[5 years quality assurance in accordance with the roentgen regulation. Benefits, costs, necessary innovations]. / 5 Jahre Qualitätssicherung nach der Röntgenverordnung. Nutzen, Kosten, notwendige Weiterentwicklungen.

Guidelines and standards supplementing the German "Röntgenverordnung" initiated a complex system of quality control in diagnostic radiology. Cost and profit are analysed for two hospitals of comparable size (Klinikum Buch and Klinikum Nürberg). The considerable expenses that must be incurred for measuring devices, equipment, working time and extra charges on the one hand, are the items that are opposed to achieving a higher image quality and dose reduction on the other. Public quality control enables to demonstrate the quality and to optimise imaging procedures in diagnostic radiology. A critical evaluation of the results of quality control suggests further developments. We should consider larger time intervals for quality tests in some cases, while focussing on techniques with high radiation exposure, e.g. computed tomography, where dose reductions are highly effective.

[Costs and performance in roentgen diagnosis--conventional technique versus digital technique]. / Kosten und Leistungen in der Röntgendiagnostik--konventionelle Technik versus digitale Technik.

Relationships from benefits-costs analyses in radiography are presented. The impact of several factors (equipment, frequency of examinations, ...) on the planning of a department and special financial aspects, e.g., leasing of equipment, are discussed. The cost relationships of conventional versus digital radiography are demonstrated for the example of a 1000-bed hospital.

[Experiences with a new film-screen system in pediatric thoracic radiography]. / Erfahrungen mit einem neuen Film-Folien-System in der pädiatrischen Thoraxdiagnostik.

PURPOSE: To compare the x-ray images made by the Kodak InSight Pediatric Imaging System (InSight P) with conventional film-screen systems in pediatric chest radiography. MATERIAL AND METHODS: The comparison involved chest radiographs made using Quanta-Fast-Detail/Cronex 4 (DuPont), Trimax 16/XDA (3 M) and DuPont UVR/UVL systems. The image quality of critical structures and the physical parameters of quantum interference, contrast and resolution were assessed. The energy path of the system was assessed by preparing density curves. Test conditions were in accordance with the latest guidelines of the Bundesärztekammer (German Physician's Association). RESULTS: The mediastinal area, retrocardiac and paravertebral spaces and the peripheral vessels of the lung were all displayed more distinctly using InSight P. The reason for this seems to be a lower degree of quantum interference associated with this system. With tube voltages between 60 and 80 kV, InSight P displayed a relatively low degree of sensitivity. CONCLUSION: InSight P can be used to produce predominantly high quality chest radiographs of infants between one and five years of age. However, this system has limited sensitivity in the tube voltage range recommended by the German Physicians' Association.

[The importance of optical density for x-ray film screening]. / Bedeutung der optischen Dichte für die Röntgenbildbetrachtungsbedingungen.

The requirements of DIN 6856, part 1 (draft), for x-ray film screening conditions can be substantiated qualitatively and partly also quantitatively, e.g. by means of the ROC concept. In addition, the tolerance range of the optical density is seen to increase with increasing light intensity of x-ray film observation conditions. The light intensity of x-ray film screening conditions should be limited to 2500 cd/m2 to 3000 cd/m2 as a maximum to avoid the enhanced radiation of the patient, with is increased by 50% or the distribution rate of the optical density should be checked from time to time.

[Quality control of film viewing boxes]. / Qualitätskontrollen an Filmbetrachtungskästen.

Film inspection boxes have been examined in order to find out whether the introduction of the Roentgen regulation has led to positive results with regard to amount, illuminating density and homogeneity. In comparison to former results which have been published, it seems that the illuminating density is still too low. On the average, we found a value of 1.700 cd/m2.

[The effect of technical parameters on diagnostic quality]. / Einfluss technischer Parameter auf die Diagnosequalität.

By means of ROC (receiver operating characteristic) concept the importance of film density, film view, and film view time is determined for radiographs of different organs and symptoms considering the quality of diagnosis. On example of MTF (modulation transfer function) an organ specific optimization of X-ray imaging systems is realized. A recommendation is given for the application of screen-film systems with regard to noise, image contrast, and X-ray tube voltage.

[Importance of blackening of films and conditions of assessment of films for diagnostic decision of X-rays of teeth, the tooth supporting apparatus and adjacent structures of the jaw]. / Die Bedeutung der Filmschwärzung und Filmbetrachtungsbedingungen für die diagnostische Entscheidungsleistung bei Röntgenaufnahmen der Zähne, des Zahnhalteapparates und der angrenzenden Kieferstrukturen.

The influence of blackening of films and conditions of assessment of films for diagnostic decisions had been examined. Various pictures of the Periodontitis apikalis chronica at x-ray pictures had been chosen the subject of examination. It should be ascertained by means of the ROS concept to what extent variations of the above-mentioned parameters will result in false diagnoses. The most favourable result is gained with film blackening of 1.2 SE and a lightness of the film equipment of 12,000 Lx. A reduced lightness of the equipment will reduce the quality of diagnostics in essential manner. Optimum conditions for evaluation of the film are given for pictures over- and under-exposed.

[Explanations for the standard in roentgen diagnosis: basic tests of the thoracic organs--adults]. / Erläuterungen zum Standard Röntgendiagnostik: Basisuntersuchung der Thoraxorgane--Erwachsene.

Explanations are given concerning the standard of radiodiagnostics--basis examination of the organs of the thorax/TGL-No. 36661, which shall facilitate the understanding of the parameters given. It results from the fact that the roentgenological examination of the organs of the thorax begins with a posterior-anterior ray-path radiograph of the thorax. In these cases the large format technique with film-foil-combination and the fluorography are classified as equivalent. With regard to the high speed of movement to be expected is striven for the achievement of possibly short times of exposure. The authors briefly enter the particularities of the radiograph of the thorax in lateral as well as in the full size radiograph sitting and lying positions and at the patients bed. Due to the law solution and the higher radiation dose the fluoroscopy is to be used only with regard to the findings and other information concerning the patient.

[The influence of different parameters for roentgenologic recognition of disseminated lung diseases (author's transl)]. / Zum Einfluss einiger Parameter auf die röntgenologische Erkennbarkeit disseminierter Lungenerkrankungen.

The influence and diagnostic value of different film blackness, of different consideration times and of different layer angles for the diagnostic quality in disseminated lung diseases was examined by using the ROC-conception. The results of these examinations show, that variation of film blackness by +/- 25% have no influence of the diagnostic quality. Longer consideration times have a higher diagnostic accuracy than short consideration times. Moreover we found, that radiography, produced with lower layer angles, for example the zonography, allow a higher diagnostic accuracy than tomograms, which were produced with a great layer angle.