Evaluation and Optimization of Real-Time Perfusion Imaging Using Multiple Ultrasound Systems With Imagify Microspheres

Abstract

Current commercially available ultrasound systems have proprietary contrast-specific imaging modes to evaluate myocardial contrast enhancement (MCE). Each of these modes uses a different pulsing scheme and has unique system terminology and a proprietary name. The aim of this study was to determine optimal system settings and MCE duration using Imagify (perflubutane polymer microspheres), a new ultrasound imaging agent undergoing development for perfusion stress echocardiography to detect coronary artery disease. Thirty-nine patients were enrolled. Four ultrasound systems with real-time, low mechanical index (nonlinear, multi-pulse) modes were evaluated. Optimal MCE settings were determined qualitatively in the apical views through systematic adjustment of multiple settings while maintaining a frame rate consistent with stress echocardiography to produce high-intensity (bright-hyperechoic), transmural myocardial enhancement. When using the clinical dose of Imagify during real-time imaging, the optimized settings for three ultrasound systems allowed prolonged, clinically useful MCE with a mean duration of 9.5 minutes.