Medical-grade Display Research Articles

Thousand shades of gray – The role of imaging display in diagnosis of occult scaphoid fractures – A pilot study

IntroductionMost hospitals and clinics utilize commercial grade displays for viewing wrist radiographs. There is no evidence regarding the role of the imaging display used to evaluate the radiographs. The aim of this study was to compare the rates of scaphoid fracture diagnosis by commercial grade and medical grade displays. MethodsWrist radiographs of patients that had clinical signs of scaphoid fracture without findings on plain radiography (suspected scaphoid fractures) were retrospectively collected from ER department and interpreted for radiographic signs of fracture by four orthopedics seniors commercial grade and medical grade displays. The difference in fracture diagnosis rates were studied. Inter- and intra-observer variability were also studied. ResultsStudy population comprised of 175 high quality wrist radiographs were interpreted. Mean 48.25 (27%) scaphoid fractures were observed on commercial grade display compared to 66 (38.2%) on medical grade display (p = 0.076). The total inter-observer agreement could be defined as a moderate agreement (κ = 0.527, Accuracy = 0.77). Total agreement between all observers were observed in 86 (49.1%) cases compared to 89 (50.9%) cases when reviewing X-rays on commercial and medical displays, respectively. DiscussionThe scaphoid fracture detection rate on medical grade display was not statistically higher compared to non-medical grade displays, but we did find a tendency toward medical grade display. We found that in a substantial number of cases, our observers recognize signs of fracture that were initially evaluated as "suspected fracture" by the ER physicians. As a pilot study, we found evidence that support the need for a prospective study designed to compare the observations to a gold standard modality, such as MRI. We believe utilizing medical grade displays can increase the rate of diagnosis in cases of clinically suspected scaphoid fractures and better manage the clinical scenario of a suspected scaphoid fracture.

THE ROLE OF MONITORS IN THE VISUALIZATION AND ASSESSMENT OF THE INFERIOR ALVEOLAR CANAL

<h3>Background</h3> The inferior alveolar canal (IAC) is a familiar landmark for dentists. Clear visualization of the IAC and its relationship with developing or impacted mandibular third molars is especially important. Cone beam computed tomography (CBCT) has improved the ability for more accurate assessment of the IAC. <h3>Objective(s)</h3> The aim of this study was to determine if there is a difference in the ability to appropriately assess the third molar–IAC relationship between 3 different monitor types. <h3>Study Design</h3> In all,105 scans were randomized and evaluated by 2 calibrated and masked evaluators. Evaluation was performed on 3 different monitors: BARCO 3 MP medical-grade monitor, a prototype BARCO 2 MP monitor, and DELL ultrasharp monitor. Evaluations were completed in a dimly lit area. The luminance and ambient light were measured using a light meter. All 3 monitors were placed in same position for the evaluators and were adjusted such that the luminance was the same. The gold standard was established by 2 board-certified oral and maxillofacial radiologists and 1 oral and maxillofacial radiology resident, who assessed the data sets after the evaluation was completed and reached a consensus on the location of the IAC. <h3>Results</h3> The medical 3 MP monitor demonstrated the best interrater reliability with a percent agreement of 87% and a kappa value of 0.83. Accuracy was significantly greater with the medical-grade 3 MP compared with the consumer-grade display monitor, with an average increase in accuracy of 10.1%. A significantly higher accuracy (7.2%) was also obtained for the medical-grade 3 MP in comparison with the medical-grade 2 MP by 1 observer. <h3>Discussion/Conclusions</h3> This study found that the IAC can be well visualized and with a higher degree of accuracy on medical-grade display (3 MP) monitors compared with consumer-grade display monitors. The 2 MP prototype medical monitor showed a higher degree of accuracy compared with the consumer-grade monitor, although the differences were not statistically significant.

Comparing medical grade to commercial grade display in a radiation oncology environment

Electronic displays are used in every modern day medical clinic. They are used to view images that are needed to diagnose, treat, and follow-up on patients with a variety of conditions. The type of electronic display used varies from department to department. Currently, a type of displays called medical grade displays are used to evaluate and diagnose disease and conditions. Alternatively, commercial or entry level professional displays are used for almost everything else. In the field of radiation oncology medical images are often used to plan the treatment course for each patient. These images are always viewed using a commercial grade display. An experiment was completed to examine the role a medical grade display might have in a radiation oncology setting. Our study had certified dosimetrists and radiation oncologists view medical images on both a medical grade and commercial grade display and rank their preference on a scale. The observers assessed the images in different categories (Contrast, resolution, and sharpness) and also commented on their preference. Results indicated that the medical grade display performed better than the commercial grade display in every image quality category.

Different pixel pitch and maximum luminance of medical grade displays may result in different evaluations of digital radiography images.

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 0.165mm size pixels) and two maximum luminance values (250 and 500cd/m2) 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 tools was applied. The intra-radiologist and inter-observer reproducibility values were the highest for the 0.165mm size pixel at 500cd/m2 display, for both chest lesions and bone fractures evaluations. As regards chest lesions, observer performances were significantly greater with 0.165mm size pixel display at 500cd/m2 than with lower maximum luminance and/or larger pixel pitch displays. Concerning bone fractures, the performance obtained with 0.212mm size pixel display at 250cd/m2 was statistically lower than that obtained with 0.165mm sixe pixel display at 500cd/m2. Our results indicate that an increased maximum luminance level and a decreased pixel pitch of medical-grade display improve the accuracy of detecting both chest lesions and bone fractures.

A comparative contrast perception phantom image of brain CT study between high-grade and low-grade liquid crystal displays (LCDs) in electronic medical charts

The purpose of this study was to clarify whether non-medical-grade liquid crystal displays (LCDs) are acceptable for the soft-copy reading of brain CTs. Four kinds of color LCDs with different image quality levels were used: medical-grade LCD, low-grade general LCD calibrated with the grayscale display function (GSDF), low-grade general LCD calibrated with gamma 2.2 and a notebook personal computer display panel. In Osirix’s standard window setting for brain CTs, the average CT values of brain parenchyma in 100 cases were correlated with a grayscale level ranging from 71 to 91 in a 256-step grayscale. At these gray levels, the image contrast on the two low-grade LCDs calibrated with gamma 2.2 was higher than that on the medical-grade LCD. Eleven healthy volunteers participated in the contrast perception study, which used electronically generated target phantom images that simulated subtle abnormalities with a low or high attenuation difference in brain parenchyma. The three low-grade LCDs showed correct response rates and reaction times that were superior to those of the medical-grade display. The grayscale calibrations, GSDF or gamma 2.2, are likely to be more critical than the display grade, suggesting that the use of a low-grade LCD may be acceptable in the image contrast of brain CT.

Medical Grade vs Off-the-Shelf Color Displays: Influence on Observer Performance and Visual Search

The goal of this study was to compare diagnostic accuracy of radiologists viewing clinical images on a top-of-the-line medical-grade vs a top-of-the-line commercial off-the-shelf (COTS) color display with the luminance values set to simulate a display that had been in use for 1 year. A set of 50 digital radiography chest images was selected for use in the study, half containing a solitary pulmonary nodule and half nodule-free. The images were displayed twice to each of six observers, once on each display. Eye position was recorded on a subset of the images. Overall, there was a statistically significant difference (F = 4.1496, p = 0.0471) between the medical-grade color display and the COTS color display in terms of receiver operating characteristic area under the curve values, with the medical-grade display yielding higher diagnostic accuracy. Total viewing time did not differ significantly, but eye position data revealed differences, suggesting better search and decision-making efficiency with the medical-grade display. Medical-grade color displays at 1 year old yield better diagnostic and search efficiency than COTS color displays and thus are recommended for primary reading if color displays are to be used.