New technology in radiological diagnosis: An investigation of diagnostic image quality in digital displays of radiographs

Digital radiology is undergoing rapid evolution. Its objectives can be summarized as the creation within the modern radiology department - and indeed within the entire hospital - of a harmonious, integrated, electronic network capable of handling all diagnostic radiological images, obviating the need for conventional film-based radiology. One of the limiting factors in the introduction and exploitation of digital technology is the issue of image display quality: if electronic display systems are to be widely used for primary radiological diagnosis, it is essential that the diagnostic quality of the displayed images should not be compromised. From the perspective of the practising radiologist, this study examines the performance of the first two commercially available digital radiological display systems to be purchased and installed in a British hospital. This work incorporates an extensive observer performance investigation of image quality from existing 1024- and 1280-line display systems, and suggests that displayed images digitized at a pixel size of 210?m show a significant reduction in diagnostic performance when compared with original film. Such systems appear to be unsuitable for primary radiological diagnosis of subtle lesions. Some of the physical properties of such systems, some relevant methodological issues, and the relationship between image quality and other factors influencing the development acceptance and implementation of digital technology, have also been investigated; the results are presented. This is a controversial subject, and conflicting views have been expressed in the British literature concerning the issue of whether or not the technology is now ready for total system implementation; the view of this author is that careful testing of display systems, and of every other component of digital networks, should precede their entry into clinical use

Diseases of the Chest, Breast, Heart and Vessels 2019-2022

This open access book focuses on diagnostic and interventional imaging of the chest, breast, heart, and vessels. It consists of a remarkable collection of contributions authored by internationally respected experts, featuring the most recent diagnostic developments and technological advances with a highly didactical approach. The chapters are disease-oriented and cover all the relevant imaging modalities, including standard radiography, CT, nuclear medicine with PET, ultrasound and magnetic resonance imaging, as well as imaging-guided interventions. As such, it presents a comprehensive review of current knowledge on imaging of the heart and chest, as well as thoracic interventions and a selection of "hot topics". The book is intended for radiologists, however, it is also of interest to clinicians in oncology, cardiology, and pulmonology

Diseases of the Chest, Breast, Heart and Vessels 2019-2022

This open access book focuses on diagnostic and interventional imaging of the chest, breast, heart, and vessels. It consists of a remarkable collection of contributions authored by internationally respected experts, featuring the most recent diagnostic developments and technological advances with a highly didactical approach. The chapters are disease-oriented and cover all the relevant imaging modalities, including standard radiography, CT, nuclear medicine with PET, ultrasound and magnetic resonance imaging, as well as imaging-guided interventions. As such, it presents a comprehensive review of current knowledge on imaging of the heart and chest, as well as thoracic interventions and a selection of "hot topics". The book is intended for radiologists, however, it is also of interest to clinicians in oncology, cardiology, and pulmonology

Evaluation of factors that affect contrast-detail in digital X-Ray and computed tomography

The central aim of this project was to develop a new methodology of evaluation and optimisation of image quality based on low contrast-detail (LCD) detectability performance of computed tomography (CT). This method is well established in digital radiography however similar tool of image evaluation and quality optimisation for CT images are not available. In comparison with other image evaluation methods in digital radiography, the tool of LCD detectability performance—particularly the automated approach—is a good choice for image quality optimisation. This method helps to determine appropriate exposure factors to provide optimum image quality while maintaining a lower radiation dose to patients. This method is a straightforward and direct way to assess image quality as it provides quantitative evaluations of low contrast and small detail measurements of medical images. The subjectivity of image evaluation methods based on human observers is avoided via automated scoring software that is utilised in automated approach of LCD detectability performance. The trade-offs between perceived image quality, diagnosis efficacy and exposure dose can be determined by LCD detectability measurements. A newly designed LCD CT (CDCT) phantom was manufactured and dedicated software was developed with the cooperation of Artinis Medical Systems (Zetten, The Netherlands) for the new evaluation method of LCD detectability. The specifications of the phantom design were optimised based on the standard recommendations of phantom manufacturing and the requirements of the proposed new evaluation methodology. The CT inverse image quality figure (CTIQFinv) was determined as a measure of LCD detectability performance of CT images. An equation was developed and implemented in the software to calculate and objectively measure CTIQFinv values. The new proposed method of LCD detectability performance was validated by evaluating the influences of exposure factors kVp and mAs, slice thicknesses and object location on image quality in terms of CTIQFinv values based on software and radiographers’ scoring results. The results showed that the new evaluation methodology-based CDCT phantom, along with the automated measurement of CTIQFinv value, had generally shown to be consistent with a prior knowledge of image quality in relation to change of mAs, kVp and slice thickness settings. This work showed that the CDCT phantom and the measurement of CTIQFinv values can provide a measure of CT image quality in terms of LCD detectability performance. This method has a promising role for CT image evaluation and optimisation, and has the potential to effectively evaluate the effects of protocol parameters on image quality of different CT scanners and systems. Future changes to the phantom design and/or software is required to overcome some of the current limitation

Patient radiation dose issues resulting from the use of CT in the UK

In this report, COMARE presents a comprehensive review of the radiation dose issues associated with CT scans in the UK. The implications of the increase in the numbers of CT scans in the UK are considered in the report, with focus on the number of younger patients undergoing CT scans, who have greater sensitivity to x-rays. The report provides an update on the radiation protection aspects of justification (balancing risk and benefit) and optimisation (balancing the risk from the radiation dose with the quality of the image)

Asbestos fibers and other elongate mineral particles: state of the science and roadmap for research

"The National Institute for Occupational Safety and Health (NIOSH) considers asbestos to be a potential occupational carcinogen and recommends that exposures be reduced to the lowest feasible concentration. As the federal agency responsible for conducting research and making recommendations for the prevention of worker injury and illness, NIOSH has undertaken a reappraisal of how to ensure optimal protection of workers from exposure to asbestos fibers and other EMPs. As a first step in this effort, NIOSH convened an internal work group to develop a framework for future scientific research and policy development. The NIOSH Mineral Fibers Work Group prepared a first draft of this State of the Science and Roadmap for Scientific Research (herein referred to as the Roadmap), summarizing NIOSH's understanding of occupational exposure and toxicity issues concerning asbestos fibers and other EMPs."-- p. . iii. Introduction -- 2. Overview of current issues -- 3. Framework for research -- 4. The Path forward -- 5. References -- 6. GlossaryDepartment of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health."March 2011."Also available via the World Wide Web as an Arobat .pdf file (3.69 MB, 173 p.).Includes bibliographical references (p. 101-127)