New polygraph was especially designed for selecting the arbitrary phases in a cardiac cycle at where the corresponding radiograms should be synchronously exposed.
Then, a unit was established in which such polygraph, power injector, Xray generator, and film changer cooperate each other. The radiography based on these 2 fundamental mechanisms is tentatively called phaseselective radiography (PSR) in this paper.
In the present study, the selection of the phases in this manner was carried out successively only at arbitrary 1 or 2 places (A or A and B) in a cardiac cycle because of mechanical limitations.
Furthermore, since these selected phases are accompanied by the delay circuits (0-8 pulse counts) respectively, 45 pairs of contrast radiograms can be theoretically demonstrable for each of clinical purposes.In addition, test recording prior to actual execution was sufficiently available to obtain accurate determination of the phase required.
Meanwhile, application of Sakura isodensity recorder was of usefulness in delineation of differences in density on Xray film and its salient feature was to show the same silhouette as original profile being different from the conventional curve presentation.