International Review of Educational Cinematography (Jan-Dec 1934)

THE CINEMA IN SCIENTIFIC RESEARCH 81 shorter poses than those that would be necessary otherwise, using the same intensity of Rontgen rays, with excellent results. It was thus possible to reduce considerably the time required to make a good radiogram, even with a not excessive intensity, without fear of ruining irreparably the gas ampules used at that time, even though the operation should be continued for some seconds. Already in 1909 Grodel, making use of radiographic films placed between two reinforcement screens instead of photographic glass plates, was able to obtain, at 6070 cm. radiograms of the thorax and abdomen of from one-fifth to one-twentieth of a second. By means of this improvement and of a special mechanism for changing the plates, Grodel made some experiments in X-ray Cinematography, and projected a film of the movements of the heart, which he obtained by a series of 6 radiograms per second, before the Congress of Internal Medicine which was held in that year at Berlin. I must mention here that Grodel's clever idea of making use of the film instead of radiographic plates, and two reinforcement screens instead of one was later improved upon by the late lamented engineer Luboshez, who invented the double emulsion film, to be used between two reinforcement screens, a sensible system which is still in use today. Returning to X-Ray Cinematography, even Grodel's process was only an experiment, and although it came a step nearer to perfection, it was still very far from that goal and was not in any case a practical method. The number of radiograms obtained in a second was still much too small for reproducing in projections the actual movement exactly as it takes place, however reduced the radiograms might be, and even on condition of repeating the same series several times. It seems, however, that Grodel has recently succeeded, according to what we read, in taking 16 direct radiographs of the heart in one second, by means of a special very rapid transport of the film (a ribbon reel moving between two reinforcement screens). In 1909, Kastle and Rosenthal made known a method they had worked out, which allowed of the direct taking of many instantaneous radiograms of an organ in movement, one after another, for the entire duration of its kinetic activity. They called this the kiorontgenography, instead of Rontgen Cinematography, since, like the preceding methods it did not reach the intent of reproducing the actual movement in the projection, while it was, on the other hand, sufficient to give a fairly exact sensation of the complex life animating the moving organ during radiography. By means of this system, the authors could give an idea, not only of the principal phases of the movements of an articulation, which can be made to move slowly, and of the gastro-duodenal system, where the peristaltic waves are sufficiently slow, employing from 10 to 12 seconds in their course from the cardia to the pylorus, but also of the heart and respiration. Their biorontgenograph was constructed for radiographic plates, 18 by 24 cm. in size, and for a series of 13 radiograms and the total duration of 20-22 seconds (on 30-60 mA and 220 volts). The 1 3 radiographic frames containing one film each were collected in a vertical pack in a special support, against one side of which the patient was placed during the radiography. The first film having been sensitized, the frame that enclosed it was automatically dropped, by a special mechanism, into a collecting receptacle, and its place was automatically taken by a second film, and so on. The right moment for lighting the Rontgen ampules and changing the film was regulated by electrical devices. It is to this instrument of Kaestle and Rosenthal's that we owe particularly the more complete analysis of gastric peristalsis ; and it is the instrument which enables us, by means of outline drawings traced over the images of single radiograms, to superpose the single pictures obtained, and then to make a synthetic total of all the movements of the stomach. But, while it attained the object aimed at for purposes of study, it marked scarcely any real progress in the field of