Monte Carlo studies on proton computed tomography using a silicon strip detector telescope

Abstract

Monte Carlo computer programs such as the GEANT4 toolkit include precise models of particle interactions and can be an invaluable tool for studying the feasibility of new imaging techniques such as proton computed tomography (pCT). Presented in this paper is a comparison of laboratory data with GEANT4 predictions for the imaging characteristics of a simple metal object using a particle beam and a silicon particle detector.

Proton Radiography Studies for Proton CT

“…6 the required dose to resolve a density difference of ∆ρ = 1.2 g/cm 3 with respect to background is shown for two different voxel sizes. The experimental relationship agrees well with what is expected from (5). In addition, the lower resolution limit from the requirement to have at least 10 protons for the fit of the energy spectrum is shown.…”

“…Dose-voxel-size-contrast relationship for the experimental density increment ∆ρ = 1.2 g/cm 3 . The broken line indicates the power law of (5) matched to the lower experimental point. The line labeled "counting limit" is based on the fact that the energy determination required at least 10 protons.…”

“…The long-term goal of our project is to develop the capability to use proton CT (pCT) instead of x-ray CT to minimize these uncertainties from the current value of 3-10 mm to 1-3 mm. Previous work reviewed in [2] and our own preliminary studies [3][4][5][6][7][8][9] indicate that proton CT based on tracking of individual protons traversing an object from many different directions and measuring their energy loss and scattering angle may yield accurate reconstructions of electron density maps with good density and spatial resolution, despite the fundamental limitation of energy straggling and multiple Coulomb scattering (MCS). Fig.…”

Toward Proton Computed Tomography

“…Here, the code was used to define cuts on the data to optimize spatial resolution and contrast of the proton images. Details of the simulations are given in [28], which showed excellent agreement between data and simulated angular distributions. The angular spread for protons, which traverse the pipe in its entirety, is about 5 , and for protons, which miss the pipe completely about 1 .…”

“…They also show "edge enhanced" images taken with the same data, when the rms exit range variation is plotted versus entrance and -making use of the multiple scattering phenomenon. In a manner similar to the iterative reconstruction programs used in PET and SPECT, the detailed information from the detector, such as the angle of deflection of the proton and the final energy of the proton can be modeled, using the basic physics of the process [6], [7], [28].…”