Fig. 1

High Spectrum Signal Intensity Coefficient (HS-SIC) analysis method. We analyzed parasternal long axis views acquired with routine protocols. We used ImageJ (v1.53, National Institutes of Health, Bethesda, MD) to select a 5 × 30 pixel region of interest (ROI) at the myocardial-pericardial interface along the inferolateral wall during end-diastole and aligned with at the level of the mitral leaflet tips. We then applied an image analysis macro to quantify the distribution of intensity values within the ROI, ranging from 0 to 256. Values were normalized and integrated across the 50th, 60th, 70th, 80th, and 90th percentiles of signal intensity to generate the HS-SIC