HDN:Hybrid Deep-learning and Non-line-of-sight Reconstruction Framework for Photoacoustic Brain Imaging

Photoacoustic imaging (PAI) combines the high contrast of optical imaging with the deep penetration depth of ultrasonic imaging, showing great potential in cerebrovascular disease detection. However, the ultrasonic wave suffers strong attenuation and multi-scattering when it passes through the skull tissue, resulting in the distortion of the collected photoacoustic (PA) signal. In this paper, inspired by the principles of deep learning and non-line-of-sight (NLOS) imaging, we propose an image reconstruction framework named HDN (Hybrid Deep-learning and Non-line-of-sight), which consists of the signal extraction part and difference utilization part. The signal extraction part is used to correct the distorted signal and reconstruct an initial image. The difference utilization part is used to make further use of the signal difference between the distorted signal and corrected signal, reconstructing the residual image between the initial image and the target image. The test results on a PA digital brain simulation dataset show that compared with the traditional delay-and-sum (DAS) method and deep-learning-based method, HDN achieved superior performance in both signal correction and image reconstruction. Specifically for the SSIM index, the HDN reached 0.606 in imaging results, compared to 0.154 for the DAS method and 0.307 for the deep-learning-based method.