Ultrasound beamforming and image reconstruction using CPU and GPU

In digital beamforming for creating ultrasound images, the digitized echo signals received by transducer elements have to be delayed to make their wave fronts and phases equal before summing these signals for a desired focus. In general, the delay values are not always located at sampled points. In practical, the values of the delayed signals are estimated by the values of the nearest samples. This method is easy and fast, however, inaccurate. In order to increase the accuracy of the delayed signals and, consequently, the quality of the beamformed signals, other methods should be used. For example, the I/Q interpolation method, which is more time-consuming but provides more accurate values than the nearest sample method. The objective of this paper is to compare the signals after dynamic receive beamforming, in which the echo signals are delayed using two methods, the nearest sample method and the I/Q interpolation method. The visual qualities of the reconstructed images are compared, as well as the qualities of the beamformed signals and the computational speeds using CPU and GPU.