Diagnostic accuracy of digitized chest X-rays using consumer-grade color displays for low-cost teleradiology services: a multireader-multicase comparison.

INTRODUCTION: In teleradiology services and in hospitals, the extensive use of visualization displays requires affordable devices. The purpose of this study was to compare three differently priced displays (a medical-grade grayscale display and two consumer-grade color displays) for image visualization of digitized chest X-rays. MATERIALS AND METHODS: The evaluated conditions were interstitial opacities, pneumothorax, and nodules using computed tomography as the gold standard. The comparison was accomplished in terms of receiver operating characteristic (ROC) curves, the diagnostic power measured as the area under ROC curves, accuracy in conditions classification, and main factors affecting accuracy, in a factorial study with 76 cases and six radiologists. RESULTS: The ROC curves for all of the displays and pathologies had similar shapes and no differences in diagnostic power. The proportion of cases correctly classified for each display was greater than 71.9%. The correctness proportions of the three displays were different (p<0.05) only for interstitial opacities. The evaluation of the main factors affecting these proportions revealed that the display factor was not significant for either nodule size or pneumothorax size (p>0.05). CONCLUSIONS: Although the image quality variables showed differences in the radiologists' perceptions of the image quality of the three displays, significant differences in the accuracy did not occur. The main effect on the variability of the proportions of correctly classified cases did not come from the display factor. This study confirms previous findings that medical-grade displays could be replaced by consumer-grade color displays with the same image quality.

Agreement and reading time for differently-priced devices for the digital capture of X-ray films.

We assessed the reliability of three digital capture devices: a film digitizer (which cost US $15,000), a flat-bed scanner (US $1800) and a digital camera (US $450). Reliability was measured as the agreement between six observers when reading images acquired from a single device and also in terms of the pair-device agreement. The images were 136 chest X-ray cases. The variables measured were the interstitial opacities distribution, interstitial patterns, nodule size and percentage pneumothorax size. The agreement between the six readers when reading images acquired from a single device was similar for the three devices. The pair-device agreements were moderate for all variables. There were significant differences in reading-time between devices: the mean reading-time for the film digitizer was 93 s, it was 59 s for the flat-bed scanner and 70 s for the digital camera. Despite the differences in their cost, there were no substantial differences in the performance of the three devices.

Comparison between differently priced devices for digital capture of X-ray films using computed tomography as a gold standard: a multireader-multicase receiver operating characteristic curve study.

OBJECTIVE: Film digitizers are a specialized technology that is available for scanning X-ray radiographs; however, their cost makes them unaffordable for developing countries. Thus, less expensive alternatives are used. The purpose of this study was to compare three devices for digital capture of X-ray films: a film digitizer (US $15,000), a flatbed scanner (US $1800), and a 10-megapixel digital camera (US $450), in terms of diagnostic accuracy, defined as the area under the receiver operating characteristic curves and computed tomography as the gold standard. MATERIALS AND METHODS: The sample included 136 chest X-ray cases with computed tomography confirmation of the presence or absence of pneumothorax, interstitial opacities, or nodules. The readers were six radiologists who made observations of eight variables for each digital capture of the X-ray films: three main variables to determine the accuracy in the detection of the above-mentioned pathologies, four secondary variables to categorize other pathological classifications, and one variable regarding digital image quality. RESULTS: The receiver operating characteristic curves for each device and pathology were very similar. For the main variables, there was no significant statistical difference in diagnostic accuracy between the devices. For the secondary variables, >84% of cases were correctly classified, even those that were classified with the lowest image quality. High accuracy was determined for the three main variables (0.75 to 0.96), indicating good performance for all tested devices, despite their very different prices. CONCLUSIONS: Choosing a device for a teleradiology service should involve additional factors, such as capture time, maintenance concerns, and training requirements.

Financing a large-scale picture archival and communication system.

RATIONALE AND OBJECTIVES: An attempt to finance a large-scale multi-hospital picture archival and communication system (PACS) solely based on cost savings from current film operations is reported. MATERIALS AND METHODS: A modified Request for Proposal described the technical requirements, PACS architecture, and performance targets. The Request for Proposal was complemented by a set of desired financial goals-the main one being the ability to use film savings to pay for the implementation and operation of the PACS. RESULTS: Financing of the enterprise-wide PACS was completed through an operating lease agreement including all PACS equipment, implementation, service, and support for an 8-year term, much like a complete outsourcing. Equipment refreshes, both hardware and software, are included. Our agreement also linked the management of the digital imaging operation (PACS) and the traditional film printing, shifting the operational risks of continued printing and costs related to implementation delays to the PACS vendor. An additional optimization step provided the elimination of the negative film budget variances in the beginning of the project when PACS costs tend to be higher than film and film-related expenses. CONCLUSION: An enterprise-wide PACS has been adopted to achieve clinical workflow improvements and cost savings. PACS financing was solely based on film savings, which included the entire digital solution (PACS) and any residual film printing. These goals were achieved with simultaneous elimination of any over-budget scenarios providing a non-negative cash flow in each year of an 8-year term.

Productivity and cost assessment of computed radiography, digital radiography, and screen-film for outpatient chest examinations.

An objective assessment and comparison of computed radiography (CR) versus digital radiography (DR) and screen-film for performing upright chest examinations on outpatients is presented in terms of workflow, productivity, speed of service, and potential cost justification. Perceived ease of use and workflow of each device is collected via a technologist opinion survey. Productivity is measured as the rate of patient throughput from normalized timing studies. The overall speed of service is calculated from the time of examination ordering as stamped in the radiology information system (RIS), to the time of image availability on the picture archiving and communication system (PACS), to the time of interpretation rendered (from the RIS). A cost comparison is discussed in terms of potential productivity gains and device expenditures. Comparative results of a screen-film (analog) dedicated chest unit versus a CR reader and a DR dedicated chest unit show a higher patient throughput for the digital systems. A mean of 8.2 patients were moved through the analog chest room per hour, versus 9.2 patients per hour using the CR system and 10.7 patients per hour with the DR system. This represents a 12% increase in patient throughput for CR over screen-film; a 30% increase in patient throughput for DR over screen-film, which is statistically significant; and a 16% increase in patient throughput for DR over CR, which is not statistically significant. Measured time to image availability for interpretation is much faster for both CR and DR versus screen-film, with the mean minutes to image availability calculated as 29.2 +/- 14.3 min for screen-film, 6.7 +/- 1.5 min for CR, and 5.7 +/- 2.5 min for DR. This represents an improved time to image availability of 77% for CR over screen-film, 80% for DR over screen-film, and 15% for DR over CR. These results are statistically significant (P <.0001) for both CR over screen-film and DR over screen-film but not statistically significant for DR over CR. A comparison of the digital technology costs illustrates that the high cost of DR may not be justifiable unless a facility has a steady high patient volume to run the device at or near 100% productivity. Both CR and DR can improve workflow and productivity over analog screen-film in a PACS for delivery of projection radiography services in an outpatient environment. Cost justification for DR over CR appears to be tied predominantly to high patient volume and continuous rather than sporadic use patterns.

Digital detectors in mammography. A technological overview.

At a first glance the future of digital mammography seems very bright considering the wealth of offerings for new detectors, made by companies on the market or in journals. However technically spoken, digital mammography is one of the most demanding applications in the spectrum of radiology along with a high degree of cost consciousness in the mammography screening programs. The functional requirements are so high for digital mammography that only the best and most expensive components are good enough to compete with the current screen-film systems. Next difficulties are the lack of quality standards for digital detectors, not at all existing in the past and still under discussion, and the non-existence or changing of approval procedures. This is discouraging the industries to enter the field and is slowing down the phase-in time. After these obstacles are removed, there will come the discussions on acceptance of digital mammography within the professional community, due to the 'look' of the images and also the need to gain confidence with these images.

[The economic expediency of digital fluorography]. / Ekonomicheskaia tselesoobraznost' tsifrovoi fliuorografii.

The paper shows the advantages of digital versus routine film fluorography, which allows a user to make a choice of the type of an apparatus for fluorographic examination. The expenses of a fluorographic room on developing equipment and expendable materials for different types of the room's equipment. It gives the cost and specific features of the use of current film and digital fluorographs and the data on the cost of an examination using film and digital fluorography in case of the most cost-effective fluorographic systems.

An economic evaluation of the use of rare earth screens to reduce the radiation dose from diagnostic X-ray procedures in Israel.

In Israel the diffusion of rare earth screen technology has been limited. These screens could halve the radiation dose to the patient from diagnostic X-ray radiography, with little managerial effort and without being detrimental to the quality of the diagnostic image. We estimated the total effective dose from diagnostic film radiography capable of reduction by the use of rare earth screens, based on the number of hospital and ambulatory diagnostic X-ray procedures. This number was multiplied by the computed radiation dose per body site for a series of diagnostic procedures. The annual dose was approximately 0.53 mSv per head, approximately half of which could be averted by the introduction of rare earth screen technology. Based on a fatality risk of 3% Sv-1, it is estimated that the adoption of rare earth screen technology might reduce the annual incidence of cancer by some 93 cases, half of which would be fatal after an average latency period of 18.4 years. The cost of purchasing rare earth screens on a nationwide basis is approximately $3.0 million. This cost is outweighed by a saving of $9.6 million in X-ray tube replacement costs over the period 1997-2006. Government legislation enforcing the use of rare earth screens is essential, because of the lack of prestige associated with acquiring rare earth technology, as well as institutional reluctance to accept the external benefits of reduced morbidity and mortality and/or to extend budgetary time horizons.

Technical aspects of twin screen-film chest radiography: cost effective lung and mediastinal imaging.

OBJECTIVE: To determine the sensitometry and 'cross-talk' of a twin screen-film cassette and to assess its clinical potential. MATERIALS AND METHODS: The twin cassette utilises two sets of screens, divided by filter material, to provide an optimised image of the mediastinum and the lungs. The exposure difference for the two images was measured sensitometrically. The contribution to film density of visible light and K-characteristic radiation, from adjacent screens in the absence of a dividing filter, was investigated. RESULT: Clinical experience indicated that an exposure difference of 3.4 between the front and back screens, was optimal. Visible light and K-characteristic radiation from the front screens, contributed up to 20 and 24% respectively, of the back film exposure and screen absorbed energy respectively. This was reduced to 0 and 6% with the use of the filter. CONCLUSIONS: The twin screen-film cassette provides extended latitude to enable optimal visualisation of the lung and mediastinal regions. Adjacent screen 'cross-talk' has been overcome to allow standard and portable chest applications.

Clinical evaluation of twin screen-film chest radiography: cost effective lung and mediastinal imaging.

OBJECTIVE: A new twin screen-film cassette system optimised for conventional chest radiography was evaluated by four thoracic radiologists. MATERIALS AND METHODS: The twin screen-film cassette system produces two film images, the front film optimised for the mediastinal region of the chest, the rear for the lung region. Image degradation on either screen-film system due to internal photon scatter has been virtually eliminated due to the use of a dividing filter. Fifty patients were included in a trial that resulted in a set of chest images for each patient, taken on the same inspiration, by both the twin screen-film cassette and the conventional system. The resultant fifty sets of images were evaluated by four chest radiologists who scored 12 radiographic features of the chest and patient pathologies present, using a paired difference technique. RESULTS: The image quality of the twin screen-film cassette system was judged to be significantly superior to the conventional screen-film system in nine of the 12 radiographic features scored (P < 0.003). In the three other regions and for the patient pathologies, no significant conclusions were drawn. CONCLUSION: The new twin screen-film system showed improved visualisation of radiographic features, particularly in the mediastinal and retrocardiac lung regions. This new system shows promise in both standard and portable clinical applications.

[Digital radiography. Cost-benefit analysis]. / Digitale Radiographie. Kosten-Nutzenanalyse.

Due to its high dynamic range and contrast discernibility, digital radiography offers substantial advantages compared with conventional film-screen systems. Moreover, further advantages can be assumed for radiation protection. Digital radiography also allows conventional image data to be included in PACS (Picture Archiving Communication System). These well-known advantages are faced with legal questions which are not yet settled. Cost effectiveness in using systems of digital radiography and PACS are also under discussion. By means of examining economic efficiency and cost analysis of digital radiography systems, economic effectiveness was assessed. This was also compared with conventional alternatives. As a result, it may be assumed that amortization is reached in three to four years. Based on lower costs for films, digital systems are more cost effective than conventional systems after this period.

Soft-copy computed radiography in neonatal and pediatric intensive care units: cost-savings analysis.

PURPOSE: To determine whether soft-copy interpretation of computed radiography (CR) in neonatal and pediatric intensive care units (ICUs) can result in a cost savings compared with screen-film radiography for the radiology department. MATERIALS AND METHODS: The actual cost of CR equipment, maintenance contracts, and the estimated cost for data storage were compared with the potential savings that could result from eliminating film, decreasing the number of librarians and lost radiographs, and improving technologists' efficiency. RESULTS: After the 1st year, net cash flow from use of soft-copy CR interpretation is projected to result in a slight savings for the radiology department but not enough to offset the capital equipment purchase price. CONCLUSION: Soft-copy CR ICU imaging will not result in a cost savings. To have a balanced net cash flow would require either more than doubling potential savings or decreasing capital equipment cost by greater than one-half. The justification for soft-copy CR needs to be judged by its effect on increasing physician efficiency and timely decisions on patient care.

[New analog and digital imaging techniques for chest diagnosis--principles--clinical value--economics]. / Neue analoge und digitale Bildaufnahme-verfahren zur Thorax-diagnostik. Prinzip--klinische Wertigkeit--Wirtschaftlichkeit.

For chest imaging new analog and digital imaging techniques are now available. In this publication the imaging methods conventional film/screen, asymmetric film/screen("In-Sight"), slit(AMBER)-technique, spotfilm(100 mm)-technique, storage phosphor radiography and digital image intensifier radiography are compared. The clinical value is discussed by measured imaging capabilities and patient examinations. The highest image quality was demonstrated by the slit(AMBER)-technique. In comparison to conventional film/screen, storage phosphor radiography and asymmetric film/screen was graded higher only in the mediastinal field. Because of the low spatial resolution the image quality of digital image intensifier radiography was classified too poor for chest imaging.

[An economic comparison between digital luminescence radiography and conventional film processing in intensive care medicine]. / Wirtschaftlichkeitsvergleich zwischen Digitaler Lumineszenzradiographie und konventioneller Filmverarbeitung in der Intensivmedizin.

The costs of a conventional film-screen radiography daylight-system and storage-phosphor computed radiography (Fuji AC-1) are compared. In 1990, 3841 radiologic procedures (mostly portable chest X-rays) were performed in 3474 patients of a surgical intensive care unit. With conventional film-screen radiography 6.8% retakes were necessary for diagnostic or technical reasons. Comparing the fixed and variable costs of both systems conventional film-screen radiography was more economic under the given conditions of the test. It is concluded that computed radiography in intensive care patients has definite advantages in terms of image quality and reproducibility, however, in order to compete successfully in the economic turf CR has to be implemented in a picture archiving and communication system (PACS).

Large-screen image intensifier photofluorography compared with full-size screen-film technique in chest radiography.

Large-screen image intensifier photofluorography revealed a radiation dose and exposure time of about one third of those of a medium speed rare-earth screen/film (Trimax T4/XD) combination for full-size chest radiography. The resolving power of the former technique is somewhat poorer and there is a moderate electron-òptical distortion in the peripheral field. In clinical chest radiography photospot films showed excellent demonstration of the central areas of the image but slight deterioration in peripheral parts. The minification effect of the photofluorographic films is advantageous for visual perception of many anatomic details on chest radiographs. The type of viewing device for photospot films is important.