Serial Planeography (Serioscopy) and Serial Planigraphy

Abstract

Introduction MANY methods for securing an x-ray film of a designated body section have been published under various names (1, 2). Those most frequently encountered in the literature are: (1) planigraph (Andrews and Ziedses des Plantes); (2) stratigraph (Vallebona); (3) tomograph (Grossman, Chaoul, and Twining); (4) x-ray focusing machine (Kieffer), and (5) laminagraph (Kieffer and Moore). In all of these methods various motions are imparted to the tube, plate, or patient, so that the designated plane (thin body section) is in focus, and is sharply defined on the x-ray plate, the other planes being eliminated from the picture by blurring. In August, 1936, we introduced an original method which we termed planeography (3, 4, 5). By planeography we were able to accomplish the following: (1) Roentgenographic films (planeograms) of all the object-planes could be demonstrated. (2) The depth of the object-planes so demonstrated could be determined by reference to a specially constructed curve the “standard depth curve.” (3) Localization and mensuration were possible. (4) It was shown that the planeograms did not represent the object-planes themselves but were only enlarged similar films of such planes, showing varying degrees of enlargement and displacement. (a) By correcting the enlargement of the planeogram, the object-plane could be reconstructed. (b) By correcting the displacement and enlargement of the planeogram, the object itself could be reconstructed. The delineation of planeograms was accomplished by superimposing two or more standard roentgenograms. Successive planeograms were demonstrated by sliding the roentgenograms one upon the other. The term, “planeography,” was coined by us to differentiate this method from planigraphy, stratigraphy, etc. Regarding this term, Jean Kieffer in a personal communication to us wrote as follows: “I think your differentiation of names is a very good one. Although the basic mathematics are similar to planigraphy, the procedures and results are different.” In September, 1937, Paul Cottenot (6) presented a paper before the Fifth International Congress of Radiology, termed, “Thoracic Serioscopy.” The method “consists in taking … four stereoscopic roentgenograms of the thorax. The four films are examined while superimposed one over the other in the same negative viewing box. By causing them to slide synchronously one over the other, the different thoracic planes, superimposed from the front backward, are successively brought into evidence, and at the same time one reads on a dial, graduated in centimeters, the depth of each of the planes examined.” The basic principles employed in serioscopy by Dr. Cottenot are the same as those elaborated by us under the term “planeography.” Apparently Dr. Cottenot rediscovered planeography independently, terming the method “serioscopy.” Dr. Cottenot employs “two pairs of stereo-roentgenograms, … with the axes of shift of the tube perpendicular to one another.”