Abstract: A device, method, and system for detecting emboli in the brain is disclosed. A transcranial Doppler photoacoustic device transmits a first energy to a region of interest at an internal site of a subject to produce an image and blood flow velocities of a region of interest by outputting an optical excitation energy to said region of interest and heating said region, causing a transient thermoelastic expansion and produce a wideband ultrasonic emission. Detectors receive the wideband ultrasonic emission and then generate an image of said region of interest from said wideband ultrasonic emission. A Doppler ultrasound signal will also be deployed to image the region of interest. Doppler presents changes in velocity to map blood flow. Additionally, a dye can be given to visualize the brain vasculature and a perfusion measurement can be made in various regions of the brain along with the transcranial Doppler and the photoacoustic screening.