School of Allied Health Sciences, Osaka University Faculty of Medicine, 1-7 Yamadaoka, Suita-shi, Osaka 565-0871, Japan
Acoustic shadow, Artifact, Contrast, Echocardiography, Video intensity
Background and purpose The high dose of contrast agent required for intravenous myocardial contrast echocardiography (MCE) also causes acoustic shadowing that interferes with myocardial opacification. We examined three methods of administering contrast agent to minimize this acoustic artifact. Methods We studied five closed-chest dogs. MCE with administration of 1.0 ml Optison (FS 69) was performed using a prototype echocardiograph (Toshiba) capable of intermittent harmonic imaging (2.5 MHz/5.0 MHz). Three modes of administration were used: bolus injection for 1 second, slow infusion for 30 seconds, and slow infusion for 60 seconds. Duration of acoustic shadowing and intensity and duration of myocardial opacification were measured. Results Duration of shadowing was significantly shorter with the 60-second infusion than with either of the other two methods, while duration of myocardial opacification after termination of shadowing was longest with the 60-second infusion. Conclusion The slow infusion method is useful for reducing the acoustic artifact without diminishing myocardial opacification.