Object description by a maximum rectangular method in Monte Carlo simulation

The photon transportation simulation which uses a Monte Carlo method is an indispensable technique for examining the scatter and absorption correction methods in SPECT and PET. The authors have developed a method for object description in maximum regions (maximum rectangular regions: MRRs) to speed up photon transportation simulation, and compared the calculation time with that of conventional object description methods. In this paper details of the expansion of MRR to three dimensions are given. Moreover, the effectiveness the proposed method was compared with the VB and octree method in the results of simulations of two kinds of phantoms