A method for producing quantitatively accurate, three-dimensional images of the structures of the body, or in the case of nuclear medicine, the distribution of radio-activity within these structures has been a tantalizing but elusive goal of medical research for many years. Among the many approaches that have been tried, those coming closest to success have been the various forms of tomographic or section imaging. The form of tomography known as transverse axial or transverse section tomography is particularly attractive in terms of quantitative accuracy because information from parts of the object outside the plane of interest does not appear in the final image as it does in other forms of tomography.