1985 Volume 41 Issue 1 Pages 69-80
This paper describes the techniques of digital tomosynthesis and dynamic function analysis as applications of the digital fluorography. A new video digital tomosynthesis system was configured of modified tomographic apparatus with TV system, a video disk recorder or a video tape recorder, a co-ordinates transmission unit, digital frame memories and a small computer. Tomosynthesis images were reconstructed by shifting the projection TV images corresponding to the depth of tomogram, and by overlapping and integrating them. As a result, tomosynthesis image could be processed within three seconds in circular tomography and one second in linear tomography. After computer processing for minimization of artifacts from other slices, the border of the tumor and the streaky shadow of pulmonary vessels and bronchi in the digital tomosynthesis image were more clear than conventional tomographic image using X-ray film. The new DF system with ten mega bytes frame memories and micro computer was trial manufactured. The micro computer was also used for various post processings, such as remasking, cardiac function analysis and blood flow analysis. Global and segmental cardiac functions were displayed by volume and differential curve, time interval difference image, stroke volume image, amplitude image and phase image. These parameters were shown to be useful in the quantitative analysis of cardiovascular physiology. Regional per cent blood volume image and peak time image were computed using the temporal changes of contrast media at each pixels. These parameters were applicable to quantitative circulatory studies of the cereblar and abdominal arteries.
