ROENTGENOGRAM [rentgeno-(by name V. Rentgena ) Greek gramma of the devil, the image] — the image of an object received by impact on it by x-ray emission and recorded on material, sensitive to this radiation, as a rule on a film.
The river is the objective document X-ray analysis (see).
The river received by photographing of the x-ray image from the fluorescent screen or the screen of the electron-optical converter call flyuorogrammy (see. Fluorography ).
The x-ray emission which passed through the studied object creates the hidden image of this object in a light-sensitive emulsion of a x-ray film. After photo processing of a film (manifestation, fixation, washing and drying) on it the resistant negative image consisting of light and dark sites according to attenuation range of radiation in sites of an object, different in the size, density and chemical structure is formed (see. X-ray inspection , Skialogiya , X-ray photographic materials ).
The main criteria of quality of R. defining its suitability for the purposes of radiodiagnosis are contrast, sharpness and lack of artifacts.
Contrast represents a difference in optical density between the neighboring sites of the x-ray shadow image. It depends on the wavelength (rigidity) of x-ray emission, photographic characteristics of a film, type of X-ray intensifying screens (see. X-ray analysis ), mode of photographic processing of a film, etc. Quality of the image on R. with excessively high or lowered contrast can be improved by method logegrafiya (see).
Sharpness is defined by the clearness of contours of shadow elements on the River. Insufficient sharpness can be connected with the movements of an object during shooting (dynamic unsharpness), and also with big sizes of focus of a X-ray tube or with incorrectly chosen ratio of distances focus — an object — a film (geometrical unsharpness). Dynamic unsharpness is usually reduced, reducing dwell time and fixing a dischargeable part of a body. For elimination of geometrical unsharpness increase distance focus — a film, reduce distance a film — an object. Sharpness can be increased also by use of fine-grained films and X-ray intensifying screens.
R.'s artifacts call any shadows on R. which are not connected with the studied object (see. Artefact ). Artifacts complicate R.'s analysis as can mistakenly be accepted to foreign bodys, concrements, the centers of an inflammation (e.g., in lungs), sites of destruction of fabric (e.g., in bones), etc. Defects of X-ray intensifying screens, films at violation of the rules of their storage or the treatment of them, errors of photo processing of a film happen origins of artifacts most often.
Each R. shall be properly issued. By means of a light or roentgenogram marker on it put down the party (right, left) the studied object, number of a research, time of production of a picture (e.g., time after administration of contrast medium at excretory urography). By the same way or by hand on R. do a text with the indication of a surname and age of the patient, date of a research and establishment, in Krom it was made.
Rubles study on the special device — the negatoscope allowing to consider R. in the transmitted light scattered by means of ground glass. Rubles place on the negatoscope so that the image corresponded to the picture seen on the screen during roentgenoscopy i.e. as if the patient costs, turned to the doctor by the person or the corresponding side.
Bibliography: X-ray engineering, under the editorship of V. V. Klyuev, book 2, page 235, M., 1980; Technical means of radiodiagnosis, under the editorship of I. A. Pereslegin, M., 1981; Lehrbuch der Rontgendiagnostik, hrsg. v. H. Schinz u. a., Bd 1, S. 25, Stuttgart; 1965.
V. V. Kitayev.