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

Managing technological change in a military treatment facility: a case study of medical diagnostic imaging support (MDIS) system

Picture archiving and communication system (PACS) represents an enormously expensive technological innovation in digital imaging which has the potential to alter the way in which radiology is practiced. The purpose of this thesis is to provide a better understanding of the requirements for PACS technology and the implementation of information systems in medical facilities. The objective of PACS technology is to improve access to radiographic images and reports throughout medical facilities while decreasing the cost of image production and storage. Medical Diagnostic Imaging Support (MDIS) system is the military tri-service project to install PACS in selected U.S. military medical treatment facilities (MTF) in an attempt to create a totally filmless environment. This thesis includes a case study of the implementation of the MDIS system at Madigan Army Medical Center and the change management issues that surround the introduction of an information system in a health care organization. The issues brought forth in this study are derived from two change models in the implementation of information systems.http://archive.org/details/managingtechnolo1094542869U.S. Navy (USN) authorApproved for public release; distribution is unlimited

Optimisation of the digital radiographic imaging of suspected non-accidental injury.

Aim: To optimise the digital (radiographic) imaging of children presenting with suspected non-accidental injury (NAI).;Objectives: (i) To evaluate existing radiographic quality criteria, and to develop a more suitable system if these are found to be inapplicable to skeletal surveys obtained in suspected NAI. (ii) To document differences in image quality between conventional film-screen and the recently installed Fuji5000R computed radiography (CR) system at Great Ormond Street Hospital for Children, (iii) To document the extent of variability in the standard of skeletal surveys obtained in the UK for suspected NAI. (iv) To determine those radiographic parameters which yield the highest diagnostic accuracy, while still maintaining acceptable radiation dose to the child, (v) To determine how varying degrees of edge-enhancement affect diagnostic accuracy. (vi) To establish the accuracy of soft compared to hard copy interpretation of images in suspected NAI.;Materials and Methods: (i) and (ii) Retrospective analysis of 286 paediatric lateral spine radiographs by two observers based on the Commission of European Communities (CEC) quality criteria, (iii) Review of the skeletal surveys of 50 consecutive infants referred from hospitals throughout the United Kingdom (UK) with suspected NAI. (iv) Phantom studies. Leeds TO. 10 and TO. 16 test objects were used to compare the relationship between film density, exposure parameters and visualisation of object details, (iv) Clinical study. Anteroposterior and lateral post mortem skull radiographs of six consecutive infants were obtained at various exposures. Six observers independently scored the images based on visualisation of five criteria, (v) and (vi) A study of diagnostic accuracy in which six observers independently interpreted 50 radiographs from printed copies (with varying degrees of edge-enhancement) and from a monitor.;Results: The CEC criteria are useful for optimisation of imaging parameters and allow the detection of differences in quality of film-screen and digital images. There is much variability in the quality and number of radiographs performed as part of skeletal surveys in the UK for suspected NAI. The Leeds test objects are either not sensitive enough (TO. 10) or perhaps over sensitive (TO. 16) for the purposes of this project. Furthermore, the minimum spatial resolution required for digital imaging in NAI has not been established. Therefore the objective interpretation of phantom studies is difficult. There is scope for reduction of radiation dose to children with no effect on image quality. Diagnostic accuracy (fracture detection) in suspected NAI is generally low, and is not affected by image display modality.;Conclusions: The CEC quality criteria are not applicable to the assessment of clinical image quality. A national protocol for skeletal surveys in NAI is required. Dedicated training, close supervision, collaboration and consistent exposure of radiologists to cases of NAI should improve diagnostic accuracy. The potential exists for dose reduction when performing skeletal surveys in children and infants with suspected NAI. Future studies should address this issue

Digital pathology in clinical use: where are we now and what is holding us back?

Whole slide imaging is being used increasingly in research applications and in frozen section, consultation and external quality assurance practice. Digital pathology, when integrated with other digital tools such as barcoding, specimen tracking and digital dictation, can be integrated into the histopathology workflow, from specimen accession to report sign-out. These elements can bring about improvements in the safety, quality and efficiency of a histopathology department. The present paper reviews the evidence for these benefits. We then discuss the challenges of implementing a fully digital pathology workflow, including the regulatory environment, validation of whole slide imaging and the evidence for the design of a digital pathology workstation

Validation of radiographic automatic exposure control device testing in the era of filmless radiography : and new variables associated with testing

The exposure needed for a clinically useful image requires much less precision when using digital radiography (DR) than when using screen/film (SF) radiography. The Automatic Exposure Control (AEC) device was developed for ensuring accurate and precise exposures with SF technology. This thesis evaluates the importance of the AEC device in DR. Several tests were performed to evaluate the operation of the AEC devices. A performance test was used to measure variation associated with different tube potentials and phantom thicknesses. The criteria used for the performance test was dependent on the imaging device manufacturer. A balance test measured variation among detectors within the AEC device. The criteria used for the balance test was dependent on the imaging device manufacturer. A reproducibility test measured variation among exposure values when no changes were made to the testing materials. The reproducibility test was considered acceptable if the coefficient of variation was found to be less than or equal to 5%. A density test was used to measure the amount of user-selectable adjustment to the exposure. Tolerance for this adjustment was a 20 to 50% change in the exposure per step. The appropriateness of the exposure was examined using an Exposure Index (EI) range test. The criteria used for the EI range test was dependent on the imaging device manufacturer. Finally, the overall operation of each AEC device was examined. An AEC was determined to be functioning properly if it passed all above stated tests. Roughly a quarter of devices failed the performance test. One-third of the AEC devices failed the balance test. No AEC device failed the reproducibility test. Roughly 60% of the AEC devices failed the density test. Approximately 60% of the AEC devices failed the EI range test. Overall, nearly 80% of all AEC devices tested failed one or more test. There was no significant difference in the table AEC devices versus the upright AEC devices. More than three-fourths of AEC devices used with Cassette Radiography (CR) failed at least one test. All Direct Digital Radiography (DDR) systems failed at least one AEC test. Although the importance of AEC devices has shifted from ensuring good image quality to maintaining appropriate patient exposures, the research performed in this thesis confirms AEC device calibration is still important for patient care. This paper also demonstrates the need for updated AEC testing methods developed for use with CR and DDR

The effect of the introduction of picture archive and communication systems (PACS) on patient radiation doses and patient management

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 20/12/2000.This thesis considers the effects of Picture Archive and Communications Systems (PACS), on both patient radiation doses and patient management. PACS is a relatively new technology which acquires, transmits, and stores radiological images digitally. This thesis investigates the doses which are required to produce radiographic images which are acceptable to radiologists and referring clinicians, and compares these doses with those required for the film/screen systems which they are replacing. A review of the literature shows that despite claims of dose reductions, very little good evidence exists about dose changes with the introduction of PACS. A comparison of images of test objects indicates that the images are comparable under limited conditions, that PACS has a much wider latitude than film (>250 mAs), and that contrast detail improves with increase in exposure. Two original observational studies are described in which PACS and film doses are compared for examinations of two groups of adult patients. The results indicate that the doses for PACS equate to those used with a 300 speed film/screen system thus necessitating dose increases of around 30% for the majority of adult patients in the UK. The issue of whether the number of images which are repeated, with additional patient doses, due to unsatisfactory images (rejected images), or unavailability of the images when clinically required (lost images), is addressed and indicates that PACS may allow a dose saving of 1.1 % and 1.4% respectively. The overall result of these studies indicates that the widespread introduction of PACS is likely to increase population doses. Two original studies which consider patients within the Accident and Emergency department are described. These studies aim to produce evidence to justify the introduction of the new technology, despite higher radiation doses, by identifying improvements in patient management which might improve patient outcomes. The results of these studies provide little evidence of such benefits to patients. This thesis concludes that the use of current PAC systems produces an increase in the radiation dose to the adult population in the UK, without demonstrable improvements in patient management

Spinoff 1997: 25 Years of Reporting Down-to-Earth Benefits

The 25th annual issue of NASA's report on technology transfer and research and development (R&D) from its ten field centers is presented. The publication is divided into three sections. Section 1 comprises a summary of R&D over the last 25 years. Section 2 presents details of the mechanisms NASA uses to transfer technology to private industry as well as the assistance NASA provides in commercialization efforts. Section 3, which is the focal point of the publication, features success stories of manufacturers and entrepreneurs in developing commercial products and services that improve the economy and life in general

Applications of satellite technology to broadband ISDN networks

Two satellite architectures for delivering broadband integrated services digital network (B-ISDN) service are evaluated. The first is assumed integral to an existing terrestrial network, and provides complementary services such as interconnects to remote nodes as well as high-rate multicast and broadcast service. The interconnects are at a 155 Mbs rate and are shown as being met with a nonregenerative multibeam satellite having 10-1.5 degree spots. The second satellite architecture focuses on providing private B-ISDN networks as well as acting as a gateway to the public network. This is conceived as being provided by a regenerative multibeam satellite with on-board ATM (asynchronous transfer mode) processing payload. With up to 800 Mbs offered, higher satellite EIRP is required. This is accomplished with 12-0.4 degree hopping beams, covering a total of 110 dwell positions. It is estimated the space segment capital cost for architecture one would be about $190M whereas the second architecture would be about$250M. The net user cost is given for a variety of scenarios, but the cost for 155 Mbs services is shown to be about $15-22/minute for 25 percent system utilization

Information Technologies for the Healthcare Delivery System

That modern healthcare requires information technology to be efficient and fully effective is evident if one spends any time observing the delivery of institutional health care. Consider the observation of a practitioner of the discipline, David M. Eddy, MD, PhD, voiced in Clinical Decision Making, JAMA 263:1265-75, 1990, . . .All confirm what would be expected from common sense: The complexity of modern medicine exceeds the inherent limitations of the unaided human mind. The goal of this thesis is to identify the technological factors that are required to enable a fully sufficient application of information technology (IT) to the modern institutional practice of medicine. Perhaps the epitome of healthcare IT is the fully integrated, fully electronic patient medical record. Although, in 1991 the Institute of Medicine called for such a record to be standard technology by 2001, it has still not materialized. The author will argue that some of the technology and standards that are pre-requisite for this achievement have now arrived, while others are still evolving to fully sufficient levels. The paper will concentrate primarily on the health care system in the United States, although much of what is contained is applicable to a large degree, around the world. The paper will illustrate certain of these pre-requisite IT factors by discussing the actual installation of a major health care computer system at the University of Rochester Medical Center (URMC) in Rochester, New York. This system is a Picture Archiving and Communications System (PACS). As the name implies, PACS is a system of capturing health care images in digital format, storing them and communicating them to users throughout the enterprise