Synthetic aperture composite focusing for high framerate medical ultrasound imaging

Abdominal medical ultrasound suffers from a low frame rate due to the acquisition of several sub-images at individual transmission focal points. Here a synthetic aperture method with prefocused sub-apertures is analyzed which instead of stitching N
s
²
transmit zones together for composite focusing, uses N
s
prefocused sub-apertures to achieve close to dynamic focus. A frame rate increase of N
s
²
/2 is achieved. The proposed method is robust to motion artifacts and suitable for second harmonic imaging. Simulated RF-data from point targets and tissue-mimicking phantoms has been processed to evaluate the proposed method.