It has been demonstrated that highly reflectile echoes (HREs) on standard echocardiograms may represent foci of myocardial fibrosis, calcification, or infiltration. A pilot study of the echocardiograms of premature infants by our group has indicated the presence of HREs in many stressed infants. We have subsequently shown that these HREs correspond to myocardial scarring or necrosis.
By studying normal two-dimensional echocardiograms and those with visually observed highly reflectile echoes (HREs), we have been able to develop echo-intensity ranges for normal neonatal myocardium and suspected foci of necrosis. An amplitude analysis of the intensity levels of these highly reflectile areas (HREs) in the echocardiogram has indicated that their mean intensity was significantly higher than the surrounding healthy myocardial areas. Significant correlation was found between these highly reflectile echo zones and calcified or necrotic tissue based on postmortem pathological examination.
An objective method of quantifying the ultrasonic reflection amplitude has thereby been developed by us, based on image analysis of the echograms available from the B-scan system. Algorithms have been developed for evaluating the greylevels (or echo intensities or reflection amplitudes) of the pixels, normalizing them with respect to the reflection amplitude of the pericardium, and then printing out the grey-level distribution over an image. Appropriate software has been developed to designate scarred myocardial segments, based on the mean and standard deviation of the selected region on the echo image in comparison with these values for the pericardium.