M-mode photoacoustic flow imaging

Recently, there has been a growing interest in the development of photoacoustic flow measuring methods aimed to study microvascular blood flow in deep tissue. Here, we describe a method of M-mode photoacoustic flow imaging, where a photoacoustic microscope equipped with a high repetition rate pulsed dye laser is used. As a demonstration, we studied the flow of a diluted suspension of carbon glassy particles in a small tube, and extracted the flow profile. Potentially, the method can be applied to detect the blood flow in microvessels either directly or by injecting optically absorbing particles.