Abstract 1067: Detection and Quantification of Myocardial Scar Using Contrast-Enhanced 3D-Echocardiography
Background. On conventional 2D-echo images, scar tissue usually appears brighter than normal myocardium. In this study, we tested the hypothesis that the presence and extent of myocardial scar can be evaluated using 3D-echo.
Methods. To test this, we studied 50 patients with a prior myocardial infarction (> 3 months) and 10 controls, who underwent 3D-echo and delayed-enhancement cardiac magnetic resonance (DE-cMR) within 2 weeks. 3D-echo images were acquired at mechanical indexes from 0.1 to 0.7, using or not tissue suppression (power modulation vs 2nd harmonic), as well as in the presence or absence of contrast agent. In each dataset, regions of interest were placed onto normal myocardium, scar tissue and LV cavity, to measure videointensity and contrast to noise ratios (CNR). On 3D-echo and DE-cMR datasets, the mass of scar tissue was measured using the Qlab and Segment softwares, respectively. Ten pts also underwent 3D-echo and DE-cMR twice on 2 consecutive days to evaluate the reproducibility of the techniques.
Results. The best CNR values were obtained using 2nd harmonic imaging, at intermediate MI, in the presence of contrast. Typical examples of 3D-echo and DE-cMR images are shown in the figure⇓. Good correlation and limits of agreement were found between the assessment of scar mass by 3D-echo and DE-cMR (r=0.92, p<0.001, bias: 0.5±2.9g, respectively). Interobserver reproducibility of scar mass measurement was good for 3D-echo and DE-cMR (ICC=0.92 and 0.93 respectively). Day-to-day reproducibility was similar among the 2 modalities (ICC=0.96 and 0.94 respectively).
Conclusion. 3D-contrast echo is a promising tool for assessing the presence and extent of myocardial scar.