Detection and quantification of myocardial scars by contrast-enhanced 3D echocardiography

Myocardial infarct scars are usually imaged by delayed-enhanced cardiac magnetic resonance (DE-cMR). In this study, we tested the hypothesis that the detection and quantification of myocardial scars can be evaluated by 3D echocardiography (3D-echo).

Fifty patients with a healed myocardial infarction (>3 months) and 10 controls underwent 3D echo and DE-cMR within 2 weeks. 3D-echo images were acquired with different settings, with or without contrast. The highest contrast-to-noise ratio was obtained with second-harmonic imaging (1.6/3.2 MHz), at a mechanical index of 0.5, in the presence of contrast. Using this modality, we calculated the sensitivity and specificity of the 3D-echo detection of cMR scars on a segmental basis to be 78% and 99%, respectively. On a per-patient basis, they were 96% and 90%, respectively. Good correlation and limits of agreement were found between the assessment of scar mass by 3D echo and DE-cMR (r=0.93, P<0.001; bias, 1.4+/-3.6 g), and the concordance between both techniques for the assessment of scar transmurality was good. Intraobserver, interobserver, and day-to-day reproducibility was comparable between 3D echo and DE-cMR for both the detection and quantification of scars.

Contrast-enhanced 3D echo is a promising new tool for the detection and quantification of myocardial infarct scars.