Image Separation Radioisotope Scanning

Discrimination of an image from its background in radioisotope scanning depends on many factors. Photoscanning (1, 2) is a useful means of increasing contrast. Discrimination also depends on how well the image contours may be separated from others in the background, and improvement should be possible, in some instances, by separation of images of radioactivity according to their depths in the body. We have sought to accomplish this by exploring the application of principles of stereoradiography and body-section radiography to radioisotope scanning. Rectilinear Scanning The rectilinear scanning pattern is most commonly employed; that is, an area of the body is scanned in a sequence of straight parallel strips (Fig. 1). With rectilinear scanning, images from all levels in the body are superimposed on the recording. As a consequence of this overlapping, the contours of a tumor image may be lost in a confusion of patterns resulting from overlying or underlying radioactivity. The characteristics of ordinary re...