Investigation on Effects of Acoustic Heterogeneity in Thermoacoustic Imaging Based on Compressive Sensing: A Simulation Study

Thermoacoustic imaging (TAI) has many promising applications in biomedical imaging. Compressive sensing (CS) based TAI is able to greatly improve the time efficiency of potential realistic applications of this technique. However, the CS based TAI method, referred to as CS-TAI, is grounded on the assumption of uniform acoustic speed in the entire background, which is sometimes not the case in real applications. Acoustic heterogeneity may cause some errors in the reconstructed images. This work investigates the effect of acoustic heterogeneity for the CS-TAI modality by simulation work. It is found that bigger acoustic heterogeneities incur higher distortions in the reconstructed images. But the CS method still yields better imaging quality than the traditional back-projection algorithm when acoustic heterogeneity presents.