X-RAY TARGET DETERMINATION METHOD AND PORTAL RADIOGRAPHY ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide an X-ray target determination method which can be used for both positioning image forming and ascertaining image forming, by making a portal radiography element be composed of a film supporter with a first main plane and a second main plane to each of which the radiography element can respond. SOLUTION: A first radiography element and a second radiography element have respective first and second main planes, and a sufficiently precured treatment solution penetrable hydrophilic colloidal layer whose hydrophilic colloid is limited to lower than 45mg/dm<1> is applied so as to be easily treated in shorter than 45sec. At least the first layer of those layers can give a contrast of 4-8 and contains photosensitive silver halide particles containing iodide lower than 3mol% based on silver. The hydrophilic colloidal layer is made to allow at least 30% of crossover within a spectrum range of sensitivity which silver halide particles have.