Cathode ray tube quality control and acceptance testing program: Initial results for clinical PACS displays

The use of picture archiving and communication systems (PACS) and primary s oft-copy interpretation in radiology is growing rapidly. The authors presen t a cathode ray tube (CRT) acceptance test and quality control (QC) program developed over a 5-year period on the basis of experience with multiple PA CS and CRT vendors. The CRT QC procedures address monitor cleanliness and s etup, qualitative image quality, and quantitative luminance and color measu rements. Required materials include a photometer with luminance and color p robes and 100%-video, flat-field window and test images from the Society of Motion Picture Test Engineers (SMPTE). Luminance was found to change over time for all gray-scale CRTs examined, which necessitated quarterly recalib ration. The phosphor color of these monitors was also found to change, but changes were consistent and slow enough to warrant only annual measurements . Color measurements were found to be especially useful at initial setup an d for CRT replacement. Use of this program allowed standardization of absol ute luminance of individual CRTs, matching of phosphor color for multimonit or workstations, and systematic tracking of image artifacts. Implementation of a QC program is strongly recommended owing to the dynamic nature of CRT displays.