Original Jpn J Radiol Technol 1999 ;
Variation in Characteristic Curve Obtained by Change in Front-to-back Light-emission Ratio for Intensifying Screens Combined
with Double-coated Emulsion Film

SADAMITSU NISHIHARA, HIROMI NAGANO,1) KEN-ICHI YOSHIDA,1) AKIYOSHI OTSUKA,1) and ATSUSHI TAKIGAWA2)
Department of Radiology, Yamaguchi University Hospital
(Current address: Department of Radiological Sciences and Technology, Hiroshima Prefectural College of Health and Welfare)
1)Department of Radiology, Yamaguchi University Hospital
2)Department of Radiological Sciences and Technology, Hiroshima Prefectural College of Health and Welfare
Received Jan. 14, 1999; Revision accepted June 10, 1999; Code Nos. 521, 734, 921
Summary
Gradients of characteristic curves were investigated according to the change in front-to-back light-emission ratio (1/0.7 to 1/5.3) for intensifying screens combined with double-coated x-ray film with various crossover fractions. Average gradients were measured from the characteristic curves, and the crossover fraction for each film was also calculated. Results showed that the greater the front-to-back light-emission ratio of the screen, the lower the average gradient in all cases. A linear relationship was also found between average gradient and crossover fraction.
Key words: Intensifying screen, Characteristic curve, Average gradient, Crossover effect