Computed tomography with image intensifier: potential use for nondestructive testing and imaging of small objects

An image intensifier based computed tomography scanner and a tube source of X-rays are used for nondestructive evaluation, imaging of small objects fo r archaeological studies and conservation of works of art and micro analysi s of soft materials. It consists of a charge coupled device (CCD) camera an d an acquisition board. The CCD camera and the acquisition board allow imag e processing, filtration and restoration. The object is irradiated by an X- ray tube with a conical collimator and rotated on 180 degrees. Projections are obtained at various angles as cross sectional image slices. A reconstru ction program written in PASCAL is able to give the reconstruction matrix o f the linear attenuation coefficients, simulates the matrix and related tom ography, The flux emitted by the tube is filtered using the appropriate fil ters at the chosen optimum energy and reasonable monochromacy is achieved f or all the images. Although X-ray imaging is a potential tool for strongly attenuating materials, the images of weakly attenuating materials provide n ew information to know about their structure and also the foreign body for the image reconstruction at an optimum value, The image of the plastic mate rial which contains the internal defect is studied thoroughly at the optimu m value in order to image the small objects for nondestructive testing, arc haeological studies and conservation of works of art, The images are analys ed using the profile data showing the internal defect of the object to obta in information at the optimum value. At the optimum value and with the aid of the tomographic image, the size and location of the defect could be asce rtained. (C) 2000 Elsevier Science Ltd, All rights reserved.