[Fabrication of improved multi-slit equipment to obtain the input-output characteristics of computed radiography systems: correction of the heel effect, and application to high tube-voltage experiments].

Multi-slit equipment is a new experimental apparatus that can measure the input-output characteristics of a CR (computed radiography) system with limited influence of the fading effect. Kimoto et al. recently proposed a new type of multi-slit apparatus in which the multi-slit setup, the insertion region of the phosphor plate, and plate shielding are integrated to create a single handy-type item (an all-in-one type multi-slit apparatus). However, some problems remained unsolved. The aims of this study were to devise a setup for application to high tube voltage conditions, and to improve the all-in-one type multi-slit equipment so as to correct the heel effect. We examined the capabilities of our improved multi-slit equipment using diagnostic X-ray apparatus and found that it can obtain input-output characteristics with 5% accuracy for tube voltages of 40-140 kV and SID (source to image receptor distances) of 50-200 cm.

[Development of all-in-one multi-slit equipment for measurements of the input-output characteristic of a phosphor plate].

An input-output characteristic curve is an essential piece of information for analyzing medical images taken using a phosphor plate. In the multi-slit method, an actuator moves shields that have numerous slits during X-ray irradiation. Numerous data can be measured by one-time irradiation, so the fading effect is negligibly small. This method was recently proposed by Takegami et al., but their equipment consisted of large multiple compositions. The aim of this study was to fabricate a new handy type equipment that combines multiple productions into one small production. In this paper, we propose an idea for downscaling the size of the equipment, and report that the same input-output characteristic is obtained using our newly proposed method.