Bone Integration and Prevalence of Radiolucent Lines around the Pegs of Minimally Cemented Glenoid Components in Total Shoulder Arthroplasty / Integração óssea e prevalência de linhas radiotransparentes ao redor dos pinos de componentes glenoidais minimamente cimentados na artroplastia total de ombro

Abstract Objectives Glenoid component failure is the main cause of total shoulder arthroplasty (TSA) revision, and component design seems to influence the failure rate. The aim of the present study was to clinically and radiographically (through X-rays and computed tomography scan) evaluate the results of TSA using a minimally cemented glenoid component. Methods Total should arthroplasties performed using the minimally cemented Anchor Peg (DuPuy Synthes, Warsaw, IN, USA) glenoid component between 2008 and 2013 were evaluated. University of California at Los Angeles (UCLA) scores were calculated, and standardized plain film and computed tomography images were obtained, at a minimum follow-up of 24 months. The presence of bone between the fins of the central component peg, which indicates its integration, was assessed on the images, as well the presence of radiolucent lines around the glenoid component. Results Nineteen shoulders in 17 patients were available for evaluation. According to the UCLA score, clinical results were satisfactory in 74% of cases and fair in 21% of cases. One patient had a poor result. Component integration was found in 58% of patients (total in 42% and partial in 16%). Radiolucent lines were observed in 52% of cases. No relationship was detected between component integration and clinical results. Conclusion Satisfactory clinical results were achieved in most patients undergoing TSA using a minimally cemented glenoid component. Radiolucent lines around the glenoid component are common, but do not interfere with the clinical results. Level of evidence IV; Case series; Treatment study.

Resumo Objetivos A falha do componente glenoidal é a principal causa de revisão da artroplastia total do ombro (ATO) e sua frequência parece ser influenciada pelo design do componente. O objetivo deste estudo foi a avaliação clínica e radiográfica (através de raios X e tomografia computadorizada) dos resultados da ATO com componente glenoidal minimamente cimentado. Métodos O presente trabalho analisou ATOs realizadas com componente glenoidal Anchor Peg (DuPuy Synthes, Warsaw, IN, EUA) minimamente cimentado entre 2008 e 2013. Por um período mínimo de acompanhamento de 24 meses, escores segundo critérios da University of California at Los Angeles (UCLA) e imagens padronizadas de radiografia simples e tomografia computadorizada foram analisadas. A presença de osso entre as aletas do pino do componente central, que é um indicador de sua integração, foi avaliada nas imagens, bem como a presença de linhas radiotransparentes ao redor do componente glenoidal. Resultados Dezenove ombros de 17 pacientes foram avaliados. De acordo com o escore da UCLA, os resultados clínicos foram satisfatórios em 74% dos casos e moderados em 21% dos casos. O resultado foi ruim em um paciente. A integração de componentes foi observada em 58% dos pacientes, sendo total em 42% e parcial em 16% dos casos. Linhas radiotransparentes foram observadas em 52% dos pacientes. Nenhuma relação entre a integração de componentes e os resultados clínicos foi detectada. Conclusão A maioria dos pacientes submetidos à ATO com componente glenoidal minimamente cimentado apresentou resultados clínicos satisfatórios. Linhas radiotransparentes ao redor do componente glenoidal são comuns, mas não interferem nos resultados clínicos Nível de evidência IV; Série de caso; Estudo terapêutico.

Brazilian young dental practitioners' use and acceptance of digital radiographic examinations

PURPOSE: The aim of this study was to investigate the use and acceptance of digital radiographic examinations by Brazilian dental practitioners in daily practice and to evaluate the advances that have occurred over the past 5 years. MATERIALS AND METHODS: Dental practitioners enrolled in extension courses at the Piracicaba Dental School, University of Campinas, Brazil, responded to a self-administered questionnaire in the years 2011 and 2015. They were asked about sociodemographic factors and their knowledge and use of digital radiographic examinations. Descriptive analysis was performed, as well as the chi-square and Fisher exact tests, with a significance level of 5% (α=0.05). RESULTS: A total of 181 participants responded to the questionnaire in the years 2011 and 2015. Most of the respondents worked in private practice, had graduated within the last 5 years, and were between 20 and 30 years old. In 2011, 55.6% of respondents reported having ever used digital radiographic examinations, while in 2015 this number increased significantly to 85.4% (p<.0001), out of which 71.4% preferred it to conventional images. Moreover, 21.4% of respondents reported having used digital radiographic examinations for more than 3 years. A significant increase in use of intraoral digital radiography (p=0.0316) was observed in 2015. In both years, image quality and high cost were indicated, respectively, as the main advantage and disadvantage of digital radiographic examinations. CONCLUSION: This study showed that digital radiology has become more common in Brazil over the past 5 years. Most of the Brazilian dental practitioners evaluated in 2015 used digital radiographic examinations.

Evaluation of Obstructive Pulmonary Function Impairment Risks in Pulmonary Emphysema Detected by Low-Dose CT: Compared with Simple Digital Radiography / 결핵및호흡기질환

BACKGROUND: Pulmonary emphysema (PE) is major cause of obstructive pulmonary function impairment (OPFI), which is diagnosed by spirometry. PE by high resolution CT is known to be correlated with OPFI. Recently, low dose CT (LDCT) has been increasingly used for screening interstitial lung diseases including PE. The aim of this study was to evaluate OPFI risks of subjects with PE detected by LDCT compared with those detected by simple digital radiography (SDR). METHODS: LDCT and spirometry were administered to 266 inorganic dust exposed retired workers, from May 30, 2007 to August 31, 2008. This study was approved by our institutional review board and informed consent was obtained. OPFI risk was defined as less than 0.7 of forced expiratory volume in one second (FEV1)/forced vital capacity (FVC), and relative risk (RR) of OPFI of PE was calculated by multiple logistic regression analysis. RESULTS: Of the 266 subjects, PE was found in 28 subjects (10.5%) by LDCT and in 11 subjects (4.1%) by SDR; agreement was relatively low (kappa value=0.32, p<0.001). FEV1 and FEV1/FVC were significantly different between PE and no PE groups determined by either SDR or LDCT. The differences between groups were larger when the groups were divided by the findings of SDR. When PE was present in either LDCT or SDR assays, the RRs of OPFI were 2.34 and 8.65, respectively. CONCLUSION: LDCT showed significantly higher sensitivity than SDR for detecting PE, especially low grade PE, in which pulmonary function is not affected. As a result, the OPFI risks in the PE group by LDCT was lower than that in the PE group by SDR.

The importance of radiation quality for optimisation in radiology

Selection of the appropriate radiation quality is an important aspect of optimisation for every clinical imaging task in radiology, since it affects both image quality and patient dose. Spreadsheet calculations of attenuation and absorption have been applied to basic imaging tasks to provide an assessment of imaging performance for a selection of phosphors used in radiology systems. Contrast, which is an important component of image quality affected by radiation quality, has been assessed in terms of the contrast to noise ratio (CNR) for a variety of X-ray beams. Both CNR and patient dose fall with tube potential, and selection of the best option is a compromise that will provide an adequate level of image quality with as low a radiation dose as practicable. It is important that systems are set up to match the response of the imaging phosphor, as there are significant differences between phosphors. For example, the sensitivity of barium fluorohalides used in computed radiography declines at higher tube potentials, whereas that of gadolinium oxysulphide used in rare earth screens increases. Addition of 0.2 mm copper filters, which can reduce patient entrance surface dose by 50%, may be advantageous for many applications in radiography and fluoroscopy. The disadvantage of adding copper is that tube output levels have to be increased. Application of simple calculations of the type employed here could prove useful for investigating and assessing the implications of potential changes in X-ray beam quality prior to implementation of new techniques.

Digital Chest Radiography with an Amorphous Silicon Flat-Panel-Detector Versus a Storage-Phosphor System: Comparison of Soft-Copy Images

PURPOSE: We compared the soft-copy images produced by an amorphous silicon flat-panel-detector system with the images produced by a storage-phosphor radiography system for their ability to visualize anatomic regions of the chest. MATERIALS AND METHODS: Two chest radiologists independently analyzed 234 posteroanterior chest radiographs obtained from 78 patients on high-resolution liquid crystal display monitors (2560x2048x8 bits). In each patient, one radiograph was obtained with a storage-phosphor system, and two radiographs were obtained via amorphous silicon flat-panel-detector radiography with and without spatial frequency filtering. After randomizing the 234 images, the interpreters rated the visibility and radiographic quality of 11 different anatomic regions. Each image was ranked on a five-point scale (1 = not visualized, 2 = poor visualization, 3 = fair visualization, 4 = good visualization, and 5 = excellent visualization). The statistical difference between each system was determined using the Wilcoxon's signed rank test. RESULTS: The visibility of three anatomic regions (hilum, heart border and ribs), as determined by the chest radiologist with 14 years experience (p<0.05) and the visibility of the thoracic spine, as determined by the chest radiologist with 8 years experience (p=0.036), on the amorphous silicon flat-panel-detector radiography prior to spatial frequency filtering were significantly superior to that on the storage-phosphor radiography. The visibility of 11 anatomic regions, as determined by the chest radiologist with 14 years experience (p<0.0001) and the visibility of five anatomic regions (unobscured lung, rib, proximal airway, thoracic spine and overall appearance), as determined by the chest radiologist with 8 years experience (p<0.05), on the amorphous silicon flat-panel-detector radiography after spatial frequency filtering were significantly superior to that on the storage-phosphor radiography. CONCLUSION: The amorphous silicon flat-panel-detector system depicted the anatomic structures on chest radiographs comparably or significantly better as compared to the storage-phosphor system. The superiority of the amorphous silicon flat-panel-detector system compared to the storage-phosphor system was more obvious after performing spatial frequency filtering.

Screen-Film Mammography and Soft-Copy Full-Field Digital Mammography: Comparison in the Patients with Microcalcifications

OBJECTIVE: We wanted to compare the ability of screen-film mammography (SFM) and soft-copy full-field digital mammography (s-FFDM) on two different monitors to detect and characterize microcalcifications. MATERIALS AND METHODS: The images of 40 patients with microcalcifications (three patients had malignant lesion and 37 patients had benign lesion), who underwent both SFM and FFDM at an interval of less than six months, were independently evaluated by three readers. Three reading sessions were undertaken for SFM and for FFDM on a mammography-dedicated review workstation (RWS, 2K x 2.5K), and for FFDM on a high-resolution PACS monitor (1.7K x 2.3K). The image quality, breast composition and the number and conspicuity of the microcalcifications were evaluated using a three-point rating method, and the mammographic assessment was classified into 4 categories (normal, benign, low concern and moderate to great concern). RESULTS: The image quality, the number and conspicuity of the microcalcifications by s-FFDM (on the RWS, PACS and both) were superior to those by SFM in 85.0%, 80.0% and 52.5% of the cases, respectively (p 0.01). The mammographic assessment category for the microcalcifications in the three reading sessions was similar. CONCLUSION: s-FFDM gives a superior image quality to SFM and it is better at evaluating microcalcifications. In addition, s-FFDM with the PACS monitor is comparable to s-FFDM with the RWS for evaluating microcalcifications.

Optimization of Digital Mammography Resolution Using Magnification Technique in Computed Radiography

PURPOSE: To determine whether magnified digital mammography using a computed radiography system can produce better spatial resolution by reducing the focus-object distance, and to define the optimal magnification factor when a large x-ray tube focal spot is used for digital mammography using a CR system. MATERIALS AND METHODS: Digital images obtained using computed radiography of a breast phantom were obtained using various magnification factors. Up to twelve acrylic blocks each measuring one centimeter in height were used to increase the distance between the breast phantom and the base plate (screen holder), in order to create the magnification images. The large (0.3 mm) focal spot of the x-ray tube was used for the entire series of images. Three radiologists participated in the evaluation of the images, in order to determine which had the best resolution. The resolving ability of the line pair structures and image clarity of the detectable artificial microcalcifications (specs) were the two factors used to determine the resolution of the images. The images were not compressed aFnd the viewing conditions, including the magnification factors, brightness and contrast, were fixed. The images were displayed on four high resolution PACS dedicated monitors (5 mega pixel LCD, BARCO Belgium). RESULTS: A focus-object distance of 590 mm and a source-to-image receptor distance of 650 mm (set by the manufacturer) resulted in the best resolution, when combined with a magnification factor of 1.1. All three radiologists agreed on this result. Two of the radiologists believed that at least two more line pairs were better separated on the magnified image having the best resolution than on the unmagnified image, while one radiologist believed that three more line pairs were better separated on this magnified image. Using images with still larger magnification factors did not improve the resolution due to edge blurring. It was easier to determine the resolving power by means of the line-pair structures than by assessing the clarity of the artificial microcalcifications (specs). A 10% decrease in focal spot-object distance resulted in a 21% increase in radiation to the breasts. CONCLUSION: Magnified digital breast images taken with a computed radiography system using a large focal spot produced better quality images, because of their utilizing more pixels per volume of the breast phantom with a minimal increase in radiation dosage.

Liquid-Crystal Display Monitors and Cathode-Ray Tube Monitors: A Comparison of Observer Performance in the Detection of Small Solitary Pulmonary Nodules

OBJECTIVE: To compare observer performance using liquid-crystal display (LCD) and cathode-ray tube (CRT) monitors in the interpretation of soft-copy chest radiographs for the detection of small solitary pulmonary nodules. MATERIALS AND METHODS: By reviewing our Medical Center's radiologic information system, the eight radiologists participating in this study (three board-certified and five resident) retrospectively collected 40 chest radiographs showing a solitary noncalcified pulmonary nodule approximately 1 cm in diameter, and 40 normal chest radiographs. All were obtained using a storage-phosphor system, and CT scans of the same patients served as the gold standard for the presence of a pulmonary nodule. Digital images were displayed on both high-resolution LCD and CRT monitors. The readers were requested to rank each image using a five point scale (1 = definitely negative, 3 = equivocal or indeterminate, 5 = definitely positive), and the data were interpreted using receiver operating characteristic (ROC) analysis. RESULTS: The mean area under the ROC curve was 0.8901+/-0.0259 for the LCD session, and 0.8716+/-0.0266 for the CRT session (p > 0.05). The reading time for the LCD session was not significantly different from that for the CRT session (37.12 and 41.46 minutes, respectively; p = 0.889). CONCLUSION: For detecting small solitary pulmonary nodules, an LCD monitor and a CRT monitor are comparable.

The Diagnosis of Small Solitary Pulmonary Nodule: Comparison of Standard and Inverse Digital Images on a High-Resolution Monitor using ROC Analysis

PURPOSE: To study the impact of inversion of soft-copy chest radiographs on the detection of small solitary pulmonary nodules using a high-resolution monitor. MATERIALS AND METHODS: The study group consisted of 80 patients who had undergone posterior chest radiography; 40 had a solitary noncalcified pulmonary nodule approximately 1 cm in diameter, and 40 were control subjects. Standard and inverse digital images using the inversion tool on a PACS system were displayed on high-resolution monitors (2048x2560x8 bit). Ten radiologists were requested to rank each image using a five-point scale (1=definitely negative, 3=equivocal or indeterminate, 5=definite nodule), and the data were interpreted using receiver operating characteristic (ROC) analysis. RESULTS: The area under the ROC curve for pooled data of standard image sets was significantly larger than that of inverse image sets (0.8893 and 0.8095, respectively; p0.05). CONCLUSION: For detecting small solitary pulmonary nodules, inverse digital images were significantly inferior to standard digital images.

Determination of the Size of an Imaging Data Storage Device at a Full PACS Hospital

PURPOSE: To determine the appropriate size of a short and long-term storage device, bearing in mind the design factors involved and the installation costs. MATERIALS AND METHODS: The number of radiologic studies quoted is the number of these undertaken during a one-year period at a university hospital with 650 beds, and reflects the actual number of each type of examination performed at a full PACS hospital . The average daily number of outpatients was 1,586, while that of inpatients was 639.5. The numbers of radiologic studies performed were as follows: 378 among 189 outpatients, and 165 among 41 inpatients. The average daily number of examinations was 543, comprising 460 CR, 30 ultrasonograms, 25 CT, 8 MRI, and 20 others. RESULTS: The total amount of digital images was 17.4 GB Per day, while the amount of short-term data with lossless compression was 6.7 GB Per day. During 14 days short-term storage, the amount of image data was 93.7 GB in disk array. The amount of data stored mid term (1 year), with lossy compression, was 369.1 GB. The amount of data stored in the form of long-term cache and educational images was 38.7 GB and 30 GB, respectively. The total size of disk array was 531.5 GB. A device suitable for the long-term storage of images, for at least five years, requires a capacity of 1845.5 GB. CONCLUSION: At a full PACS hospital with 600 beds, the minimum disk space required for the short-and mid-term storage of image data in disk array is 540 GB. The capacity required for long term storage(at least five years) is 1900 GB.

Impact of Image Post-Processing on PACS Workstation: Dynamic Range Suppression(DRS) of Chest Radiographs

PURPOSE: To investigate the impact of post-processing on a PACS workstation before and after use of thedynamic range suppression method for the normal chest radiographs. MATERIALS AND METHODS: Forty normal chestradiographs of healthy adult volunteers aged 20 to 33 (average 27; M:F = 29:11) were acquired by FCR using adigital interface and then transferred to an in-house-developed PACS workstation. The image size of computed chestradiographs was 7.5MB with 1760 x 2140 matrix. An image enhancement processing named DRS, developed by theauthors, was applied to the acquired images and generated a total of 40 chest radiographs. These were presented tothree groups of observers, each consisting of one radiologist and one technician on the PACS workstation, whichhad two monitors of 1712 x 2100 resolution. So that external light would not affect the visibility of imagesduring observation, these were displayed in a light-controlled room. The J.J.Vucich method, suitably modified, wasused to evaluate the anatomical structures and physical parameters of processed and unprocessed radiographs. Usinga percentage scale, the observers evaluated both anatomical sections (seven anatomical items : cortical margins ofribs, left diaphragms, thoracic vertebrae, trachea, pulmonary vasculature, trabeculae of ribs and clavicle,diaphragm outline) and physical sections (four items : contrast, graininess, density, detail). The results for thethree groups, both before and after DRS processing, were then compared. RESULTS: There was a statisticallysignificant difference between the three groups: in the anatomical section, 78.64 before DRS and 82.55 after ; andin the physical section, 75.48 and 79.78 (p<0.05). The average values of all items were 77.06 before DRS and 81.17after (p<0.05). CONCLUSION: Post-processing of computed chest radiographs on the PACS workstation improves boththe visibility of anatomical features and general image quality. Thus, in a PACS environment, it can be a usefultool for enhancing the diagnostic efficacy of radiography.

Impact of Image Post-Processing on PACS Workstation: Dynamic Range Suppression(DRS) of Chest Radiographs

PURPOSE: To investigate the impact of post-processing on a PACS workstation before and after use of thedynamic range suppression method for the normal chest radiographs. MATERIALS AND METHODS: Forty normal chestradiographs of healthy adult volunteers aged 20 to 33 (average 27; M:F = 29:11) were acquired by FCR using adigital interface and then transferred to an in-house-developed PACS workstation. The image size of computed chestradiographs was 7.5MB with 1760 x 2140 matrix. An image enhancement processing named DRS, developed by theauthors, was applied to the acquired images and generated a total of 40 chest radiographs. These were presented tothree groups of observers, each consisting of one radiologist and one technician on the PACS workstation, whichhad two monitors of 1712 x 2100 resolution. So that external light would not affect the visibility of imagesduring observation, these were displayed in a light-controlled room. The J.J.Vucich method, suitably modified, wasused to evaluate the anatomical structures and physical parameters of processed and unprocessed radiographs. Usinga percentage scale, the observers evaluated both anatomical sections (seven anatomical items : cortical margins ofribs, left diaphragms, thoracic vertebrae, trachea, pulmonary vasculature, trabeculae of ribs and clavicle,diaphragm outline) and physical sections (four items : contrast, graininess, density, detail). The results for thethree groups, both before and after DRS processing, were then compared. RESULTS: There was a statisticallysignificant difference between the three groups: in the anatomical section, 78.64 before DRS and 82.55 after ; andin the physical section, 75.48 and 79.78 (p<0.05). The average values of all items were 77.06 before DRS and 81.17after (p<0.05). CONCLUSION: Post-processing of computed chest radiographs on the PACS workstation improves boththe visibility of anatomical features and general image quality. Thus, in a PACS environment, it can be a usefultool for enhancing the diagnostic efficacy of radiography.

Computed Radiogra p hy in Skeletal Imaging: Visual Assessment of Compressed Image Quality

PURPOSE: To evaluate the effect of lossy image compression on skeletal images and to determine the compression ratio which does not lead to difficulties when images are interpreted for diagnostic purposes. MATERIALS AND METHODS: Thirty-two computed radiographs (CR) of osteolytic bone tumors were obtained from Picture Archiving and Communication System. They were compressed to three different levels (Q factor 30, 70, 120) using the JPEG (Joint Photographic Expert Group) technique. Ninety-six pairs of uncompressed and compressed images were randomly ordered and then serially displayed on two high-resolution monitors. During a side-by-side review, three radiologists independently compared each pair of uncompressed and compressed images, and these were rated once using a five-category ordinal scale for tumor-related findings, linear structures, and soft tissues. The reviewers were then obliged to decide which image in each pair was of better quality, and finally, they were asked to evaluate the influence of image compression on diagnostic accuracy. RESULTS: The reviewers found no significant difference in image quality between uncompressed and compressed images with a Q factor 30. Compressed images with a Q factor of 70 or 120, however, revealed clinically relevant degradation. Among 96 observations of compressed images, 15 with a Q factor of 70 and 35 with a Q factor of 120 were considered inadequate for clinical purposes. CONCLUSION: If the JPEG technique is used, compressed CR skeletal images with a Q factor of 30 are acceptable for clinical application. Compressed images with a Q factor of 70 or 120 may, however, cause diagnostic difficulty and thus cannot be used for clinical purposes.

Detectability of the Mediastinal Lines: Comparison of Conventional Film-Screen Radiography and DigitalRadiography

PURPOSE: Using dynamic range compression (DRC) processing, this study compared the detectability ofmediastinal lines by conventional film screen rediography (FS) and by storage phosphor digital radiography(DR). MATERIALS AND METHODS: We selected 200 normal consecutive chest radiographs (100 FS, 100 DR) ; dynamic rangecompression was applied to DR processing and moving grids were used in both systems. Seven mediastinal lines (leftfaraspinal, right paraspinal, azygoesophageal, left para-aortic, posterior junctional, anterior junctional andright paratracheal) were scored from 0 point to 3 point(0:not visible, 1:suspiciously visible, 2:visible, but notclear, 3: clearly visible) according to visibility and sharpness, as agreed by a radiologist and a resident. Thedifferences between the two modalities were compared and analyzed by chi-square test. RESULTS: Among the 1400mediastinal lines analyzed, 419 lines by DR(59.9%) and 232 lines by FS(33.1%) were scored more than 2 points. Inall mediastinal lines except the left para-aortic, DR was more detectable and clearer than FS, with statisticalsignificance(P<.01). CONCLUSION: DR processed with DRC visualizes mediastinal lines more frequently and clearlythan conventional FS, and is therefore thought to be useful for the evaluation of mediastinal diseases.

Dysphagia Following Stroke: Evaluation with Digital Radiography

PURPOSE: To evaluate the usefulness of digital radiography in the assessment of dysphagia following stroke. MATERIALS AND METHODS: Eighteen stroke patients (8 men, 10 women) referred for dysphagia and ten controls without known pharyngeal swallowing difficulty underwent digital radiography using a 1:1 mixture of barium and water. We evaluated oropharyngeal transit time and the location and severity of dysphagia; transit time was defined as the time from the first movement of the bolus to the return of the epiglottis to its original position. We sought to observe specific patterns of oropharyngeal dysfunction; dysphagia was classified as mild, moderate, or severe. RESULTS: In the control group, oropharyngeal transit time was 1.25sec (1.0-1.5sec), and for dysphagia patients, this was 4.32sec (1.75-6.5sec). Eleven patients (61%) had oral dysfunction, and 12 (67%), pharyngeal dysfunction; eight (44%) showed both oral and pharyngeal dysfunction. Mild swallowing difficulties occurred in six patients (33%), moderate dysfunction in six (33%), and severe dysfunction in three (17%). CONCLUSION: The dynamic image of the pharynx, as seen on a digital radiograph, may be diagnostically useful for defining the location and severity of dysphagia; in order to make feeding recommendations, this information is essential.

High-Resolution PACS Work station: Diagnostic Performance and Comparison with Laser-Printed CR Films in Chest Diseases

OBJECTIVES: To compare the diagnostic performance of a high-resolution picture archiving and communications system (PACS) workstation directly interfaced with computed radiography(CR) with laser-printed CR films in chest diseases. MATERIALS AND METHODS: Chest radiographs with (n=91) and without (n=25) abnormalities were included. Atotal of 100 abnormalities from 91 radiographs consisted of irregular lines, pneumothoraces, nodules and consolidations (25 of each). Laser-printed hard copies with dynamic range compression (DRC) were produced. InPACS, soft copies of 1760 X 2140 X 10 bits CR images were displayed on 1536 X 2048 with 8 bit gray-scale monitors.The performance of four observers was compared between laser-printed hard copies and CR images displayed on a workstation according to receiver operating characteristic analysis. RESULTS: Overall, no significant difference sin observer performance were observed between laser-printed hard copies and CR images displayed on a workstation(p=.2454). Even though statistically not significant, the former was slightly superior to the latter for lesions of irregular lines, pneumothoraces, and consolidations, whereas for nodules, the latter was slightly better than the former. CONCLUSION: The diagnostic performance of a high-resolution PACS workstation in chest radiographs is acceptable and comparable to CR hard copies printed with DRC processing mode.