponds to increasing SD.