Narrow energy band X-rays via mosaic crystal for mammography application

Monochromatic X-ray beams are desirable in various fields of diagnostic radiology. We are investigating an imaging system based on a narrow energy band X-ray source for mammography application. The narrow energy band is obtained by making use of a mosaic crystal that reflects X-rays from a conventional X-ray tube via Bragg diffraction. In this paper the characteristics of the system in terms of energy resolution and fluence rate are reported. Small field (1.1 × 3.0 cm2) radiographs of Plexiglas phantoms with a thickness up to 3.6 cm have been obtained with 18, 20 and 22 keV quasi-monochromatic beams. The field size is limited by the crystal size along one dimension and by the desired energy spread along the other one. A digital imaging system has been used to correct for non-uniformity of the X-ray beam.