Accession Number : ADA182146

Title :   An Application of the Finite Element Method to Maximum Entropy Tomography Image Reconstruction.

Descriptive Note : Technical rept. 1984-1986,

Corporate Author : ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD

Personal Author(s) : Smith,Robert T ; Zoltani,Csaba K

PDF Url : ADA182146

Report Date : 07 Apr 1987

Pagination or Media Count : 28

Abstract : A new approach to maximum entropy tomographic image reconstruction is condsidered here. It is shown that by using a finite dimensional subspace of L sub 2 (D), one can obtain an approximation to the solution of a maximum entropy optimization problem, set in L sub 2 (D). Several examples of appropriate finite element subspaces for a 2-dimensional parallel beam projection geometry are examined. Particular attention is paid to the case where the x-ray projection data is sparse. In the current work, this means that the number of projections or views is small (in practice, perhaps only 15 to 20, as compared with the 180 views used in modern medical CAT scanners). A priori information in the form of known maximum and minimum densities of the materials being scanned is built into the model. A penalty function, added to the entropy term, is used to control the residual error in meeting the projection measurements. Keywords: Optimization; X ray attenation; Approximation(Mathematics).

Descriptors :   *X RAY DIAGNOSTICS, *COMPUTERIZED TOMOGRAPHY, *X RAY ABSORPTION ANALYSIS, *COMPUTER APPLICATIONS, SOLUTIONS(GENERAL), ENTROPY, OPTIMIZATION, ERRORS, RESIDUALS, X RAYS, DENSITY, MATERIALS, FINITE ELEMENT ANALYSIS, MEASUREMENT

Subject Categories : Medicine and Medical Research
      Numerical Mathematics
      Medical Facilities, Equipment and Supplies
      Computer Programming and Software

Distribution Statement : APPROVED FOR PUBLIC RELEASE