Bush__The_Essential_Physics_for_Medical_Imaging - Biomedical ...

For example, it is often useful to superimpose nuclear medicine images, which displayphysiology, but may lack anatomic landmarks, on CT or MRI images. In thiscase, the nuclear medicine image is usually superimposed in color on a gray-scaleMRI or CT image.Hard-CoPY DevicesDigital images may be recorded on photographic film using either a video imageror a laser imager. Most video imagers use the analog video signal produced by thevideo interface. A video imager consists of a video monitor; a film holder; and oneor more lenses, each with a shutter, to focus the video image onto the film, allencased in a light-tight enclosure. A laser imager scans a moving film with a laserbeam to produce the image, one row at a time. Most video and laser imagers allowthe user to record several images on a single sheet of film. Video and laser imagersare discussed in more detail in Chapter 17.