A portable digital imaging system for fluorescence-guided surgery is provided. The system includes a portable probe comprising a light source, a fluorescence detector, a digital signal output, a memory and a processor. The system also includes a computer in communication with the portable probe and a display. The portable probe excites a fluorescent label-containing tissue within a surgical field in response to the light source of the portable probe illuminating the fluorescent label-containing tissue. The computer displays a real-time image visualization of the surgical field on the display in response to the computer in communication with the display receiving and processing a digital signal from the digital signal output of the portable probe.