Synthetic aperture imaging in medical ultrasound with correction for motion artifacts

The authors state that a synthetic receive aperture (SRA) system of a relatively simple design could increase the resolution of a phased-array imaging system several-fold, by utilizing a given number of parallel receive channels to address a larger number of transducer elements through multiplexers. A 1×N phased array can be extended linearly to improve lateral resolution, or it can be split into an M×N array in order to improve resolution in the elevation dimension. Images from an SRA system are degraded by any tissue/transducer motion during data acquisition. This degradation can be corrected by estimating the axial component of the motion and then realigning the data. A cross-correlation technique, which detects the phase difference between two similar lines of RF data (one for each receive subaperture), is used to perform this correction. The results of a theoretical analysis, of simulations, and of laboratory experiments are presented to demonstrate the advantages of using SRA compared to using conventional phased-array imaging