  Various methods have been proposed to enhance image quality in ultrafast
ultrasound. Coherent compounding can improve image quality using multiple
steered diverging transmits when motion occurring between transmits is
corrected for. Harmonic imaging, a standard technique in conventional focused
echocardiography, has been adapted for ultrafast imaging, reducing clutter.
Coherence-based approaches have also been shown to increase contrast in
clinical settings by enhancing signals from coherent echoes and reducing
clutter. Herein, we introduce a simple, unified framework that combines
motion-correction, harmonic imaging, and angular-coherence, showing for the
first time that their benefits can be combined in real-time. Validation was
conducted through in vitro testing on a spinning disk model and in vivo on 4
volunteers. In vitro results confirmed the unified framework capability to
achieve high contrast in large-motion contexts up to 17 cm/s. In vivo testing
highlighted proficiency in generating images of high quality during low and
high tissue velocity phases of the cardiac cycle. Specifically, during
ventricular filling, the unified framework increased the gCNR from 0.47 to 0.87
when compared against coherent compounding.
