A high-speed laser perfusion imaging instrument including a laser source, a detector, a signal-processing unit, data memory, and a screen to display results. A section of a sample surface is illuminated with laser light reemitted light from the irradiated surface is collected by focusing optics on a 2D array of integrating photodetectors having elements that can be accessed individually or in a pre-defined selection of pixels at high speed. This 2D array measures intensity variations at each individual pixel. Average amplitude and mean frequency of the measured signal contain information about concentration and speed of moving blood cells. For real-time imaging, exposure time is used as a parameter to measure relative perfusion changes. These data are stored and processed with the signal-processing unit to deliver 2D flow maps of the illuminated sample section, and allow a simple overlay between a conventional image and processed flow maps.
