X-ray imaging system using diffractive x-ray optics for high definition low dosage three dimensional imaging of soft tissue

摘要

An X-ray imaging system utilizing diffractive X-ray examination is utilized which includes an interrogating X-ray path from a conventional broad band X-ray source having a standard emission point. X- rays from the X-ray source impinge on a toric monochronometer having monochromatic Bragg X-ray diffraction occurring resulting in monochromatic X-ray diffraction. X-rays exiting the slit aperture stop expand and form a scanning beam and pass through the specimen (usually soft tissue) being examined. In passing through the specimen, the X-rays receive image information by absorption, critical angle scattering, and, refraction, dependent upon the specimen, structure. The X-rays are then incident on a toric detection crystal where monochromatic Bragg X-ray diffraction again occurs leaving the image revealed by absorption, critical angle scattering, and, refraction which occurred in the specimen. The diffracted monochromatic X-rays with the specimen induced images are then directed to an X-ray detector for image processing. The preferred embodiment includes a mammography apparatus in which each mammary is swept and scanned by an oblong beam (in the order of 3×24 centimeters) with scan direction between nipple and chest. Due to beam expansion from the slit aperture stop to the toric detection crystal, mammary tissue at varied elevations from the slit aperture stop provides differing relative motion for mammary tissue at each elevation. Image processing actually segregates the soft tissue images by imaging planes taken normal to the mean path of the expanding beam. To enable construction of virtually any required diffracting surface, a technique of segmenting and bending diffracting crystals is disclosed.