Sensitometry of intensifying screen-film system for detection of yearly change of imaging quality factors

Systematic sensitometry of 20 green- and 25 blue-intensifying screens made in early 1980s and early 1990s was performed on their physical imaging qualities to evaluate their yearly change. Sensitometry was done with Toshiba KXO-1000 X-ray generator (Tube: Toshiba DRX-431HD, 80 kV, 20 mm-thick Al-filter), characteristic curve examination with KXO-15 (Tube: DRX-1603B, 80 kV, 0.5 mm Cu+4.0 mm Al), determination of modulation transfer function with KXO-15 (Tube: DRX-1303B, 80 kV, 2.0 mm Al), and Wiener spectrometry with Hitachi DH-158 (Tube: Hitachi UH-6GC-108DL, 80 kV, 20 mmAl). Reference screen was that reported by US Bureau of Radiological Health (1982) and Center for Devices and Radiological Health (196) and was obtained from Chicago University. There were products without yearly change, with increased sensitivity with unchanged resolution and noise level, with improved resolution, or with improved sensitivity. (K.H.)