%0 Journal Article
%A Amato, Carlo
%A Martisikova, M.
%A Gehrke, Tim
%T A technique for spatial resolution improvement in helium-beam radiography.
%J Medical physics
%V 47
%N 5
%@ 2473-4209
%C College Park, Md.
%I AAPM
%M DKFZ-2020-00286
%P 2212-2221
%D 2020
%Z 2020 Jun;47(5):2212-2221#EA:E040#LA:E040#
%X Ion-beam radiography exhibits a significantly lower spatial resolution (SR) compared to X-ray radiography. This is mostly due the multiple Coulomb scattering (MCS) that the ions undergo in the imaged object. In this work, a novel technique to improve the spatial resolution in helium-beam radiography was developed. Increasing helium-beam energies were exploited in order to decrease the MCS, and therefore increase the SR.The experimental investigation was carried out with a dedicated ion-tracking imaging system fully composed of thin, pixelated silicon detectors (Timepix). Four helium beams with increasing energies (from 168.8MeV/u to 220.5MeV/u) were used to image a homogeneous 160mm PMMA phantom with a 2mm air gap at middle depth. An energy degrader was placed between the rear tracking system and the energy-deposition detector to compensate for the longer range associated with more energetic ions. The SR was measured for each beam energy. To take into account the overall impact on the image quality, the contrast-to-noise ratio (CNR), the single-ion water equivalent thickness (WET) precision and the absorbed dose in the phantom were also evaluated as a function of the initial beam energy. FLUKA Monte Carlo simulations were used to support the conceptual design of the experimental setup and for dose estimation.In the investigated energy interval, a total SR increase by around 30
%F PUB:(DE-HGF)16
%9 Journal Article
%$ pmid:31995641
%R 10.1002/mp.14051
%U https://inrepo02.dkfz.de/record/153435