Fast photoacoustic imaging system based on multi-element linear transducer array CT-scanning

In this paper, a new photoacoustic imaging system based on multi-element linear transducer array CT-scanning was present. In this imaging system, the 532-nm laser light with the repetition rate of 10 Hz and the pulse width of 10 ns used as the excitation source. A 64-element linear transducer array with the central frequency of 7.5 MHz is used to capture photoacoustic signals by rotating the multi-element linear transducer array with a step of 18 degrees. The photoacoustic images are reconstructed by the modified limited-field filtered back projection algorithm, which is modified from the limited-field filtered back projection algorithm adapt to reconstruct the photoacoustic images with the photoacoustic signals collected by CT-scanning. The experiments of a phantom model and in vitro blood vessels were performed with this system. A clear image can be obtained within 1 minute. The experimental results demonstrate the reconstructed photoacoustic images with this system are greatly improved; the boundaries of the round absorbers and almost the vascular ramifications of the chick embryo chorioallantoic membrane are accurately resolved. This system may have potential in clinical application to fast image the protrudent organs of the human body, such as breast and head.