Fig. 2

The human–machine interaction is constrained by human and contextual factors. Typically, the display is around 60 cm from the radiologist. At this distance, the field of view is around 50 cm (around 21 in.). Considering the maximum angular resolution of the eye, the display can have maximum pitch of 0.21 mm. This corresponds to a 3-megapixel screen. The human retina contains two types of photoreceptors, rods and cones. The cones are densely packed in a central yellow spot called the “macula” and provide maximum visual acuity. Visual examination of small detail involves focusing light from that detail onto the macula. Peripheral vision and rods are responsible for night vision and motion detection