Medical ultrasound image quality improvement using synthetic aperture focusing on display pixels

In this paper, we propose synthetic aperture focusing (SAF) on display pixels to provide much clearer medical images. This method directly focuses on each pixel to solve the problem of image quality degradation which is occurred by the two-dimension interpolation of digital scan conversion. The suggested method applies SAF that uses the fixed focusing points of transmitters as virtual sources to improve contrast and signal-to-noise ratio. It also uses multi-order sampling to calculate the envelope of pixels with minimum computational costs. To verify the proposed method, the data obtained from the carotid region by using the 7.5MHz linear array is used. Since the suggested method shows distinct speckles and boundaries, the images can be used to eliminate speckles, extract tissue characteristic, and track speckles. This method provides 134% higher contrast and 55% lower computational costs than conventional SAF.