A Miniaturized Dual-Modality Photoacoustic Fusion Imaging System

A photoacoustic signal is proportional to a product of optical absorption coefficient and local light fluence; quantitative photoacoustic measurements of the optical absorption coefficients therefore require an accurate compensation of optical fluence variations. Usually, a supplementary diffuse optical tomography (DOT) is required to compensate the light fluence variations, but it is troubled by the bulky measurement system. In this paper, we propose a miniaturized dual-modality photoacoustic fusion imaging system. It utilizes an ultrasound sensor to receive photoacoustic signals for common photoacoustic imaging and extracts the passive ultrasound (PU) waves, backscattered laser-induced ultrasound waves, from the photoacoustic waves for diffuse reflectance (DR) imaging, simultaneously. Based on the dual-modality images of photoacoustic and DR, a further fusion photoacoustic imaging is implemented with the compensation the optical fluence variations. According to the experimental results, this miniaturized system can greatly reduce nearly 70% errors caused by the light fluence variations.