Figure 1

The selection of myocardial regions with different signal intensities in a LGE-positive HCM patient. Image A represents a short axis LGE image of a HCM patient, showing extensive focal fibrosis in the myocardium (white areas). The maximum signal (max SI) was determined by drawing a small ROI in the core of the region with focal fibrosis. Image B, which is the identical CMR image as (A) but with a segmentation overlay, shows non-enhanced myocardium (SI <20% max SI), intermediate enhanced myocardium in yellow (>20 and <50% of max SI) and enhanced myocardium in red (SI >50% of max SI) using the thresholding algorithm. Image C, D, and E show manually drawn ROI’s on corresponding T1 maps for non-enhanced, intermediate enhanced, and enhanced myocardium, respectively. LGE = late gadolinium enhancement. SI = signal intensity. ROI = region of interest.