The Acceptance Testing of 5 Mega Pixels Primary Electronic Display Devices and the Study of Quality Control Guideline Suitable for Domestic Circumstance / 의학물리

ABSTRACT

In June 2005, Yonsei University Medical Center, Severance Hospital upgraded a full-PACS system by adding twenty (5 mega pixels) Totoku ME511L flat panel LCD display devices for diagnostic interpretation purposes. Here we report upon the quantitative (or visual) acceptance testing of the twenty Totoku ME511L display devices for reflection, luminance response, luminance spatial dependency, resolution, noise, veiling glare, and display chromaticity based on AAPM TG 18 report. The tools used in the tests included a telescopic photometer, which was used as a colorimeter, illuminance meter, light sources for reflection assessment, light-blocking devices, and digital TG18 test patterns. For selected 8 flat panel displays, mean diffuse reflection coefficient (Rd) was 0.019+/-0.02 sr(-1). In the luminance response test, luminance ratio (LR), maximum luminance difference (Lmax), and deviation of contrast response were 550+/-100, 2.0+/-1.9%, and 5.8+/-1.8%, respectively. In the luminance uniformity test, maximum luminance deviation was 14.3+/-5.5% for the 10% luminance of the TG18-UNL10 test pattern. In the resolution test with luminance measurement method, percent luminance (Delta L) at the center was 0.94+/-0.64%. In all cases of noise testing, rectangular target in every square in the three quadrants was visible and all 15 targets except the smallest one in the every corner pattern and the center pattern. The glare ratio (GR) was 12,346+/-1,995. The color uniformity, (u',v'), was 0.0025+/-0.0008. Also, the research results of quality control guideline of primary disply devices suitable for domestic circumstance are presented. All test results are in-line with the criteria recommended by AAPM TG18 report and are thus fully acceptable for diagnostic image interpretation. As a result, the acceptance testing schedule described provides not only an acceptance standard but also guidelines for quality control, optimized viewing conditions, and a means for determining the upgrading time of LCD display devices for diagnostic interpretation.