The present invention relates to medical devices such as endoscopes that may be used to visualize biological material during a medical procedure, such as surgery. In one embodiment, the present invention provides for an endoscope comprising one or more electronic-cameras arranged to create one or more stereo picture pairs to permit quantitative 3-dimensional (3D) imaging and analysis. In another embodiment, the present invention provides a method of imaging comprising using a 3D endoscope with one or more electronic cameras to create one or more stereo picture pairs.