703-3 Second Harmonic Mode Imaging Improves Contrast Agent [SHU 508-A] Visualization in an In Vitro Model

Non invasive myocardial contrast echocardiography requires an ultrasoundimaging mode capable of detecting small amounts of a crossing lungs contrastagent (CA) which reach the cardiac muscle. At present, commercialB-Mode imaging can not visualize CA in myocardium after intravenous injectionand transpulmonary passage. Second harmonic Mode imaging (SHM) uses resonance properties of microbubbles to produce a gray scale imageof CA. We tested an prototype ultrasound machine (Acuson) using SHM to detect CA SHU 508-A (Schering AG, Berlin) flow in an in vitro model at variousconcentrations, For each CA injection, videointensity in arbitrary Units(VU), in SHM and B-Mode was assessed:SHU 508-Ainjected volume (ml)VUB-ModeVUSHMVU% increase0.1251932680.253151670.55369301.06987262.082102244.010011515SHM vs. B-Mode p < 0.0001ConclusionsSHM is more sensitive than B-mode in detecting SHU 508-A, particularly at lower CA concentrations. SHM has a potential for the evaluation of low CA concentration in clinical setting and therefore in myocardial perfusion studies after CA intravenous injection