The synthesis of a new X-ray picture identical in projection to a previous picture using 3D Fourier techniques

• Published in: Physics in medicine & biology Vol. 39; no. 3; pp. 597 - 608
• Main Authors: Carlsson, P E, Edholm, P R, Danielsson, P -E
• Format: Journal Article
• Language: English
• Published: England IOP Publishing 01.03.1994
• Subjects: Algorithms; Fourier Analysis; Humans; Image Processing, Computer-Assisted - instrumentation; Image Processing, Computer-Assisted - methods; Imaging, Three-Dimensional - methods; Models, Statistical; Models, Theoretical; Radiographic Image Enhancement - methods; Technology, Radiologic - methods; Tomography, X-Ray Computed; X-Rays
• ISSN: 0031-9155; 1361-6560
• DOI: 10.1088/0031-9155/39/3/021

A central problem in diagnostic radiology is to compare a new x-ray picture with a previous picture and from this comparison be able to decide whether anatomical changes have occurred in the patient or not. It is of primary interest that these pictures are identical in projection. If not it is difficult to decide with confidence whether differences between the pictures are due to anatomical changes or differences in projection. In this paper we present the geometrical problem and introduce some assumptions that make it possible to find the relative changes in the projection geometry between the exposure of a previous picture and a new picture. The method presented is based on the projection slice theorem (central section theorem). By used 3D Fourier transform techniques we are able to synthesize a new x-ray picture from a set of pictures exposed from a circular orbit above the patient.