[Quantitative evaluation and color display of echo intensity by two-dimensional echocardiography].

To assess myocardial tissue changes by two-dimensional echocardiography, quantitative evaluation and color display of the echo intensity were attempted using computerized image processing. The materials consisted of 11 patients with old anteroseptal myocardial infarction one year or more after the onset (OMI), and 12 normal subjects. Two-dimensional echocardiograms in the parasternal long-axis view were obtained using a commercially-available phased-array sector scanner. Scanner receiver settings including sensitivity-time control were maintained constant in all subjects. Images were recorded on the U-matic tape using a video tape recorder, then stop-frame end-diastolic images were converted to digital images. To measure echo intensity, regions of interest (ROI) were placed in the interventricular septum (IVS), the left ventricular posterior wall (LVPW), the left ventricular cavity, and the pericardium. The mean value of the echo intensities was determined for each ROI. Then, the relative echo intensity of the IVS or LVPW was calculated using the mean value of the pericardium as the maximum echo intensity, and the mean value of the left ventricular cavity as the minimum echo intensity. In normal subjects, the relative echo intensity of the IVS was 0.40 +/- 0.05 (mean +/- SE) and that of the LVPW was 0.31 +/- 0.02. By contrast, in patients with OMI, there was a significant increase (p less than 0.001) in the relative echo intensity of the IVS (0.71 +/- 0.06). The relative echo intensity of the LVPW was less than normal, but the difference was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)