医用液晶ディスプレイを用いたX線画像観察による眼の疲労度の客観的な評価

摘要

平成20年度の診療報酬改定では，「電子画像管理rn加算」が新設，平成22年度からは「デジタル映像化rn処理加算」が廃止され，急速にフイルムレス化が進んrnでいる．電子的な医用画像表示装置にはおもに液晶rnディスプレイ（liquid－crystal display，LCD）が使用さrnれている．%The aim of this study was to evaluate visual fatigue objectively by measuring accommodation time and critical fusion frequency (CFF) before and after reading posteroanterior chest radiographs displayed on medical-grade liquid-crystal displays (LCDs) under different monitor conditions. A color LCD (500, 170 cd/ m~2) and a monochrome LCD (500 cd/m~2) were used in this study. Six observers independently kept reading the radiographs for two hours to understand various lung nodules in the "Fatigue Session". Objective visual fatigue was measured by using the accommodation device and the CFF meter before and after the Fatigue Session. The ambient lighting of the laboratory was set at 35 lux. Both the accommodation time and the CFF between before and after the Fatigue Session indicated statistically significant differences (p<0.05). Our results on accommodation time and CFF before and after reading the radiographs on medical-grade LCDs indicated that visual fatigue could be evaluated objectively.