Thick clear crystal photostimulable phosphor plate for x-ray imaging

Abstract

A radiation imaging apparatus includes a photostimulable phosphor plate, an x-ray source, a red or infrared laser, and an array of photomultiplier tubes. The x-ray source propagates x-rays toward the plate, which is incident on the plate at a first incidence angle. The x-rays interact with the plate to form a latent image therein. The laser propagates laser radiation toward the plate which is incident on the plate at a second incidence angle. According to the invention, the second incidence angle is equivalent to the first incidence angle at substantially all points on the plate. Based on the interaction of the laser radiation with the latent image in the plate, the plate emits visible image radiation. Thus, the x-ray radiation, which forms the image in the plate, follows the same path within the plate as does the laser radiation. By ensuring that the laser radiation follows the same path through the plate as the x-ray radiation, the invention achieves high spatial resolution in the image detected by the laser. The array of photomultiplier tubes receives the image radiation emitted by the plate and generates an electrical image signal based thereon. Based on this electrical image signal, the image formed in the plate may be displayed on a display device or printed on a printer. The device may also include an aspheric lens attached to the plate that refracts the laser radiation so that it enters the plate at the same incidence angle as the x-ray radiation. Using this lens, the x-ray and laser radiation may enter the plate from opposite sides of the plate and still follow the same path through the plate. Preferably, the photostimulable phosphor plate is formed of barium fluoroiodide—BaFI(Eu).