Assessment of the Capacity of the ProGraf-7000 X-Ray Apparatus for Tomosynthesis

Slices of density of an object reconstructed using tomosynthesis from a limited-angle projection are attractive as a medical diagnostic tool due to high resolution of such slices and much smaller, compared to full-angle CT, required radiation dose and cost of instrument manufacture. However, the incompleteness of the projection sets leads to reconstruction artifacts that look like smeared (or repeated) and faded images of actual objects lying in other slices and requires reconstruction methods tolerant to such incompleteness and convenient for possible use of additional information about the object for the suppression of artifacts. The reconstruction method of folded projections, which is advantageous for limited-angle projection sets, is suggested. Examples of reconstructed slices are given for scanning angles 40, 60, and 90 degrees. A specially designed plastic phantom containing metallic inclusions producing strong artifacts was used. The study of these and other reconstruction results in various geometric and noise conditions indicates that the tomosynthesis option producing images of acceptable quality can be implemented in the standard ProGraph-7000 X-ray apparatus and may have considerable area of application.