A multi-transducer approach for human carotid plaque imaging

A common approach in photoacoustic imaging (PAI) is to use a linear or curved piezoelectric transducer array, which provides flexibility and versatility during image acquisition. However, these PAI systems often have limited field-of-view (FOV), resolution, and contrast, resulting in low quality images. In this study, a multi-transducer approach is proposed to improve FOV, resolution, and contrast, with the goal of facilitating human carotid plaque imaging. A prototype consisting of multiple capacitive micromachined ultrasonic transducers (CMUTs) on a flexible array with shared channels was developed and evaluated using simulated and ex-vivo human carotid plaque samples. In numerical simulations, the results are evaluated based on input ground truth parameters. For ex-vivo plaque samples, results for multi-transducer are evaluated and compared to the images acquired with single transducer. All the results demonstrate that the proposed approach improves contrast, FOV, and most notably, it allows resolving the structural information in the medium where more than 25% improvement in gCNR values is achieved in both simulations and experiments compared to the PA images obtained with single transducer.