Primena virtuelng voksela pri upotrebi CT podataka u modelovanju trajektorije čestice tehnikama Monte Karlo

Abstract

U simulaciji prolaza čestica tehnikama Monte Karlo aktuelni geometrijski moduli upotrebljavaju površine prvog i drugog reda (FOTELP, PENELOPE, SHIELD, GEANT), a nekad i četvrtog reda(MCNP5), da opišu složene geometrijske forme.. Sve veća primena tehnika Monte Karlo u medicini oslanja se na vokselizovane geometrijske forme koje se dobijaju vokselizaciom fantoma ili iz CT podataka. Ogroman broj tela (voxela) u tom slučaju otežava primenu konstruktivne geometrije. Eefikasniji pristup tom problemu zasniva se na primeni virtuelnog voksela.Ovde se saopštavaju rezultati upotrebe virtuelnog voksela na anatomiju tela i organa upotrebom CT podataka.

Geometry modules in particle transport simulation codes with Monte Carlo techniques use surfaces of first and second order, sometimes even a fourth order surfaces, to be able to describe complex geometrical shapes. Constructive quadric geometry dominates in all leading software packages. Increasing application of Monte Carlo techniques in medicine is associated with voxelized geometry forms. Huge number of bodies present in this case makes the use of constructive geometry more difficult. The paper describes an efficient approach to this problem by virtual voxel application, where optical distance to the boundary is obtained, and 3D voxel indices give information about the materials present in voxel.