How are images captured from modalities such as CT, MR, ultrasound, and nuclear medicine?
Images can be captured either by a video capture (frame grabber) board which connects directly to the composite video signal of either the image processor or the console, or digitally by connecting directly from a modality to a workstation over a network (such as, ethernet). The least expensive method to acquire digital data is through a DICOM file transfer. • How are plain film (standard radiograph) images captured? Standard radiographs can be digitized by either a video camera or a film scanner. Video cameras (commonly referred to as a “camera on a stick”) were in fact the method of digitizing any image for transmission as recently as five years ago. Typical camera systems utilize a light box designed to illuminate radiographs, an extension arm for holding the camera above the film, and a high-sensitivity video camera with a zoom lens. This is an inexpensive but poor-quality method of image acquisition. Film scanners and digitizers arrived on the teleradiology scene a few years ago.
