3D acoustic resolution-based photoacoustic endoscopy with dynamic focusing

Bo Wang; Congcong Wang; Fangyi Zhong; Weiran Pang; Lili Guo; Kuan Peng; Jiaying Xiao

doi:10.21037/qims-20-625

3D acoustic resolution-based photoacoustic endoscopy with dynamic focusing

Quant Imaging Med Surg. 2021 Feb;11(2):685-696. doi: 10.21037/qims-20-625.

Authors

Bo Wang¹, Congcong Wang¹, Fangyi Zhong², Weiran Pang¹, Lili Guo³, Kuan Peng¹, Jiaying Xiao¹

Affiliations

¹ Department of Biomedical Engineering, Central South University, Changsha, China.
² Department of Biomedical Engineering, Guangzhou Huaxia Vocational College, Guangzhou, China.
³ Department of Biomedical Engineering, Hunan University, Changsha, China.

Abstract

Background: Acoustic resolution-based photoacoustic endoscopy (ARPAE) is a non-invasive potential tool for imaging gastrointestinal and urogenital tracts. However, current ARPAE systems usually only provide 2D sectorial B-mode images, and have the limitation of the image quality significantly deteriorating out-of-focus regions due to transducers with fixed focus in these systems. To overcome these limitations, we put forward a modified back-projection method that can provide 3D images with dynamic focusing in ARPAE.

Methods: A graphics processing unit (GPU)-based parallel computation technique was adopted for efficient computation. Both simulated and phantom/ex-vivo experiments were conducted to validate our method.

Results: The findings indicated that our proposed method can effectively improve the lateral resolution and signal-to-noise ratio (SNR) in the out-of-focus regions. For a target 3 mm from the transducer focus, the new method can improve 11 times in the lateral resolution, along with an improvement of up to 37 dB in the SNR.

Conclusions: 3D ARPAE provides high-quality imaging in both focus and out-of-focus regions.

Keywords: Photoacoustic endoscopy; dynamic focusing; lateral resolution; signal-to-noise ratio.