26 8.5. Principles and clinical application of multi-resolution image processing in computed radiography Presenter: Motohiro Tabuchi, Dojinkai Konko hospital, Japan Author: Motohiro Tabuchi Introduction: Medical X-ray imaging creates processed images with subjective contrast. In screen film (SF) systems it is difficult to depict images if the subjective contrast is very high. For example, the thorax contains lungs (high radiolucency) and bone (low radiolucency) and therefore has very high subjective contrast, which results in missing information due to the performance limits of SF systems. On the other hand, computed radiography (CR) systems can work more flexibly than SF systems by using frequency processing for images with very high levels of contrast. To solve this problem, CR systems employ sharpening processing in order to depict a wide range of contrast with a low gradation, using high pass filters that suppress fluctuation of the direct current (DC) component between local images. Before development of CR systems, two output methods were used which preserved the DC component to approximate SF images and sharpened images with high pass filters. However, this style of processing was not universally adopted due to a feeling of degraded reliability created by resampling images with a coarse reading pitch and by using an artificial signal in imaging processing. Therefore, even though improvements in reading the sampling pitch and obtaining actual-sized images have been made, the present mainstream method is just an iteration of former methods that were used to approximate SF. This paper proposes that images that are mainly composed of an alternating current (AC) component are valid for clinical detection of abnormalities also seen in X-ray images that use a fluctuating DC component, such as in X-ray images of the thorax. Methods: Three kinds of multi-resolution images were processed by changing the addition ratio of the original images. Subjective evaluation was performed through a questionnaire survey of 10 clinicians and receiver operating curve (ROC) analysis. Conclusions: The majority of examinees preferred reading conventional images. However, ROC analysis denotes that the proposed method improved recognition performance for detection of abnormalities. This paper proposes that more active use of variable frequency properties of CR systems can help clinicians depict a wide range of image resolutions with a low gradation. This method is effective in images with high subjective contrast such as those of the thorax. 8.6. Abnormal incidents concerning x-ray in healthcare, cases reported to Finnish Radiation and Nuclear Safety Authority (STUK) Presenter: Elina Hallinen, Finnish Radiation and Nuclear Safety Authority (STUK) Author: Elina Hallinen Introduction: According to the Finnish Radiation Degree (1512/1991) section 17 deals with notifications of abnormal events (abnormal incidents) as follows “STUK shall be notified of the following without delay: any abnormal event pertaining to the use of radiation that is substantially detrimental to safety at the place where the radiation is used or in its environs, or any other abnormal observation or information of essential significance for the radiation safety of workers or the environment.” Until 2010 the frequency of reported incidences concerning x-rays in healthcare was approximately one reported case every other year. Since then the amount of reports has risen due to active promotion for reporting the incidences. In year 2013 total of 64 cases of abnormal incidences were reported concerning x-ray in healthcare. In this oral presentation statistics and individual cases of reported abnormal incidents are presented. Methods: Each abnormal incidence is reported individually. Necessary additional information is requested and/or actions are taken by STUK. Statistics of the reported abnormal incidents are drawn. Results: There have not been reported incidences, which would have required intervention by STUK. Statistics of types of events, causes of the events, exposed parties, exposure levels etc. can be drawn. The reported abnormal incidents in the past few years have given a moderate view and understanding of what kind of processes are vulnerable to failures. Individual cases can be used for educational purposes to enhance radiation safety. 8.7. Is My Digital X-Ray Image Acceptable For Diagnosis? Presenter: Philip Ballinger, The Ohio State University, U.S.A Author: Philip W. Ballinger Introduction: We routinely ask ourselves; Is my image acceptable? The question when viewing a digital x-ray image can have multiple answers. To assist in answering, phantom and patient images are analyzed and reviewed to provide examples regarding how the image is affected by pathology, proper and inadequate collimation, use of lead shielding, positioning and other operator controlled situations. Current literature reports cases where radiographers may overexpose a region of interest and use post-processing to “center” and show a “properly positioned patient”. Multiple phantom images are reviewed to show how images can be adjusted and the differences between CR and DR images. The basics of using collimation, lead rubber and consistency of the operator are also demonstrated. The four basic exposure index values used by the major equipment manufacturers are compared and contrasted which show the direct and indirect relations used which further leads to confusion between radiographers in different facilities and countries. Methods: Reviewing patient images and creating images using phantoms, the limits and limitations of digital radiographic equipment are identified and interpreted. Conclusions/Results: If improperly used, digital radiographic equipment can produce images for diagnosis with increased radiation exposure to the patient while compromising the quality of the image. 8.8. Does e-learning prepare radiographers to provide a preliminary clinical evaluation for musculoskletal trauma images? Presenter: Beverly Snaith, Mid Yorkshire Hospitals NHS Trust, Wakefield, UK Authors: Snaith B; Lewis E; Lancaster A; Flintham K; Hardy M Introduction: In the UK radiographers are expected to contribute to trauma decision making through preliminary clinical evaluation (commenting). Evidence has shown that lack of confidence and training are perceived barriers to the implementation of commenting. A strategy to address this has been the development of an online training package (e- LfH Image Interpretation) by the CoR and DH. This paper reports the initial findings from a single centre study to evaluate the effectiveness of this training in preparing radiographers to participate in commenting. It will specifically focus on the pre-learning assessment of knowledge and language used by radiographers when writing their comments. Methods: A prospective pre-test/post-test design was used with online questionnaires to identify radiographers’ self-reported confidence and image interpretation tests. Outcome measures include sensitivity, specificity and comment content analysis. Results: The sample included 18 radiographers each interpreting 2 banks of up to 50 musculoskeletal trauma cases in simulated clinical conditions. Initial analysis demonstrated marked variation in structure and length of comments. Common errors and correlation between confidence and accuracy will be reported. Content analysis provides additional insight into use of terminology and recognition of incidental findings. Post-test analysis will demonstrate the potential role of e-learning and is ongoing. 8.9. Self-assessment of wrist radiographs Presenter: Susanne Kivistö, Oulu University Hospital, Finland Authors: Susanne Kivistö, Ullamari Kuismin,Tarja Holtinkoski, Terhi Nevala Introduction: The purpose of this self-assessment project was to improve the quality of wrist radiography so that possible erroneous assessments in patient treatment, caused by inferior projections, could be minimised and high-quality, diagnostic radiographs could be produced. In an internal audit of the Emergency Radiology Unit, attention was focused on overly long image areas and inaccurate projections in orthopaedic radiography. Radiologists had received feedback from the clinics because of inferior wrist radiographs. Also, self-assessment as a part of quality control had been brought up during training arranged by the Society of Radiographers in Finland. All of these issues contributed to the initiation of selfassessment in the Emergency Radiology Unit of OUH (Oulu University Hospital) in the spring of 2012. Methods: The leaders of the self-assessment project first acquired information on what self-assessment means and what it is based on. The
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