Luminance Response Research Articles

WE-D-204-03: A Six-Year Longitudinal Evaluation of the DICOM GSDF Conformance Stability of LCD Monitors

Purpose: The calibration of monitors in radiology is critical to ensure a standardized reading environment. If left unchecked, monitors initially calibrated to follow the DICOM Grayscale Standard Display Function (GSDF) can fall out of calibration. This work presents a quantitative evaluation of the stability of a cohort of monitors with similar deployment times and clinical utilization. Methods: Fifty-four liquid crystal display (LCD) monitors (NEC L200ME) were deployed for clinical use in 2009. At that time, a subset of eight of these monitors were used to generate a look-up table (LUT) using the open-source software pacsDisplay. The software was used to load the LUT to the graphics card of the computer in order to make the monitors compliant with the GSDF. The luminance response of the monitors was evaluated twice over six years, once in 2011 and again in 2015. Results: As expected, the maximum luminance of the monitors decreased over time, with an average reduction from 2009 of 35% in 2011, and 53% in 2015. The luminance ratio (maximum luminance divided by the minimum) also decreased, with the all of the decrease occurring in the first two years (average 20%). There was an overall increase in relative error compared with the DICOM GSDF from measurement to measurement, indicating that deviation from the GSDF increases with monitor luminance reduction. Along with changes in luminance, several other issues were identified during the testing, including non-uniformities, bad pixels, and missing calibration software. Conclusion: From the initial installation of these monitors, most of the degradation occurred during the first two years, highlighting the importance of routine clinical testing of displays. Following such quality assurance, displays could be either re-calibrated or replaced depending on different thresholds. In addition, other issues not related to luminance could be identified and corrected.

A neurophysiologically‐based analysis of lightness and brightness perception

AbstractPsychophysical, achromatic luminance threshold, and scaling data have been analyzed and found to follow from nonlinear, hyperbolic responses of retinal cones. For short (0.1 s) stimulus duration, a stable state of visual adaptation could explain the threshold response, but for longer durations a change of adaptation had to be considered. This resulted in a contrast sensitivity that increased when the stimulus duration increased and became constant for higher test field luminances. Threshold and scaling data can thus be traced back to cone‐specific responses over a much larger range of stimulus intensity than has been anticipated earlier. The experimental results, including those for lightness and brightness scaling, have been compared with the CIELAB and the CIEDE2000 color formulas. The idea of combining cone responses with adaptive changes to describe luminance responses resulted in a common cone‐based response formula for describing both luminance thresholds and scaling data. Adaptive changes explain the reason why both Weber–Fechner and Stevens’ laws are valid. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 339–351, 2016

An Assessment on Glare from Daylight through Various Designs of Shading Devices in Hot Humid Climate, Case Study in Kuala Lumpur, Malaysia

Glare is one of the main problems that cause daylight to be visually undesirable in a hot humid country such as Malaysia. However, the design of modern buildings in Malaysia applies large glass windows and some partially covered with various design of shading devices, which are merely for aesthetic reason. Having sun shading devices have not solved the glare problems instead create either dark interiors or force for interior blinds and use of electrical lighting. Thus, this paper aims to investigate the glare performance under daylight through most common types of shading devices used in Kuala Lumpur, Malaysia. The four most common shading devices are: vertical, horizontal, egg-crate and geometrical pattern. The experiment covers the luminance, illuminance level and subjective responses of the occupants. The result indicates that under the vertical shading devices has spotted the highest glare values, in contrast subjective response indicate that the vertical shading devices provide most comfortable environment.

Smoking and early infliximab response in Crohn’s disease: a meta-analysis.

Infliximab is used to treat moderate to severe Crohn’s disease (CD), but its efficacy varies. Although cigarette smoking worsens CD, its impact on the infliximab response is unknown. We conducted a systematic review and meta-analysis of clinical trials to determine the effect of smoking on the induction response to infliximab. A systematic search was performed of MEDLINE, EMBASE, CINAHL, the Cochrane central register of controlled trials, the Cochrane IBD Group Specialized Trials Register for publications, and abstracts from major conferences from January 1996 to December 2010. Random effects meta-analysis using the Mantel–Haenszel method was conducted. Heterogeneity across studies was assessed using the Q statistic, the I2 statistic, and τ2. We identified 12 articles; four were excluded due to use of non-validated scoring systems.The remaining eight included a total of 1658 patients, with 649 active smokers. Luminal response was assessed by the Crohn’s Disease Activity Index in four studies (three of which included fistula response) and the Harvey–Bradshaw index in two (both including fistula response), and two studies examined only the fistula response. The relative risk for response to infliximab among smokers was 0.99 (95% CI 0.88–1.11) (τ2 = 0.0143). Analyses of the five studies examining both inflammatory and fistulizing CD were similar to the analysis of all eight studies. The pooled relative risk was 0.92 (95% CI 0.80–1.06) (τ2 = 0.0154). Though smoking worsens CD, this meta-analysis does not show a negative effect of smoking on initial response to infliximab. This must be viewed in the proper context, as long-term maintenance of response may yet be influenced by smoking status.

Technical and radiological image quality comparison of different liquid crystal displays for radiology.

BackgroundTo inform cost-effective decisions in purchasing new medical liquid crystal displays, we compared the image quality in displays made by three manufacturers.MethodsWe recruited 19 radiologists and residents to compare the image quality of four liquid crystal displays, including 3-megapixel Barco®, Eizo®, and NEC® displays and a 6-megapixel Barco display. The evaluators were blinded to the manufacturers’ names. Technical assessments were based on acceptance criteria and test patterns proposed by the American Association of Physicists in Medicine. Radiological assessments were performed on images from the American Association of Physicists in Medicine Task Group 18. They included X-ray images of the thorax, knee, and breast, a computed tomographic image of the thorax, and a magnetic resonance image of the brain. Image quality was scored on an analog scale (range 0–10). Statistical analysis was performed with repeated-measures analysis of variance.ResultsThe Barco 3-megapixel display passed all acceptance criteria. The Eizo and NEC displays passed the acceptance criteria, except for the darkest pixel value in the grayscale display function. The Barco 6-megapixel display failed criteria for the maximum luminance response and the veiling glare. Mean radiological assessment scores were 7.8±1.1 (Barco 3-megapixel), 7.8±1.2 (Eizo), 8.1±1.0 (NEC), and 8.1±1.0 (Barco 6-megapixel). No significant differences were found between displays.ConclusionAccording to the tested criteria, all the displays had comparable image quality; however, there was a three-fold difference in price between the most and least expensive displays.

Determining appropriate ambient lighting levels in Radiology reporting rooms

Determining appropriate ambient lighting levels in Radiology reporting rooms

Luminance and colour variant pupil perimetry in glaucoma.

This study investigated the diagnostic utility for glaucoma of multifocal pupillographic objective perimetry stimuli targeting different components of the pupillary response: cortically derived colour responses and subcortical luminance responses. Observational cross-sectional study undertaken at the Australian National University. Thirty-five eyes of 24 glaucoma subjects and 46 eyes of 23 normal subjects. Subjects were tested with three multifocal pupillographic objective perimetry stimulus variants. The luminance-only variant (YYbal) utilized yellow stimuli on a yellow background; mixed colour and luminance protocols utilized green stimuli on a red background (RGbal, RG). Stimuli of 33 ms duration were presented at mean intervals of 4 s/region. Pupil constriction amplitude and time to peak. Area under the receiver operating characteristic curve was the main measure of sensitivity and specificity for glaucoma. Colour and luminance protocols were more accurate at differentiating glaucoma subjects from normal subjects than the luminance-only protocol, and produced the largest reductions in amplitudes. This type of protocol also produced the highest overall sensitivity and specificity for glaucoma (receiver operating characteristic % area under the curve: severe, 100%; moderate, 94.4%; mild, 71.0%). Pattern deviations tended to produce higher area under the receiver operating characteristic curves in eyes classified as mild. Significant differences in the means of the six worst amplitude deviations were observed between normal and severe glaucoma subjects only. Stimuli targeting both cortical pupillary colour response and subcortical pupillary luminance response components produced higher diagnostic accuracy than stimuli targeting subcortical pupillary luminance responses alone. Inclusion of constriction latencies further improved accuracy.

30P - Prognostic Role of Luminal Subtype in Metastatic Breast Cancer Patients Treated with Fulvestrant in the Confirm Trial

Introduction: Luminal A (LumA) breast cancer (BC) patients benefit more from adjuvant hormonal therapy compared to luminal B (LumB), but interaction between luminal status and response to Fulvestrant (Ful) in the metastatic setting has never been explored. We hypothesize that the luminal subtype might be prognostic in MBC patients treated with Ful.

Luminal ATP: the missing link between intestinal alkaline phosphatase, the gut microbiota, and inflammation?

gut dysbiosis is a common feature to many inflammatory diseases but the cause-and-effect relationships between the gut microbiota and host inflammation are poorly understood. For metabolic disorders and obesity, however, bacterial lipopolysaccharide (LPS), an emblematic member of pathogen-associated

Neuronal nonlinearity explains greater visual spatial resolution for darks than lights

Astronomers and physicists noticed centuries ago that visual spatial resolution is higher for dark than light stimuli, but the neuronal mechanisms for this perceptual asymmetry remain unknown. Here we demonstrate that the asymmetry is caused by a neuronal nonlinearity in the early visual pathway. We show that neurons driven by darks (OFF neurons) increase their responses roughly linearly with luminance decrements, independent of the background luminance. However, neurons driven by lights (ON neurons) saturate their responses with small increases in luminance and need bright backgrounds to approach the linearity of OFF neurons. We show that, as a consequence of this difference in linearity, receptive fields are larger in ON than OFF thalamic neurons, and cortical neurons are more strongly driven by darks than lights at low spatial frequencies. This ON/OFF asymmetry in linearity could be demonstrated in the visual cortex of cats, monkeys, and humans and in the cat visual thalamus. Furthermore, in the cat visual thalamus, we show that the neuronal nonlinearity is present at the ON receptive field center of ON-center neurons and ON receptive field surround of OFF-center neurons, suggesting an origin at the level of the photoreceptor. These results demonstrate a fundamental difference in visual processing between ON and OFF channels and reveal a competitive advantage for OFF neurons over ON neurons at low spatial frequencies, which could be important during cortical development when retinal images are blurred by immature optics in infant eyes.

Digoxin-Induced Reversible Dysfunction of the Cone Photoreceptors in Monkeys

To investigate functional alteration of the retina induced by digoxin in monkeys. Digoxin was intravenously administered to cynomolgus monkeys and standard full-field electroretinograms (ERGs) were serially recorded. In other digoxin-treated monkeys, the rod and cone a-waves to high-intensity flashes were obtained and analyzed by the a-wave fitting model (a-wave analysis). The following responses were also recorded: dark- and light-adapted responses to flashes of different intensities (dark- and light-adapted luminance responses), photopic ERG elicited by long-duration stimulus (ON-OFF response), and the photopic negative response (PhNR). Delayed b-wave was observed in all responses of the standard full-field ERGs; amplitude of the b-wave was increased in the rod response, but was decreased in the single-flash cone response and the 30-Hz flicker. These changes recovered gradually after elimination of digoxin from the blood. Digoxin enhanced and delayed the b-wave in the dark-adapted luminance-response analysis regardless of stimulus intensity. In the light-adapted luminance-response analysis, digoxin attenuated the a- and b-waves only at high and middle stimulus intensity, respectively. The a-wave analysis revealed selective decrease in the maximum response parameter (Rmax) in the cone a-wave. Both the b- and d-waves of the ON-OFF response were delayed. The selectively reduced Rmax in the cone a-wave indicated dysfunction of the cone photoreceptors in digoxin-treated monkeys. Meanwhile, the enhanced and delayed rod response suggested alteration of retinal components other than the cone photoreceptors. These results may contribute to the understanding of digoxin-induced visual disturbances in humans. It is suggested that the cone function is markedly, but not exclusively, affected in the retina of such patients.

Incremental and decremental L- and M-cone-driven ERG responses: I Square-wave pulse stimulation

Electroretinograms (ERGs) elicited by transient, square-wave L- and M-cone isolating stimuli were recorded from human trichromatic (n=19) and dichromatic (n=4) observers. The stimuli were generated on a four primary LED stimulator and were equated in terms of cone modulation (cone contrast=0.11) and retinal illuminance (12,000 trolands). L- and M-cone isolated ERGs had waveforms similar to those observed for luminance responses. However, M-cone ERGs exhibited a phase reversal in their responses to onset and offset stimuli relative to the L-cone responses. This on-off response reversal was observed in trichromats but not dichromats. Simultaneous counterphase and inphase combinations of L- and M-cone isolating stimuli generated responses that reflected chromatic and luminance processing, respectively. We conclude that L- and M-cone specific ERGs provide a measure of how photoreceptors contribute to postreceptoral mechanisms.

Preparation of Layered Inorganic/Luminous Dyes Nano-Hybrid Materials with Higher Luminescence and its Luminous Response for Environmental Variation

Preparation of Layered Inorganic/Luminous Dyes Nano-Hybrid Materials with Higher Luminescence and its Luminous Response for Environmental Variation

Image Quality Characteristics of Handheld Display Devices for Medical Imaging

Handheld devices such as mobile phones and tablet computers have become widespread with thousands of available software applications. Recently, handhelds are being proposed as part of medical imaging solutions, especially in emergency medicine, where immediate consultation is required. However, handheld devices differ significantly from medical workstation displays in terms of display characteristics. Moreover, the characteristics vary significantly among device types. We investigate the image quality characteristics of various handheld devices with respect to luminance response, spatial resolution, spatial noise, and reflectance. We show that the luminance characteristics of the handheld displays are different from those of workstation displays complying with grayscale standard target response suggesting that luminance calibration might be needed. Our results also demonstrate that the spatial characteristics of handhelds can surpass those of medical workstation displays particularly for recent generation devices. While a 5 mega-pixel monochrome workstation display has horizontal and vertical modulation transfer factors of 0.52 and 0.47 at the Nyquist frequency, the handheld displays released after 2011 can have values higher than 0.63 at the respective Nyquist frequencies. The noise power spectra for workstation displays are higher than 1.2×10−5 mm2 at 1 mm−1, while handheld displays have values lower than 3.7×10−6 mm2. Reflectance measurements on some of the handheld displays are consistent with measurements for workstation displays with, in some cases, low specular and diffuse reflectance coefficients. The variability of the characterization results among devices due to the different technological features indicates that image quality varies greatly among handheld display devices.

Constancy of built‐in luminance meter measurements in diagnostic displays

Liquid crystal displays used to interpret medical images are often equipped with built-in luminance meters to evaluate luminance response and Grayscale Standard Display Function conformance. This work evaluates agreement between luminance reported by the built-in meters and external measurements. The white level luminance was measured using a built-in meter and an external meter for 93 primary review workstations (Models MFGD 3420 and MDCG 3120-CB) with between 117 and 49,336 backlight hours (BLH). Measured luminance values were compared via t-test for displays with less than 25,000 BLH and those with more than 25,000 BLH. Bias between meters was also evaluated. Changes in luminance uniformity with increasing backlight hours were explored by determining the maximum luminance deviation (MLD) for subsets of these displays with less than 800 BLH and greater than 35,000 BLH. The mean difference between built-in and external luminance measurements was 5.84% and 38.92% for displays with less than 25,000 and greater than 25,000 BLH, respectively, with a statistically significant difference in the means (p < 0.001). For displays with low BLH, a statistically significant bias was observed (p < 0.001) between built-in and external measurements. A high degree of correlation was observed between measurements made with two separate external meters (r = 0.999). The mean MLD was 9.5% and 11.2% for MDCG 3120-CB displays with less than 800 and greater than 35,000 BLH, respectively. The difference in the mean values was not statistically significant (p < 0.001). Disagreement between the white level luminance measured using the built-in and external meter increased with BLH. Consequently, reliance on values reported by the built-in luminance meter may result in a reduction in image contrast with time. Recommendations have been proposed regarding luminance response testing and corrective action for failing displays.

GlyT1 inhibitor reduces oscillatory potentials of the electroretinogram in rats

Context: Selective inhibitors of glycine transporter type 1 (GlyT1) increase synaptic glycine concentrations and are being developed to treat cognitive and negative symptoms of schizophrenia. However, increases in systemic glycine levels have been associated with visual disturbances and electroretinogram (ERG) alternations.Objective: To determine whether the selective GlyT1 inhibitor PF-03463275 causes changes in ERG responses in albino rats.Materials and methods: Male Sprague-Dawley rats were administered PF-03463275 subcutaneously at 1, 3 and 10 mg/kg 1 h prior to ERG acquisition. Scotopic and photopic luminance responses, photopic adaptometry and flicker responses were measured. Plasma and vitreous samples were obtained at necropsy for determination of PF-03463275 concentrations.Results: A dose-dependent reduction (up to ∼70%) in the amplitude of the scotopic ERG oscillatory potentials (OPs) was observed following PF-03463275 administration. The amplitude of the OPs was also negatively correlated to the concentration of PF-03463275 in the vitreous humor (r = −0.64, p < 0.0001). With the exception of a small increase in scotopic ERG a-wave amplitude and latency no effects were observed on other ERG parameters tested.Conclusions: We conclude that inhibition of the GlyT1 transporter in the retina causes ERG changes which may underlie recent reports of visual disturbance with GlyT1 inhibitors in clinical trials.

Abstract A053: ErbB3 downregulation enhances luminal breast tumor response to antiestrogens

Abstract HER3/ErbB3 is required in luminal mammary epithelial cells (MECs). Given that breast cancer phenotypes may reflect biological traits of the MECs from which they originate, we tested the hypothesis that HER3/ErbB3 drives luminal breast cancer growth. We found higher ERBB3 expression and frequent ERBB3 gene copy gains in clinical Luminal A/B breast cancers over other molecular subtypes. ErbB3 increased growth of luminal breast cancer cells, while ErbB3 targeting using U3-1287, a fully-human monoclonal anti-ErbB3 antibody, decreased three-dimensional colony growth, increased apoptosis, and decreased tumor growth in vivo. In response to the anti-endocrine fulvestrant, ErbB3 expression increased in clinical breast tumors, as did phosphatidylinositol 3-kinase (PI3K)/mTOR signaling. However, ErbB3 targeting with U3-1287 blocked compensatory PI3K/mTOR signaling in fulvestrant-treated tumor cells, transcriptional responses to fulvestrant, tumor cell survival and tumor growth. U3-1287 produced these effects in tumor cells with and without genetic PI3K pathway aberrations (PIK3CAH1047R, PIK3CAE545K, PTEN loss). Although fulvestrant increased phosphorylation of all ErbB family RTKs and insulin-like growth factor-1 receptor, phospho-RTK upregulation was not seen in tumors treated with U3-1287 and fulvestrant. Therefore, luminal breast cancer cells utilize ErbB3 for growth, survival, and to limit response to fulvestrant, thus defining a novel role for ErbB3 in breast cancer. Citation Format: Meghan M. Morrison, Jamie Stanford, Christian Young, David Vaught, Andrew Williams, michelle williams, Chuck M. Perou, Carlos L. Arteaga, Rebecca S. Cook. ErbB3 downregulation enhances luminal breast tumor response to antiestrogens. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr A053.

Adalimumab for Crohn’s disease after infliximab treatment failure

The tumor necrosis factor inhibitors infliximab and adalimumab are effective treatments for Crohn's disease (CD); however, some patients treated with infliximab experience a loss of efficacy. There is a lack of high-quality evidence available on whether adalimumab is an effective treatment for patients who have failed infliximab treatment. A systematic review was carried out to examine the efficacy and safety of adalimumab for the treatment of CD in patients who have failed infliximab treatment. PubMed, Google Scholar, and the Cochrane Library were searched using the terms 'adalimumab AND infliximab AND Crohn's'. Randomized-controlled trials and cohort studies were included if they involved patients treated with adalimumab after failing infliximab. Outcomes were response and remission rates, adverse event (AE) rate, and the rate of discontinuations because of AEs. Ten studies (one randomized-controlled trial and nine cohort studies) involving 1009 patients were included. Luminal disease remission rates ranged from 12 to 67% during induction and 29 to 72% during maintenance therapy. Fistulizing disease remission rates ranged from 5 to 50% during induction and 27 to 68% during maintenance therapy. Luminal disease response rates ranged from 29 to 83% during induction and 31 to 59% during maintenance therapy. Fistulizing disease response rates ranged from 15 to 44% during induction and 41 to 56% during maintenance therapy. The overall AE rate ranged from 13 to 69%. Most AEs were mild to moderate in severity. The rate of discontinuation because of AEs ranged from 0 to 14%. The findings reported in the current literature support adalimumab as an efficacious and safe treatment for CD in patients who have failed infliximab treatment.

Neuronal nonlinearity explains greater visual spatial resolution for dark than for light stimuli

Astronomers and physicists noticed centuries ago that visual spatial resolution is higher for dark than light stimuli [1,2], but the neuronal mechanisms for this perceptual asymmetry remain undetermined. We investigated the neuronal mechanisms of this difference in spatial resolution by recording single ON- and OFF-center cells in the visual thalamus (LGN) and multi-unit activity in the visual cortex (V1) of cats. We found that receptive fields of ON-center cells were larger than receptive fields of OFF-center cells in LGN (Figure 1A, B top; ON/OFF = 1.27, p < 0.01) and V1 (ON/OFF = 1.29, p < 0.001), when mapped on binary backgrounds (light targets on dark backgrounds and dark targets on light backgrounds). Surprisingly, when receptive fields were mapped on gray backgrounds, these differences disappeared in the LGN (Figure 1 A, B bottom; ON/OFF = 0.97, p = 0.3) and were slightly reversed in V1 (ON/OFF = 0.8, p = 0.004). Thus, the difference in spatial resolution between ON and OFF neurons is not constant and changes dynamically with the background luminance, as is also the case for the difference in human spatial resolution for darks and lights. Figure 1 Functional asymmetries between ON and OFF channels. ON receptive fields are larger than OFF receptive fields (A, B; left) on dark but not gray backgrounds. Luminance response functions are more linear in ON (A; right) than OFF (B; right) channels in the ... We hypothesized that a nonlinear encoding of luminance increments and decrements could explain these differences. We found that OFF cells in LGN increase their responses roughly linearly (Figure ​(Figure1B,1B, right) with luminance decrements, independent of the background luminance (luminance half-saturation = L50; LGN OFF L50 light/gray = 0.99, p = 0.9; V1 OFF L50 light/gray = 1.03, p = 0.2). In marked contrast, ON-center cells saturate their responses with small increases in luminance (Figure ​(Figure1A,1A, top-left) and require bright backgrounds to approach the linearity of the OFF-center cells (Figure ​(Figure1A,1A, bottom-left; LGN ON L50 dark/gray = 0.28, p < 0.001; V1 ON L50 dark/gray = 0.3, p < 0.001). Although the integration of lights becomes more linear as the luminance of the background increases, ON responses still saturate more than OFF responses on gray backgrounds (V1 L50 darks/lights = 1.25, p < 0.001). Similar differences in response linearity could be demonstrated in recordings from local field potentials in awake primates. Consistent with our hypothesis, we show that a simple computational model based on the ON-channel nonlinearity can explain the larger receptive fields and lower spatial resolution of ON cells, the differences in human spatial resolution between darks than lights, the differences in the size of ON and OFF dendritic fields from retinal ganglion cells and the recently demonstrated OFF dominance in visual cortex (larger number of OFF- than ON-dominated cortical neurons). These results demonstrate a fundamental difference in processing between ON and OFF channels, which could have major implications in visual perception and cortical development.

Performance evaluation of soft copy display systems according to AAPM TG18 protocol

The purpose of this study was to evaluate the display performance of the liquid crystal display monitors according to the American association of physicists in medicine task group 18 (AAPM TG18) protocol at prior and after new calibration. We measured minimum and maximum luminance, luminance ratio, luminance and contrast response, luminance angular and spatial dependency, resolution, veiling glare and chromaticity quantitatively for 33 medical displays. Display noise was evaluated only visually. The mean maximum luminance and luminance ratio were 386 and 273cdm(-2), respectively. The mean deviation of measured luminance and contrast response from expected response associated with the digital imaging and communications in medicine (DICOM) grayscale standard display function (GSDF) were 9.76 and 2.35% at prior calibration and 1.23 and 0.26% after recalibration, respectively. In luminance uniformity test the mean maximum luminance deviation was 16%. Luminance method was used in the spatial resolution test and the mean percent luminance difference was 12% at the center. The mean glare ratio was 1154. The average color uniformity parameter across the display area of each display device was 0.0093. Majority of the test results were in good agreement with the criteria recommended by AAPM TG18 report. Considerable improvement was observed in display luminance and contrast response with respect to expected response of DICOM GSDF after new calibration for some displays.