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

Yoshimura, Kumiko; Shimamoto, Kazuhiro; Ikeda, Mitsuru; Ichikawa, Katsuhiro; Naganawa, Shinji

doi:10.1016/j.ejmp.2010.06.001

« Previous Next »Physica Medica: European Journal of Medical Physics
Volume 27, Issue 2 , Pages 109-116, April 2011

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

Kumiko Yoshimura
- Department of Radiological Sciences, Graduate School of Medicine, Nagoya University, 1-20 Daiko-Minami 1-chome, Higashi-ku, Nagoya, Aichi 461-8673, Japan
- Corresponding author. Tel.: +81 52 719 1524; fax: +81 52 719 1506.
Kazuhiro Shimamoto
- Department of Radiological Sciences, Graduate School of Medicine, Nagoya University, 1-20 Daiko-Minami 1-chome, Higashi-ku, Nagoya, Aichi 461-8673, Japan
Mitsuru Ikeda
- Department of Radiological Sciences, Graduate School of Medicine, Nagoya University, 1-20 Daiko-Minami 1-chome, Higashi-ku, Nagoya, Aichi 461-8673, Japan
Katsuhiro Ichikawa
- Department of Health Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan
Shinji Naganawa
- Department of Radiology, Graduate School of Medicine, Nagoya University, 65 Tsurumai, Showa-ku, Nagoya, Aichi 466-8550, Japan

Received 20 November 2009; received in revised form 20 April 2010; accepted 2 June 2010. published online 30 June 2010.

Abstract

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.

Keywords: Liquid crystal displays (LCD), Brain CT, Image contrast, Grayscale calibration