Enhancing Image Quality of Photoacoustic Tomography Using Sub-Pitch Array Translation Approach: Simulation and Experimental Validation

<italic>Objective</italic><italic>:</italic> 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 <italic>λ</italic> pitch linear array transducer at receive for photoacoustic tomography (PAT) application. <italic>Methods:</italic> 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 <italic>λ</italic>/2 and <italic>λ</italic>/4 pitch data were reconstructed and compared against conventional <italic>λ</italic> pitch reconstructed PAT image using simulation and tissue mimicking phantom experiments in terms of improvements in resolution and contrast. <italic>Results:</italic> 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 <italic>λ</italic>/2-pitch configuration when compared to the conventional <italic>λ</italic>-pitch configuration. <italic>Conclusion:</italic> It was demonstrated that <italic>λ</italic>/2- and <italic>λ</italic>/4-pitch configurations result in better LR and contrast than <italic>λ</italic>-pitch configuration. <italic>Significance:</italic> 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.