Pediatric personalized CT-dosimetry Monte Carlo simulations, using computational phantoms

[摘要] The last 40 years Monte Carlo (MC) simulations serve as a "gold standard" tool for a wide range of applications in the field of medical physics and tend to be essential in daily clinical practice. Regarding diagnostic imaging applications, such as computed tomography (CT), the assessment of deposited energy is of high interest, so as to better analyze the risks and the benefits of the procedure. The last few years a big effort is done towards personalized dosimetry, especially in pediatric applications. In the present study the GATE toolkit was used and computational pediatric phantoms have been modeled for the assessment of CT examinations dosimetry. The pediatric models used come from the XCAT and IT'IS series. The X-ray spectrum of a Brightspeed CT scanner was simulated and validated with experimental data. Specifically, a DCT-10 ionization chamber was irradiated twice using 120 kVp with 100 mAs and 200 mAs, for 1 sec in 1 central axial slice (thickness = 10mm). The absorbed dose was measured in air resulting in differences lower than 4% between the experimental and simulated data. The simulations were acquired using ∼1010number of primaries in order to achieve low statistical uncertainties. Dose maps were also saved for quantification of the absorbed dose in several children critical organs during CT acquisition.

[发布机构] Department of Medical Physics, Medical School, University of Patras, GR 26504, Greece^1;Department of Radiology, Medical School, National and Kapodistrian University of Athens, GR 12462, Greece^2;Department of Radiology, Medical School, National Kapodistrian University of Athens, GR 11528, Greece^3;Radiology Research Unit, Medical Imaging Department, National and Kapodistrian University of Athens, Athens; 11528, Greece^4;MRI-CT Medical Imaging Department, General Childrens Hospital of Athens Ag. Sophia, Greece^5;Department of Biomedical Engineering, Technological Educational Institute of Athens, GR 12210, Greece^6

[效力级别] 医药卫生 [学科分类] 卫生学

[关键词] Clinical practices;Computational phantom;Critical organs;Ct acquisitions;Deposited energy;Diagnostic imaging;Medical physics;Statistical uncertainty