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 ag ents may be influenced by the background intensity of the myocardium and at tenuation at high contrast agent concentrations. In the present study, thes e effects are evaluated from in vivo data, An effect of background intensit y of the myocardium on the determination of the transit rate of the contras t agent could not be demonstrated unambiguously, A statistically significan t relation between transit rate and background intensity was found only for intermediate flows in the transmural region. The magnitude of this relatio n was such that it does not provide a serious source of error. Attenuation and shadowing typically underestimate the transit rate of the contrast agen t, which results in overestimation of how, It is recommended that the lowes t doses of contrast agent inducing myocardial opacification should be appli ed, (C) 1999 World Federation for Ultrasound in Medicine & Biology.