Figure 3

Ultrasonic delay-and-sum images, using experimental data from an array with 161 element and 0.155 mm pitch, of (A) a scatterer free region and (B,C) a region with a scatterer. White and black arrows show the location of the scatterer. Normalisation was performed on (A,C) the highest intensity noise pixel and (B) highest intensity scatterer pixel. (D) Graph shows the pixel intensity distribution of each ultrasonic image. Additional (E) graph highlights the 15 dB shift observed between the pixel intensity distributions with and without a scatterer.