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Background: The acute abdomen is a life-threatening condition that demands urgent intervention. The required diagnostics should address the core problem and has to be chosen based upon the diagnostic strength of each diagnostic tool. Modalities with limited discriminating information regarding differential diagnosis have to be avoided. Expectancy and thoughts of the radiologist often differ from the view of the clinician in the emergency department., Objective: The decision about which diagnostic tools are valuable or unnecessary in the emergency setting is made from a surgeon's point of view. Close communication with radiologists is mandatory. We demonstrate the importance of clinical signs and symptoms and their correlation with helpful radiologic diagnostics., Conclusion: The emergency radiologic diagnostic workup of acute abdomen has to be targeted and the radiologist must answer the questions in order to clarify whether an operation is indicated and to help define the surgical strategy. In emergency surgery as in acute abdomen extended diagnostics to reach a decision is a dangerous waste of time and must be avoided at all costs. Therefore close communication with the radiologist is crucial.

Purpose:  Recent developments in medical technology have broadened the spectrum of X-ray procedures and changed exposure practice in X-ray facilities. For this reason, diagnostic reference levels (DRLs) for diagnostic and interventional X-ray procedures were updated in 2016 and 2018, respectively. It is the aim of this paper to present the procedure for the update of the DRLs and to give advice on their practical application., Materials and Methods:  For the determination of DRLs, data from different independent sources that collect dose-relevant data from different facilities in Germany were considered. Seven different weight intervals were specified for classifying pediatric X-ray procedures. For each X-ray procedure considered, the 25th, 50th, and 75th percentile of the respective national distribution of the dose-relevant parameters were determined. Additionally, effective doses that correspond to the DRLs were estimated., Results:  In procedures with already existing DRLs before 2016, the values were lowered by circa 20 % on average. Numerous DRLs were established for the first time (9 for interventional procedures, 10 for CT examinations)., Conclusion:  For dose optimizations even below the new national DRLs, the BfS recommends establishing local reference levels, using dose management software (particularly in CT and interventional radiology), adapting dose-relevant parameters of X-ray protocols to the individual patient size, and establishing internal radiation protection teams responsible for optimizing X-ray procedures in clinical practice. When applying good medical practice and using modern equipment, the median dose values of the nationwide dose distributions can not only be easily achieved but can even be undercut., Key Points: · German diagnostic reference levels (DRLs) für diagnostic and interventional X-ray procedures were updated in 2016 and 2018, respectively.. · For X-ray procedures for which DRLs existed already before the update, the updated DLRs were lowered by circa 20 %, on average.. · For CT and interventional radiology, new DRLs were established.. · X-ray procedures have to be optimized even below the DRLs.., Citation Format: · Schegerer A, Loose R, Heuser LJ et al. Diagnostic Reference Levels for Diagnostic and Interventional X-Ray Procedures in Germany: Update and Handling. Fortschr Röntgenstr 2019; 191: 739 - 751., Competing Interests: Disclosure The authors report no conflicts of interest in this work., (© Georg Thieme Verlag KG Stuttgart · New York.)

Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Objective: The aim of this study was to develop a new radiographic and measurement technique for use in the canine elbow (putting axial load on the joint during radiography and obtaining objective quantification of the resulting joint conformation), assess its reliability in relation to positioning artifacts and repeat measurements as well as to establish reference values. A radiographic technique for quantifying the radioulnar congruence or incongruence under load in vivo was to be developed., Material and Methods: In 27 dogs free of lameness, radiographs of 47 elbow joints with or without load (medio-lateral, cranio-caudal; anaesthetised dog in lateral recumbency), as well as radiographs with the animal standing (cranio-caudal) were examined. Digital measurements of the subchondral jointspace-width, subchondral bone-width and an angle were taken., Results: Reproducible length and angle measurements of anatomical landmarks in the elbow joint were obtained. By normalizing the length measurements parameters it was possible to compare radiographs taken from three different views in an animal as well as from different animals. Measurements from radiographs taken in a standing position correlated with those taken with or without load, but displayed poor reliability. The values of the measured parameters in radiographs with or without load showed a small range of dispersion, thus enabling the establishment of reference values. The examined reliabilities were significant for several parameters., Conclusion: Taking radiographs in the standing dog is not practical and cannot be used as a standard procedure for our measurement technique. However, using radiographs with or without load in lateral recumbency it is possible to accurately describe the canine elbow joint and compile a set of reference values in the narcotised animal. It may be possible to objectively describe unphysiologic incongruency and to adequately discriminate it from physiologic conditions.

Quality management (QM) cannot be successfully implemented and performed without audits. The PDCA (Plan-Do-Check-Act) cycle is the core component of QM systems. In this cycle an audit represents the crucial step "check". Audits verify whether the performed actions and their results conform to the requirements. It is especially important to verify whether the principles of QM are omnipresent and fully implemented in a department or institution. The announcement of an audit may cause mixed feelings or even anxiety among the personnel to be audited. Without previous information and training the audit may be perceived as an act of control and intrusion into departmental affairs. The colleagues often fear sanctions if lapses are found or consider the audit to be a cross-examination. However, an audit is rather meant to be a helpful aid and a chance to continuously improve the departmental QM system by means of a constructive communication among colleagues. In the year 2009 the European Commission published guidelines for the performance of clinical audits in medical radiology, including diagnostic radiology, nuclear medicine and radiation therapy (Council Directive 97 / 43 / EURATOM). The aim is an optimal protection of the individual from the hazards of ionizing radiation and the directive expects radiological departments to perform clinical audits in accordance with national procedures.

Objective: A conventional high-resolution screen-film system (Film Kodak MIN-R S, Kodak MIN-R 2000) was compared with an indirect digital detector system (Varian PaxScan 4030E) for use in radiography of lizards., Material and Methods: A total of 20 bearded dragons (Pogona vitticeps ) with body masses between 123 g and 487 g were investigated by using conventional and digital image acquisition techniques. The digital image was taken with the same dose as well as half the dose of the conventional radiograph. The study was conducted semi-blinded as the x-ray images were encoded and randomised. Five veterinarians with clinical experience in reptile medicine served as observers. Exactly defined structures in three anatomical regions were assessed using a three-step scale. Furthermore, the overall quality of the respective region was evaluated using a five-step scale. Evaluation of the data was done by visual grading analysis., Results: None of the structures examined was assessed to be of significantly inferior quality on the digital images in comparison to the conventional radiographs. The majority of the results demonstrated an equal quality of both systems. For assessment of the lung tissue and the pulmonary vessels as well as the overall assessment of the lung, the digital radiographs with full dose were rated to be significantly superior in comparison to the film-screen system. Furthermore, the joint contours of the shoulder and cubital joints and the overall assessments of the humerus and the caudal coelomic cavity were rated significantly better on digital images with full dose compared to those with reduced dose., Conclusions: The digital flat panel detector technique examined in this study is equal or superior to the conventional high-resolution screen-film system used. Nevertheless, the practicability of a dose reduction is limited in bearded dragons., Clinical Relevance: Digital imaging systems are progressively being used in veterinary practice. The results of the study demonstrate the useful application of the digital detector systems in lizards.

The diagnostic reference levels (DRLs) for diagnostic and interventional X-ray procedures established in 2003 were updated in July 2010 by the German Federal Office for Radiation Protection on the basis of mean patient doses in X-ray facilities surveyed by the so-called competent medical expert offices. The new DRLs are immediately in force and in most cases markedly below the respective old levels. Moreover DRLs for pediatric CT examinations have been newly introduced. This article briefly summarizes the concept of DRLs and the essential changes.

Not all digital radiography systems allow an unrestricted image postprocessing for the radiologist. Depending on the X-ray system there are restrictions in varying brightness and contrast of the image. We compared grey level information that are given to the radiologist by various digital radiography systems. Histograms of differently postprocessed X-ray images were calculated, which were acquired by three different X-ray systems. We found that every modality has its own way of saving and converting the images into DICOM data. The processed image is either sent into PACS with the initial grey level range (10 or 12 bit) or the image is sent with a reduced grey level range due to windowing. The grey level range is associated with the ability of unrestricted windowing in PACS. So, taking an image with a reduced grey level range, the radiologist will face limited potential to optimise the window setting individually afterwards. The loss of image quality due to image transfer from the modality to PACS can lead to an information loss in the diagnostic relevant range.

In this study the quality of digital and analog radiography in dogs was compared. For this purpose, three conventional radiographs (varying in exposure) and three digital radiographs (varying in MUSI-contrast [MUSI = MUlti Scale Image Contrast], the main post-processing parameter) of six different body regions of the dog were evaluated (thorax, abdomen, skull, femur, hip joints, elbow). The quality of the radiographs was evaluated by eight veterinary specialists familiar with radiographic images using a questionnaire based on details of each body region significant in obtaining a radiographic diagnosis. In the first part of the study the overall quality of the radiographs was evaluated. Within one region, 89.5% (43/48) chose a digital radiograph as the best image. Divided into analog and digital groups, the digital image with the highest MUSI-contrast was most often considered the best, while the analog image considered the best varied between the one with the medium and the one with the longest exposure time. In the second part of the study, each image was rated for the visibility of specific, diagnostically important details. After summarisation of the scores for each criterion, divided into analog and digital imaging, the digital images were rated considerably superior to conventional images. The results of image comparison revealed that digital radiographs showed better image detail than radiographs taken with the analog technique in all six areas of the body.

The knowledge of the radiation exposure of the staff involved in X-ray examinations is one precondition for an optimisation of radiation protection. Hence the radiation exposure of the staff during X-ray examinations of dogs and cats was investigated in the Clinic for Small Animals. The study includes at least ten measurements for each of thirteen X-ray examinations of a dog and four of a cat. The equivalent doses of eye lens, thyroid, chest, hands, gonads, and lower leg were measured using TLD (LiF:Mg,Cu,P). The maximum values of 44.3 and 48.3 microSv were measured on the eye lens and the thyroid, respectively. The median and mean values of the equivalent doses on the seven measuring positions with the exception of eye lens (6.0 microSv) are lower than 5 microSv per radiograph. More than 95% of the equivalent doses on chest, hands, gonads, and lower leg are smaller than 2 microSv. Particularly eye lenses and thyroid are exposed to measurable doses. Altogether the radiation exposure of the staff is relatively low. Hence a manual fixation of animals is justifiable if the fundamental rules of radiation protection are observed.

Purpose: A possible complication in regard to osteosynthetic treatment of a lower radius fracture with a locking plate is perforation of the articular surface by screws or a malpositioned ulnar fragment. In order to create good conditions for a homogeneous, reproducible X-ray picture for post-operative imaging control, an appliance for the production of standardised X-ray views has been devised., Materials and Methods: The X-ray device was constructed at an angle of 20 degrees to the camera. The arm was positioned on the appliance in the side beam path, in shoulder adduction as well as in the dp-beam in 90 degrees abduction of the shoulder., Results: Through standardisation of the X-ray technique the appliance it is able to supply comparable and reproducible X-ray images. In practice, the representation of both the joint gap and the bolt in the resulting image could be improved., Conclusions: Better and comparable picture series can be created by standardisation of the imaging technique using this X-ray device.

In Germany pet owners are present during X-ray examinations of dogs and cats. Due to a change in the German X-ray Ordinance and the directive "Radiation Protection in Veterinary Medicine" it is necessary to determine the body dose of the pet owners. This study in the Clinic for Small Animals includes at least ten measurements for each of thirteen X-ray examinations of a dog and four of a cat. The equivalent doses of eye lens, thyroid, chest, hands, gonads, and lower leg were measured using TLD (LiF:Mg,Cu,P). The maximum value of 52 microSv was measured on the right hand. The 99 % -quantiles amount to 13 microSv for eye lens, 9 microSv for thyroid, 2.3 microSv for chest (under lead apron), 14 microSv for both hands, 2.1 microSv for gonads (under lead apron), and 2.0 microSv for lower leg. In every case the median and mean values at the seven measuring positions are lower than 2.5 microSv per radiograph. In view of the constant measured equivalent doses under the lead apron of less than 5 microSv for the trunk and gonads per X-ray examination the measurement of the personal dose of the pet owner during every X-ray examination of small animals is not justified. Alternatively, with reference to up-to-date measurements and the presented paper a certificate of exemption from the dose determination for pet owners could be applied for from the local authority.

Two important guidelines for the application of X-rays in medicine became effective on 1 October 2003 and 1 December 2003. These are testing guidelines for experts and quality assurance guidelines. Both guidelines are very extensive and not always easy to interpret. In the present paper the authors try to explain in detail some chapters important for radiology and to make the necessary technical background transparent. Both authors took an essential part in forming the guidelines.

To ensure safe, quick, pain-relieving, standardized, and reproducible high quality plain film radiography in fractures of the proximal humerus, the MSR splint was introduced into clinical practice. With the rectangular and completely radiolucent splint the shoulder radiographs are obtained in supine position by a sole radiographer. Two radiographs are taken in projection at 90 degrees to one another: the true anteroposterior and axillary views, the most important views for fracture visualization and assessment. The smooth flat bottom part of the splint glides easily across the X-ray table below the injured shoulder. The arm lying on the chest is carefully rotated externally up to the neutral position and placed in the splint, then fixed with Velcro fastening with the forearm supinated. The splint is adjusted to the patient for the anteroposterior view which is taken with the central ray directed at the coracoid process and perpendicularly on the film cassette. For the axillary view the MSR splint holding the upper extremity is carefully swiveled into a 80-90 degrees abduction position. Even in cases of comminuted fractures this maneuver is not painful for the patients. The X-ray tube is put into a horizontal position with the central ray pointing to the humeral head in an angle about 25 degrees to the long body axis. The cassette is placed upright in touch with the shoulder girdle. In our institution the MSR splint is not only routinely used for diagnosing fractures of the proximal humerus but also for radiological follow-up controls.

The ILO (1980) Classification has been revised during recent years. The new version is now available as the International Classification of Radiographs of Pneumoconioses (Revised edition 2000). The Guidelines booklet is currently available only in English. Those involved felt it was important to maintain continuity with the ILO (1980) edition, in particular to retain the standard radiographs, despite their restricted quality, so as to ensure comparability with earlier national and international data sets. The standard films illustrating pleural abnormalities, and 'u'-shadows, have been modified and reconstituted. The most important changes relate to assessment of film quality, pleural abnormalities, and additional symbols. In Germany, film quality is characterised as "+", "+-", "+--" and "u" according to whether the ability to assess pneumoconiosis is judged to be unimpeachable ("+") to unusable ("u"). If a film is not classified as "+", then written comments regarding defects are required. For "diffuse" pleural thickening, the ILO (2000) edition now requires the presence also of obliteration of the costophrenic angle. This was not required in the earlier (1980) edition and, as previously, is also not stipulated in the German version. A minimum width of 3 mm (previously 0-5 mm), coded "a", is required both for plaques as well as for the margin to the lateral chest wall. Congruence is thus achieved for criteria, which, in German practice, lead to an indication of suspect occupational disease. Plaques on the diaphragm are not considered for measurement of extent; they are only coded as present or absent. If calcification is identified, then this must also be classified and measured as a localised plaque. Extent of calcification on its own, previously coded "0" to "3", is no longer specified. The following new symbols, illustrated by new diagrams, have been introduced: aa = atherosclerotic aorta; at = apical thickening; cg = calcified granuloma (or other non-pneumocononiotic nodules); me = mesothelioma (already previously differentiated from "ca" on the German record sheet); pa = plate atelectasis; pb= parenchymal bands; ra = rounded atelectasis; od = other disease. (Examples of the latter are illustrated diagrammatically by lobar pneumonia, aspergilloma, goiter and hiatal hernia.) Earlier national differences (ILO 1980/German Federal Republic) on particular issues have also been agreed among German "double-readers" ["Zweitbeurteiler"]. However, conformity between the original (ILO 2000) text and the national (German) modified text has been retained in large measure. The detailed descriptions of the standard films differ in certain respects from the German (1980) definitions. Some revision of individual descriptions of the films are proposed. Except for a few differences, agreement was reached here too. The definitive date for the change in Germany is expected to be in early 2004. The standard films are already available now through ILO offices in Geneva or Bonn (addresses in appendix.)

Purpose: In the state of North Rhine-Westphalia (NRW), Germany, a survey was conducted on radiologic examinations ordered by general practitioners (GPs). Part II of this study aims to determine the quality of the process and outcome. The reference standard is the assessment of both radiologists and physicians without board certification in radiology working at a university hospital and in outpatient facilities., Materials and Methods: AllGPs in NRW were asked to cooperate. Participating GPs filled out a questionnaire for each patient. The patients recorded the symptoms prompting the imaging examinations. The radiologists or other physicians performing the examinations were asked to provide the images and written reports and to complete a questionnaire. A file was created for each of the 394 patients with image documentation of at least one examination. Each file, which included medical history, physical findings, imaging documentation and written report, was sequentially forwarded to a board-certified radiologist and to a physician without board certification in radiology working in a university hospital and in an outpatient facility. All physicians were requested to complete a structured questionnaire for each file., Results: The referral diagnoses were rated as medically plausible in 81%, the indications for imaging found correct in 76%, the examination techniques considered appropriate in 69%, the clinical question answered in 63%, the interpretation judged medically correct in 50% and all incidental findings documented in 49%. In retrospect, 32 % of the examinations were judged superfluous. The sequence of multiple examinations performed on a particular patient was rated as appropriate in 51%. The interpretation revealed specialty-related differences. The plausibility of the referral diagnoses had a significant impact on the appropriateness of subsequent diagnostic investigations. Marked deficits showed sonography, performance by non-radiologists, self-referrals by GPs, gastroenterologic radiology and the ICD-10 coding (suspicion of cardiovascular disease)., Conclusion: In the "best-case" scenario, the process quality proved to have moderate deficiencies and the outcome quality severe deficiencies. In consequence, GPs and radiologists should be more communicative by sharing information and exchanging opinions. GP self-referrals should be restricted. Sonography and examinations performed by physicians without board certification in radiology should undergo stricter quality controls. A more intensive interdisciplinary collaboration is needed to determine the optimum implementation of diagnostic imaging of gastroenterologic and cardiovascular diseases.

Purpose: In the state of North-Rhine Westphalia (NRW), Germany, a survey was conducted on radiologic examinations ordered by general practitioners (GPs). Part I of this study aims to collect characteristic epidemiological data and to assess structural quality., Materials and Methods: All GPs in NRW were asked to cooperate. Participating GPs filled out a questionnaire for each patient. The patients recorded the symptoms prompting the imaging examinations. The radiologists or other physicians performing the examinations were asked to provide the images and written reports and to complete a questionnaire. Two university radiologists documented the pertinent test data from the submitted images and written records. Independently of each other, five university radiologists anonymously reviewed the image quality of each examination using structured questionnaires., Results: A total of 920 patients gave their informed consent and participated. Questionnaires from 787 patients, 852 GPs and 611 radiologists or other interpreting physicians as well as the complete survey data from 530 examinations were available. Of 1503 examinations, conventional radiography made up 52 %, sonography 17 %, computed tomography (CT) 13 % and magnetic resonance imaging (MRI) 5 %. Most indications involved the musculoskeletal (37 %) and respiratory systems (24 %). Physicians without board certification in radiology interpreted 1 % of the CT examinations, 26 % of the radiographic examinations and 71 % of the sonographic examinations. Of the 174 self-referrals, 1 % involved CT, 33 % conventional radiography and 66 % sonography. Written reports were available for 95 % of all 469 examinations performed by radiologists and 74 % of all 127 examinations conducted by non-radiologists. Only 44 % of the 23 sonographic studies were self-referrals by the patient's GP. On average, the radiographic techniques were acceptable in terms of diagnostic information and radiation hygiene. Conventional radiographs were better exposed when obtained by radiologists than by non-radiologists (p = 0.038). The delineation of anatomical structures was rated as good to acceptable for MRI, CT and conventional radiography, while the image quality was rated as diagnostically insufficient for sonography (p < 0.0001). The image quality of radiographic and sonographic examinations performed by radiologists was superior in comparison to examinations performed by physicians without board certification in radiology (p < 0.0001)., Conclusion: Examination technique and imaging quality of MRI, CT and conventional radiography performed on outpatients were in an acceptable diagnostic range, whereas the quality of sonography was inadequate.

The relation of dose and optical density in a conventional X-ray unit working with Screen Film Systems is subject to inherent fluctuations. For conventional equipment, the fluctuations of the components in conformity to the manufacturer instructions are calculated in such a fashion that the X-ray images of the patients fullfil the requirements of the Radiological Guidelines. The tolerance requirements of a mammogram can only be maintained if the operator runs the subsystem of film and processing such that the processing of films with single emulsion number remains over a longer period of time as close as possible to the manufacturer specifications for the type of film. The testing strategy used thus far in acceptance tests is the random sampling. In conventional X-ray units, and within the frame of constancy tests, this leads to an insufficiently accurate conclusion in case of exceeding tolerances of test-phantom images: of 99 images, 9 give a wrong result (rate of false negative + false positive). In mammography units, the introduction of stricter tolerances (delta D = +/- 0.15; desirable according to the "European Protocol for the Quality Control of the Physical and Technical Aspects of mammography Screening"), would further decrease this ratio: 37 of 99 images would give a wrong result. This forces to a different strategy of testing when the reference values are fixed for the image of a test phantom and for the constancy testing of film processing.

Stroke Units are specialised centers of expertise with the aim to optimize acute therapy of stroke. More specifically, the aims are (a) to reduce the area of brain infarction, (b) to prevent or appropriately react to complications, (c) to ensure an optimal strategy of secondary stroke prevention after having clarified etiopathogenesis, and (d) to establish a basis for subsequent rehabilitation. Stroke Units should collaborate for the evaluation and development of new diagnostic and therapeutic means. Patients' medical history, their clinical presentation and brain imaging create the basis for therapeutical decisions. The value of interventional therapy is presently evaluated for acute stroke therapy (e.g. intra-arterial thrombolysis) and secondary stroke prevention (Stent-protected angioplasty of carotid stenosis).

The influence of the tandem optics and the TV-tube to the image quality of 1k- and 2k-radiographs of a modern fluoroscopy equipment should be assessed on the basis of objective parameters and clinical requirements. Radiographs of different phantoms with 1k- and 2k-image matrix, different illumination point corrections (IPC) and signal gray levels were taken, examined and evaluated, in order to determine the objective image parameters and the clinical relevancy of these parameters. On the one hand, the digital images data could be used directly for evaluation; on the other hand, the radiographs could be visually evaluated by experienced radiologists within the framework of a blind study. The IPC is controlled by the aperture of the iris diaphragm and the insertion of a neutral gray filter in the tandem optics. The larger the aperture of the iris diaphragm (at constant image receiver dose) the higher were gradation, signal to noise ratio (SNR) and image homogeneity. Furthermore, the larger the aperture, the lower was the square wave response function (SWRF). The insertion of a gray filter in the tandem optics decreases gradation, SNR and homogeneity, and improves the SWRF.

Purpose: To evaluate how the training of radiology residents in taking radiographs influences the work of radiographers and the established quality standards., Methods: A first year radiology resident was trained for 4 weeks in focusing and exposure techniques by radiographers. In a second period the resident took 582 radiograms, which were compared with those taken by technicians for error estimation on a daily basis. During a third period the radiographs were produced in a contest between the resident and a skilled radiographer. Errors were analyzed by two independent experts according to established guidelines of the German Medical Association., Results: At the beginning of the second period the average error rate of the resident was 11.9% as compared to 8.9% in the technicians team, in the following month 9.2% versus 15.9%. In the third period no relevant difference in errors could be observed. Finally, unexpected quality improvements were implemented like an improved standardization of focusing and exposure techniques as well as dose reduction., Conclusions: Radiology residents easily learn focusing and exposure techniques and achieve comparable results as radiographers within a short period of time. The additionally achieved knowledge improves the technical process of taking radiographs. We recommend to include a two plane radiography training period in the curriculum of radiology residents. It reinforces the radiologist's role in continuous quality improvements of the diagnostic process.

Purpose: The aim of the study was to evaluate the current quality of the outpatient radiodiagnostic care of children and adolescents as demonstrated for the example of conventional X-ray procedures., Materials and Methods: A consecutive series of 166 outpatient X-rays, selected by fixed criteria, was analysed according to both diagnostic aspects and radiation protection., Results: The X-rays examined were mainly gathered from orthopedic and radiological practices and from hospital radiological departments. The majority of these outpatient X-rays showed significant deficiencies regarding exposure, appropriate field size, and focussing or positioning of the patient. After the evaluation of the 166 X-rays by a total-score, 25% (42/166) of the X-rays were considered to be diagnostically insufficient., Conclusions: Improvements in outpatient radiodiagnostics are necessary to ensure adequate radiodiagnostic care of children and adolescents.

Purpose: Analysis of reject films from a large radiological department under the following aspects: How big is the waste of films? Where are the sources of error? What are the possible means of quality assurance?, Material and Method: During a total period of 9 months, separated into three quarters, 14,570 reject films were analysed and assigned to 4 categories ("positioning", "exposure", "reject films due to patients" and "others"). In addition they were classified according to the respective parts of the body. The influence of a "study effect" was quantified by the analysis before and after information of staff., Results: The reject film rate in relation to all performed x-rays, was 9.0-13.2% of all the films taken during that period: of these, the failure rate (x-rays useless for diagnosis because of their bad quality) was between 54.2 and 57.5%. In this category, the main sources of error were positioning (55%) and exposure (34%). Surprisingly, the technical film waste amounted to 42.5-45.8% (not developed or preexposed films, x-rays of phantoms etc.)., Conclusion: Wasted films due to errors occurring during taking, as well as technical film waste, are unavoidable. Their proportion in relation to the total number of films should not exceed 8%. The main approach to reducing cost must be to cut down technical film waste.

Purpose: The aim of our study was to examine the quality and consistency of film viewing equipment and surroundings for radiological film viewing as stipulated by the recently released DIN 6856 standard specifications sheet., Methods: 107 film viewers in 43 locations in the Department of General Radiology (Hospital of the Goethe University in Frankfurt, Germany) were examined with regard to viewer brightness (intrinsic luminous intensity) uniformity of viewbox brightness, colour of fluorescence tubes, dimensions, adjustable filters, positioning of the viewers and ambient light level., Results: Requirements regarding brightness were met in 70%, whereas conditions regarding uniformity of brightness were fulfilled in only 27% and the required filters in only 20% of all cases., Conclusions: 89% of the examined film viewboxes did not comply with the strict specifications laid down in DIN 6856. The requirements regarding the ambient light level (recommended range 50-100 lx) were met by only 75% of the examined desks.

Purpose: The purpose of this study was to test a scoring system and its utility for the assessment of the clinical significance of radiological examinations., Material and Methods: The reports of all diagnostic studies obtained in patients with a clinical suspicion of pancreatitis, urinary tract obstruction, biliary or gallbladder diseases, ileus and gastrointestinal perforation were scored prospectively in 4 categories from 0 to 3. These categories were related to the ability to establish a definite diagnosis, to exclude suspected disease, to influence further diagnostic work-up and therapeutic decision-making., Results: This scoring system showed significant differences of the efficacy of different imaging modalities in these 5 clinical settings., Conclusion: This scoring system was helpful to determine the clinical significance of radiological examinations.

It is shown that the number of contrasts which can be differentiated on a radiograph depends on the detail size, the noise, and the viewing conditions. The minimum signal-to-noise ratio (SNR) for a perception approach is equivalently described by the SGA value. This testing method was first developed by De Belder and Bollen to examine the visibility of low contrast details. The correlation between the SGA and the speed class S of the system can be explained by this method.

With the introduction of the German industrial protocol for quality assurance of X-ray equipment, everybody using X-ray machines fell into some sort of trap or found some of the procedures misleading. Vigorous discussions were held on every conceivable aspect of this and other protocols, and are still in progress. This paper points out some of the common traps and considers a new type dosimeter, which allows a definite separation of quality assurance of X-ray equipment and of processing and which can also be used in future for quality assurance of digital radiography equipment.

The task of this committee on quality control and radiation protection is described, along with an explanation of the legal principles used in the execution of its duties (Nuclear Safety Law and Radiological Ordinance). Furthermore, the procedures used for the evaluation of X-rays are illustrated, followed by test films of X-ray equipment and film developers. Finally, the composition and activities of the Radiation Protection Committee are described.

Quality assurance for diagnostic imaging equipment has been successful so far. In the old Federal Republic of Germany, inspection of the existing equipment in diagnostic radiology in being completed. The estimated number of uninspected units is relatively small. All detected shortcomings have been repaired in the meantime, and very few faults have been detected in newly installed equipment. Of the status obtained following inspection and repair is to be maintained, however, more effective methods must be implemented. There is no doubt that everybody involved in quality assurance programs, including the experts and supervisory authorities, is actively working on improving the results.

A simple testing method for defining the average density or the integral density of x-ray images is described. In a semiquantitative way the physicians in radiological offices can measure the proper integral density. The amount of scattered x-rays influences the integral density significantly. Proper values for testing the integral density of x-ray images are described.

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 visual method is an alternative for examining whether film processing and the x-ray equipment are in accordance with the provisions of subsection 16 of the Federal German X-ray Ordinance (Roentgenverordnung). By this alternative it is possible to dispense with the densitometer and the sensitometer. Workday-to-workday or weekly control exposure of the grey scales is performed by means of the x-ray equipment, the dose being maintained at a constant level. The grey scale produced in this manner is compared with a reference scale; this ensures continual monitoring of the dose-density relation. Errors of the apparatus and errors during developing, or of the film, can be recognised separately due to double-sided measurement of the dose (entrance dose of the test sample and exit or film dose).

Properly exposed radiographs and under- or overexposed ones were processed differently with regard to temperature and time. Using a step wedge for the objective estimation, the alteration of well-exposed radiographs by neglecting time and temperature control was examined. Further information is given about the possibility to improve the quality of wrongly exposed radiographs by manipulation of the processing, and about the quantity of acceptable radiographs received in this way. Stop bath, fixation bath, wash bath and drying were performed regularly. The result showed, that the only chance to get high quality radiographs is by exact and correct working.

The Federal German Board of Physicians ("Bundesärztekammer") has recently issued guide principles for quality assurance in x-ray diagnosis. These include the basic measurements defining important image details, sensitivity of screen-film combinations and exposure times. The conditions required for meeting the guide principles were tested, using low contrast grids for simulating tissues. Practical consequences from these measurements for radiographic techniques and for the use of test grids in quality assurance are detailed.

The radiation burden of an individual patient caused by a radiological examination depends strongly on the technical parameters, such as kV and mAs. As an inquiry among 150 swiss physicians showed, rather different irradiation techniques are used for the same examination. Depending on these irradiation techniques, the doses may vary by almost a factor of ten. These large variations in dose indicate that in some clinics or hospitals the radiographic techniques and the film processing are at fault. This fact has to be accounted for by future efforts of quality assurance in diagnostic radiology.

The Working Group for Standardisation justifies and comments on the establishment of a standard series for image quality assurance in X-ray diagnostic services (DIN 6868). In order to promote compliance with these standards, the users are given some background information on the structure of the standard series and on the recommended procedures to be followed. The definitions for the various hierarchically arranged tests, such as constancy test, status test, acceptance test as well as a definition for the term "base-line image quality" are explained.