Could standardising commercial off-the-shelf (COTS) monitors to the DICOM part 14: GSDF affect clinical diagnosis? A visual grading characteristics analysis (original) (raw)
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Dentomaxillofacial Radiology, 2013
Objectives: To investigate whether standardizing commercial off-the-shelf (COTS) display devices to the digital imaging and communications in medicine part 14: greyscale standard display function (DICOM part 14: GSDF) would affect the presentation of dental images. Methods: Two COTS display devices from the radiology department of a dental teaching hospital and a laptop computer monitor for reference were calibrated to conform to DICOM part 14: GSDF. Four dental surgeons and two final-year students undertook a relative visual grading analysis of the two devices before and after calibration, under control of the viewing environment. Results: Calibrating COTS display devices to conform to the DICOM part 14: GSDF and viewing under reduced ambient light result in a consistent, perceived visual sensation for the presented radiological image. The area under the visual grading characteristics curve (AUC VGC ) before calibration is 0.62 CI (0.56, 0.68) and AUC VGC after calibration is 0.51 CI (0.45, 0.57). Conclusions: Standardizing COTS display devices to the DICOM part 14: GSDF can improve image presentation.
Objectives: To investigate whether standardizing commercial off-the-shelf (COTS) display devices to the digital imaging and communications in medicine part 14: greyscale standard display function (DICOM part 14: GSDF) would affect the presentation of dental images. Methods: Two COTS display devices from the radiology department of a dental teaching hospital and a laptop computer monitor for reference were calibrated to conform to DICOM part 14: GSDF. Four dental surgeons and two final-year students undertook a relative visual grading analysis of the two devices before and after calibration, under control of the viewing environment. Results: Calibrating COTS display devices to conform to the DICOM part 14: GSDF and viewing under reduced ambient light result in a consistent, perceived visual sensation for the presented radiological image. The area under the visual grading characteristics curve (AUC VGC ) before calibration is 0.62 CI (0.56, 0.68) and AUC VGC after calibration is 0.51 CI (0.45, 0.57). Conclusions: Standardizing COTS display devices to the DICOM part 14: GSDF can improve image presentation.
La Radiologia medica, 2018
To evaluate the effects of display pixel pitch and maximum luminance on intra- and inter-observer reproducibility and observer performance when evaluating chest lesions and bone fractures. This was a multi-institutional study for a retrospective interpretation of selected digital radiography images. Overall, 82 images were selected by senior radiologists, including 50 cases of chest lesions and 32 cases of bone fractures. These images were displayed at two pixel pitches (0.212 and 0.165 mm size pixels) and two maximum luminance values (250 and 500 cd/m) and reviewed twice by senior and junior radiologists. All the observers had to indicate the likelihood of the presence of the lesions and to rate the relative confidence of their assessment. Cohen Kappa statistic was computed to estimate the reproducibility in correctly identifying lesions; for multi-reader-multi-case (MRMC) analysis, weighted Jackknife Alternative Free-response Receiver Operating Characteristic (wJAFROC) statistical...
Comparison of Color LCD and Medical-grade Monochrome LCD Displays in Diagnostic Radiology
Journal of Digital Imaging, 2007
In diagnostic radiology, medical-grade monochrome displays are usually recommended because of their higher luminance. Standard color displays can be used as a less expensive alternative, but have a lower luminance. The aim of the present study was to compare image quality for these two types of displays. Images of a CDRAD contrast-detail phantom were read by four radiologists using a 2-megapixel (MP) color display (143 cd/m 2 maximum luminance) as well as 2-MP (295 cd/m 2 ) and 3-MP monochrome displays. Thirty lumbar spine radiographs were also read by four radiologists using the color and the 2-MP monochrome display in a visual grading analysis (VGA). Very small differences were found between the displays when reading the CDRAD images. The VGA scores were j0.28 for the color and j0.25 for the monochrome display (p=0.24; NS). It thus seems possible to use color displays in diagnostic radiology provided that grayscale adjustment is used.
Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2009
Objectives. The aim of this study was to evaluate if different ways of adjusting brightness and contrast of monitors with different technical standards influence the diagnosis of carious lesions in digital radiographs. Study design. One hundred extracted teeth (premolars and molars) were radiographed. Seven observers evaluated images for approximal carious lesions on 3 monitors: a standard color monitor with brightness and contrast manually adjusted for viewing radiographs, a Digital Imaging and Communication in Medicine (DICOM) part 14 precalibrated color monitor, and a DICOM part 14 precalibrated monochromatic monitor. All evaluations were made in ambient light Ͻ50 lux. Receiver operating characteristic curves were plotted to evaluate results. The standard criterion was a histologic examination of sliced teeth. Kappa statistic evaluated intraobserver agreement. Results. No significant difference in accuracy of approximal carious lesion diagnosis was found between the monitors. Intraobserver agreement varied between fair and good. Conclusion. No differences that could affect clinicians' abilities to detect carious lesions in digital radiographs existed between the standard monitor and the color and monochrome DICOM part 14 precalibrated monitors.
Psychophysical evaluation of calibration curve for diagnostic LCD monitor
Radiation Medicine, 2006
Purpose. In 1998, Digital Imaging Communications in Medicine (DICOM) proposed a calibration tool, the grayscale standard display function (GSDF), to obtain output consistency of radiographs. To our knowledge, there have been no previous reports of investigating the relation between perceptual linearity and detectability on a calibration curve. Materials and methods. To determine a suitable calibration curve for diagnostic liquid crystal display (LCD) monitors, the GSDF and Commission Internationale de l'Eclairage (CIE) curves were compared using psychophysical gradient δ and receiver operating characteristic (ROC) analysis for clinical images. Results. We succeeded in expressing visually recognized contrast directly using δ instead of the just noticeable difference (JND) index of the DICOM standard. As a result, we found that the visually recognized contrast at low luminance areas on the LCD monitor calibrated by the CIE curve is higher than that calibrated by the GSDF curve. On the ROC analysis, there was no significant difference in tumor detectability between GSDF and CIE curves for clinical thoracic images. However, the area parameter Az of the CIE curve is superior to that of the GSDF curve. The detectability of tumor shadows in the thoracic region on clinical images using the CIE curve was superior to that using the GSDF curve owing to the high absolute value of δ in the low luminance range. Conclusion. We conclude that the CIE curve is the most suitable tool for calibrating diagnostic LCD monitors, rather than the GSDF curve.
Imaging Science in Dentistry
Purpose: This study aimed to assess the computer monitors used for analysis and interpretation of digital radiographs within the clinics of the Oral Health Centre of Western Australia. Materials and Methods: In total, 135 computer monitors (3 brands, 6 models) were assessed by analysing the same radiographic image of a combined 13-step aluminium step wedge and the Artinis CDDent 1.0 ® (Artinis Medical Systems B.V. ® , Elst, the Netherlands) test object. The number of steps and cylindrical objects observed on each monitor was recorded along with the monitor's make, model, position relative to the researcher's eye level, and proximity to the nearest window. The number of window panels blocked by blinds, the outside weather conditions, and the number of ceiling lights over the surgical suite/cubicle were also recorded. MedCalc ® version 19.2.1 (MedCalc Software Ltd ® , Ostend, Belgium, https://www.medcalc.org; 2020) was used for statistical analyses (Kruskal-Wallis test and stepwise regression analysis). The level of significance was set at P<0.05. Results: Stepwise regression analysis showed that only the monitor brand and proximity of the monitor to a window had a significant impact on the monitor's performance (P<0.05). The Kruskal-Wallis test showed significant differences (P<0.05) in monitor performance for all variables investigated, except for the weather and the clinic in which the monitors were placed. Conclusion: The vast performance variation present between computer monitors implies the need for a review of monitor selection, calibration, and viewing conditions. (Imaging Sci Dent 20200182
ROC Study of Four LCD Displays Under Typical Medical Center Lighting Conditions
Journal of Digital Imaging, 2006
Nine observers reviewed a previously assembled library of 320 chest computed radiography (CR) images. Observers participated in four sessions, reading a different 1/4 of the sample on each of four liquid crystal displays: a 2-megapixel (MP) consumer color display, a 2-MP business color display, a 2-MP medical-grade gray display, and a 3-MP gray display. Each display was calibrated according to the DICOM Part 14 standard. The viewing application required observer login, then randomized the order of the subsample seen on the display, and timed the responses of the observer to render a 1Y Y5 judgment on the absence or presence of ILD on chest CRs. Selections of 1Y Y2 were considered negative, 3 was indeterminate, and 4Y Y5 were positive. The order of viewing sessions was also randomized for each observer. The experiment was conducted under controlled lighting, temperature, and sound conditions to mimic conditions typically found in a patient examination room. Lighting was indirect, and illuminance at the display face was 195 T 8% lux and was monitored over the course of the experiment. The average observer sensitivity for the 2 MP color consumer, 2 MP business color, 2 MP gray, and 3 MP gray displays were 83.7%, 84.1%, 85.5%, and 86.7%, respectively. The only pairwise significant difference was between the 2-MP consumer color and the 2-MP gray (P = 0.05). Effect of order within a session was not significant (P = 0.21): period 1 (84.3%), period 2 (86.2%), period 3 (85.4%), period 4 (84.1%). Observer specificity for the various displays was not statistically significant (P = 0.21). Finally, a timing analysis showed no significant difference between the displays for the user group (P = 0.13), ranging from 5.3 s (2 MP color business) to 5.9 s (3 MP Gray). There was, however, a reduction in time over the study that was significant (P G G G 0.001) for all users; the group average decreased from 6.5 to 4.7 s per image. Physical measurements of the resolution, contrast, and noise properties of the displays were acquired. Most notably, the noise of the displays varied by 3.5Â Â Â Â between the lowest and highest noise displays. Differences in display noise were indicative of observer performance. However, the large difference in the magnitude of the noise was not predictive of the small difference (3%) in the observer sensitivity for various displays. This is likely because detection of interstitial lung disease is limited by B B B B Banatomical noise^rather than display or x-ray image noise.