Photoacoustic Imaging

Photoacoustic imaging has demonstrated promising results for in vivo biomedical imaging. The synergy of light and sound makes photoacoustic imaging unique among other optical imaging modalities. Photoacoustic imaging systems can be implemented in two types: photoacoustic computed tomography (PACT) and photoacoustic microscopy (PAM). For PACT, a laser beam illuminates a broad region, and an ultrasonic array transducer is employed for acoustic detection. The image is formed by image reconstruction. On the other hand, for PAM, either a focused acoustic transducer (for acoustic detection) or a focused laser beam (for illumination) is used to provide spatial resolution. The image is rendered by point-by-point scanning of the imaging head.

We investigate photoacoustic imaging in three aspects: miniature imaging probes, resolution enhancement algorithms, and biomedical and industrial applications. (i) We developed several miniature photoacoustic imaging probes including all-optical photoacoustic imaging probe, double gradient-index PAM imaging probe, and forward-view wide-field PAM imaging probe. These imaging probes have potential for endoscopic imaging applications. (ii) We proposed algorithms for resolution enhancement in photoacoustic imaging, including mirrored synthetic aperture focusing technique and three-dimensional deconvolution. (iii) We explored applications of photoacoustic imaging in various aspects such as cell photoacoustic imaging, photoacoustic imaging for intensive care medicine, and photoacoustic imaging of lithium batteries.