Psychophysical analysis of monitor display functions affecting observer diagnostic performance of CT image on liquid crystal display monitors

Yamaguchi, Michihiro; Fujita, Hideki; Asai, Yoshiyuki; Uemura, Masanobu; Ookura, Y.; Matsumoto, Masao; Johkoh, Takeshi

doi:10.1007/s00330-005-2880-0

Cited by 6 publications

(4 citation statements)

References 18 publications

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“…During the 1960s, Kanamori 3,4 proposed the psychophysical gradient δ, corresponding to visually recognized contrast, which can be used for inspection of perceptual linearization. In previous articles, [5][6][7] we confirmed the usefulness of applying δ to liquid crystal display (LCD) monitors. The objectives of the present work are (1) to compare, using ROC analysis, the suitability of the GSDF and CIE curves as calibration tools for clinical images and (2) to explain the relation between tumor detectability and visually recognized contrast using psychophysical analysis.…”

Section: Introductionsupporting

confidence: 55%

Psychophysical evaluation of calibration curve for diagnostic LCD monitor

et al. 2006

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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.

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Section: Introductionsupporting

confidence: 55%

Psychophysical evaluation of calibration curve for diagnostic LCD monitor

et al. 2006

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“…We must investigate the optimal viewing size for detecting n-GGOs from the viewpoint of the human visual system in the future. Third, other factors were not evaluated such as the display luminance and display function, which also influence observer performance [20][21][22][23]; however, GSDF is recommended as a standard display function for soft-copy diagnosis [24]. Fourth, we did not use a low-dose protocol for lung cancer CT screening.…”

Section: Discussionmentioning

confidence: 98%

Investigation of optimal viewing size for detecting nodular ground-glass opacity on high-resolution computed tomography with cine-mode display

Yamaguchi

Bessho

Inoue

et al. 2010

Radiol Phys Technol

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We evaluated the effect of the displayed image sizes on observers' ability to detect nodular ground-glass opacity (n-GGO) on CT and investigated the optimal viewing size for soft-copy reading at CT screening for lung cancer. A total of 46 patients' high-resolution computed tomography (HRCT) images (22 patients with one GGO; 24 without GGO) were displayed on a monochromatic liquid crystal display monitor at a resolution of 1,200 × 1,600. HRCT was presented on the screen with cine-mode display. We compared two viewing sizes (original size, i.e., the image displayed with a zoom factor of 1 in which each pixel value in the image is displayed as one pixel on the display: 13 cm × 13 cm; fit size, i.e., by zooming the captured image until it occupies the entire screen: 30 cm × 30 cm) in terms of radiologists' performance for detecting n-GGO on HRCT and the viewing times required for soft-copy reading decisions. Observer performance was analyzed in terms of the receiver operating characteristic (ROC) curve. A statistically significant improvement was found with the original size in the average area-under-the-ROC curve values for the accuracy of diagnosis and the viewing times compared to the fit size (P < 0.05). The original size with cine-mode display leads to increased lung GGO detection at CT screening for lung cancer, and the reduced time spent performing the diagnosis offers cost savings.

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“…Yamaguchi et al [11] reported that the display function combining gamma 2.2 and GSDF was ideal for the interpretation of brain CT images. In our study, the gray level of brain parenchyma was shown to be within a range where the image contrast on gamma 2.2 was higher than the one on GSDF, which suggested that the image contrast of a brain CT on a general-type LCD or notebook PC was better than one on a medical-grade LCD.…”

Section: Discussionmentioning

confidence: 99%