<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "Gel-based Multimodality (CT/MR) Phantoms for Ion Radiotherapy"^^ . "The importance of magnetic resonance imaging (MRI) in radiation therapy (RT) has\r\nbeen increasing over the past years. In ion RT, due to its high accuracy and sensitivity to\r\nsmall uncertainties, the treatment planning process based on computed tomography (CT)\r\nis currently extended towards MRI. For exploring the potential of new imaging techniques\r\n(such as MRI) multimodality phantoms are mandatory. Hereby, interaction properties\r\nwith photon and ion radiation have to be adjusted independently from the parameters\r\ninfluencing the MR contrasts.\r\nThis Bachelor thesis investigates barium sulfate doped agarose gels as multimodality phantoms\r\nfor application in ion RT. 14 gel-phantoms with different combinations of agarose\r\nand barium sulfate concentrations were manufactured. These gels were assessed in dual\r\nenergy CT (DECT), MRI and carbon ion range measurements.\r\nDECT parameters were adjustable with barium sulfate while the effect of agarose was\r\nminimal: The effective atomic number (Zeff ) showed values from 7.5 to 10, the electron\r\ndensity (pe-) relative to water could be varied from 1.00 to 1.03. CT-numbers at 80kV\r\nallowed variation from 0 to 270HU. Adjustment of absolute relaxation times in MR was\r\npossible by varying the agarose concentration. T1 showed a range from 2000 to 2900ms,\r\nT2 was adjustable from from 20 to 120ms. The influence of barium sulfate on feasible relaxation\r\ntimes was 17% and 12% respectively. The water equivalent path length of carbon\r\nions could be varied by 3%.\r\nFurther investigations with alternative solutes are needed to extend the range of relaxation\r\ntimes and electron density for more realistic tissue simulation. Agarose gel-phantoms\r\nproved to be stable, easy to handle and allowed independent adjustment of DECT- and\r\nMR-parameters. They enable the production of anthropomorphic multimodality phantoms\r\nfor ion RT applications."^^ . "2012" . . . . . . . "Nina Isabelle"^^ . "Niebuhr"^^ . "Nina Isabelle Niebuhr"^^ . . . . . . "Gel-based Multimodality (CT/MR) Phantoms for Ion Radiotherapy (Other)"^^ . . . . . . "indexcodes.txt"^^ . . . "Gel-based Multimodality (CT/MR) Phantoms for Ion Radiotherapy (PDF)"^^ . . . "Final_Bachelorthesis_Nina.pdf"^^ . . . "Gel-based Multimodality (CT/MR) Phantoms for Ion Radiotherapy (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "Gel-based Multimodality (CT/MR) Phantoms for Ion Radiotherapy (Other)"^^ . . . . . . "preview.jpg"^^ . . . "Gel-based Multimodality (CT/MR) Phantoms for Ion Radiotherapy (Other)"^^ . . . . . . "medium.jpg"^^ . . . "Gel-based Multimodality (CT/MR) Phantoms for Ion Radiotherapy (Other)"^^ . . . . . . "small.jpg"^^ . . "HTML Summary of #15479 \n\nGel-based Multimodality (CT/MR) Phantoms for Ion Radiotherapy\n\n" . "text/html" . . . "530 Physik"@de . "530 Physics"@en . .