Confounding effects of myocardial background intensity and attenuation in contrast echocardiography:: An in vivo study

It has been shown in vitro that the time-intensity data of echo contrast agents may be influenced by the background intensity of the myocardium and attenuation at high contrast agent concentrations. In the present study, these effects are evaluated from in vivo data, An effect of background intensity of the myocardium on the determination of the transit rate of the contrast agent could not be demonstrated unambiguously, A statistically significant relation between transit rate and background intensity was found only for intermediate flows in the transmural region. The magnitude of this relation was such that it does not provide a serious source of error. Attenuation and shadowing typically underestimate the transit rate of the contrast agent, which results in overestimation of how, It is recommended that the lowest doses of contrast agent inducing myocardial opacification should be applied, (C) 1999 World Federation for Ultrasound in Medicine & Biology.