Patent ID: 6042986
Filing Date: 2000-03-28
Classification: G03C,Y10S

Abstract:
A process of confirming the targeting of a beam of X-radiation of from 4 to 25 MVp comprised of(a) directing the X-radiation at a subject containing features that are identifiable by differing levels of X-radiation absorption and creating a first latent image of X-radiation penetrating the subject in a radiographic element,(b) placing a shield containing a portal between the subject and the source of X-radiation, directing X-radiation at the subject through the portal, and creating a second latent image superimposed on the first latent image in the radiographic element,(c) employing a processor to convert the latent images to viewable silver images from. which intended targeting of the X-radiation passing through the portal in relation to the identifiable features of the subject is realized, the processor relying on attenuation of an infrared beam of a wavelength from 850 to 1100 nm by the radiographic element for activation,WHEREIN(d) the radiographic element is comprised of a transparent film support having first and second major surfaces and, coated on each of the major surfaces, processing solution permeable hydrophilic colloid layers, at least one of said layers on each major surface including a light-sensitized silver halide grain population capable of providing a contrast in the range of from 4 to 8 and containing greater than 50 mole percent chloride and less than 3 mole percent iodide, based on silver, the total grain population being coated at a silver coverage of less than 30 mgidm.sup.2 and having a mean equivalent circular diameter of less than 0.6 .mu.m,(e) during steps (a) and (b), total X-radiation exposure is limited to 10 seconds or less, at least one metal screen capable of emitting electrons when exposed to the X-radiation beam is interposed between the X-radiation beam and the radiographic element and at least one fluorescent intensifying screen is positioned to receive electrons from the metal screen and emit light to expose the radiographic element,(f) when introduced into the processor in step (c), the radiographic element of (d) further contains, in at least one of the hydrophilic colloid layers, high bromide silver halide particles containing less than 3 mole percent iodide, based of silver, and having an index of refraction in the wavelength range of from 850 to 1100 nm that differs from that of the hydrophilic colloid in said one of the hydrophilic colloid layers by at least 0.2 to create a specular density capable of attenuating the infrared beam and activating the processor, and(g) during step (c), the silver halide grain population is developed imagewise to produce the viewable silver images and undeveloped silver halide grains and the particles are removed from the radiographic element.