955-59 Harmonic Contrast Echocardiography: A New Method for Detecting Myocardial Opacification After Intravenous Injection of Contrast

Abstract

Detection of myocardial opacification after intravenous injection of contrast is of great diagnostic value. To achieve this goal. we applied harmonic imaging to myocardial contrast echocardiography. Contrast agents emit strong harmonics at double the frequency of transmitted ultrasound, while the tissue does not. Thus, harmonic imaging improves the tissue-agent contrast. We used a prototype phased-array harmonic echocardiographic system with a sector probe that transmits ultrasound at 2.5 MHz and receives at 5 MHz (Toshiba Corp.). SHU-508 (Schering), a galactose-based contrast agent, was injected through femoral vein (0.13–0.24 ml/kg; 400 mg/ml) in 5 anesthetized open chest dogs. Images were recorded on videotapes and subsequently analyzed with a Quadra 840AV (Apple) based microcomputer system. Time-intensity plots were generated in the end-diastolic images by setting the region of interest to the anterior LV wall. In 3 dogs. shortly after the opacification in LV lumen, the intensity in the myocardium increased and gradually declined to the basal level as shown in the figure. No significant hemodynamic alterations were noted with these doses of SHU-508. Thus, successful myocardial opacification can be achieved during harmonic imaging after intravenous injection of contrast. Harmonic contrast echocardiography is a feasible, promising technique to detect myocardial perfusion.