Super-resolution ultrawideband ultrasound imaging using focused frequency time reversal music

We propose a super-resolution image reconstruction method which uses focused frequency time reversal (FFTR) matrices to focus in frequency for ultrawideband (UWB) ultrasound signals, as well as time reversal MUltiple SIgnal Classification (MUSIC) algorithm to focus spatially on the target location. Our combined method, which we refer to as FFTR-MUSIC, is motivated by the pressing need to improve the resolution of diagnostic ultrasound systems. Compared with the TR matched filter (TRMF) and incoherent TR-MUSIC approaches, our proposed method has lower computational complexity, higher visibility, higher robustness against noise, and higher accuracy for imaging point targets when the targets are closely located. Our simulation results show that under mild speckle and noise conditions, the FFTR-MUSIC can resolve objects less than 200 μm.