Quantitative estimation of ultrasonographic attenuation in the myocardium using conventional echocardiographic instrumentation.

Through the careful and judicious use of the time gain controls in conventional echocardiographic instrumentation, we have found that it is possible to obtain quantitative estimates of the attenuation of ultrasound beams even in vivo. These estimates are based on the quantitative comparison of the amplitude of the echo waveforms at different depths. Here, we report on such attenuation measurements using both a tissue phantom and the interventricular septum of the myocardium in vivo. The in vitro estimates of attenuation with this method are in agreement with independent laboratory measurements of the same parameter. In vivo measurements on the myocardium indicate oscillations in the magnitude of the attenuation over the heart cycle and suggest methods for the quantitative assessment of a variety of pathologic conditions in the myocardium noninvasively using conventional ultrasound scanners.