Effect of PSF on super-resolution ultrasound imaging implemented by bSOFI method

Ultrasound (US) imaging technique is one of the most common imaging techniques in clinical applications. However, the spatial resolution of ultrasound is limited. Recently, a fast super-resolution ultrasound imaging (SR-US) technique has been proposed to break the diffraction limit, which is implemented by using super-resolution optical fluctuation imaging (SOFI) method. Further, to reduce the nonlinear response to brightness and blinking heterogeneities in highorder SOFI image, a balanced SOFI (bSOFI) method can also be used in SR-US. It should note that when using bSOFI method, the point spread function (PSF) of the imaging system is a key factor that affect the obtained imaging performance of SR-US. However, bSOFI is a method from optical microscopy. The PSF of optical system is significantly different from PSF of US system. To better apply bSOFI method to ultrasound, in this paper, we investigate the effect of PSF on the imaging performance of SR-US. Especially, to speed up the data acquisition and further improve the temporal resolution of SR-US, here, the US data are acquired by plane wave (PW) scan. The results from the numerical simulation indicate that when considering the characteristic of PSF in ultrasound (i.e., sigma(x) not equal sigma(y)), by using bSOFI method, we can greatly improve the imaging performance of US, where the smaller line structure can be effectively resolved compared to the standard US imaging method. As a result, the technique (bSOFI method combined PW scan) provide the potential in ultrafast SR-US imaging.