Enhancing image quality of photoacoustic tomography using sub-pitch array translation approach: Simulation and experimental validation

Objective: The purpose of this paper is to present a more convenient and practical alternate way of increasing the lateral discrete array sampling while using a typical λ pitch linear array transducer at receive for photoacoustic tomography (PAT) application. Methods: We have employed a linear translation-based approach, in which the array transducer is translated by sub-pitch amount to create an augmented RF frame data having denser lateral spatial sampling. The denser λ/2 and λ/4 pitch data were reconstructed and compared against conventional λ pitch reconstructed PAT image using simulation and tissue mimicking phantom experiments in terms of improvements in resolution and contrast. Results: The results from experiments demonstrate a 34.48% improvement in lateral resolution (LR), measured in terms of full-width at half-maximum of the lateral profile of point spread function, and a maximum of 7-dB improvement in contrast is achieved while using a λ/2-pitch configuration when compared to the conventional λ-pitch configuration. Conclusion: It was demonstrated that λ/2-and λ/4-pitch configurations result in better LR and contrast than λ-pitch configuration. Significance: Based on the results obtained, the proposed method has the potential to serve as an easy-To-integrate and simple way of achieving better image quality without requiring to increase the system complexity with existing transducer array probe technology in regular clinical scanners.