<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "An abdominal phantom with anthropomorphic\r\norgan motion and multimodal imaging\r\ncontrast for magnetic-resonance-guided\r\nradiotherapy"^^ . "The continuous progress in the field of radiation therapy has led to significant improvements\r\nin the diagnosis and treatment of cancer, resulting in enhanced quality of life and increased life\r\nexpectancy. The development of the MR-Linac marked a paradigm shift in radiation therapy.\r\nThis advancement enables real-time visualization of tumors during radiation therapy using\r\nmagnetic resonance imaging. Consequently, treatment plans can be adjusted to account for\r\nchanges in tumor size between sessions, such as tumor shrinkage, and to incorporate tumor\r\nmovements during each radiation session, for example, due to breathing. This precision allows\r\nfor the delivery of a higher radiation dose directly to the target volume while minimizing\r\nradiation exposure to nearby organs.\r\nThe aim of this work was to develop an anthropomorphic abdominal phantom that meets\r\nseveral requirements: reproducible breathing motions with induced organ motions in a\r\ncomposite, realistic image contrast in both magnetic resonance imaging and computed\r\ntomography, anthropomorphically shaped organ models, and an MRI-compatible motion\r\ncontrol unit.\r\nIn this thesis, an innovative anthropomorphic abdominal phantom for medical imaging and\r\nradiation therapy applications was developed. Through a series of experiments and analyses,\r\nthe capabilities and usefulness of the phantom were rigorously evaluated.\r\nThe organ models used in the experiments demonstrate remarkable accuracy in replicating the\r\nrelaxation times and Hounsfield Units of real human organs. This validation underscores the\r\nsuitability of the phantom for medical imaging research, with the results showing close\r\nagreement with reference values without significant differences.\r\nComparisons between the phantom and patient/volunteer data showed good agreement in\r\nsimulating respiration-induced organ motions in a composite during various breathing patterns\r\n(shallow, free, and deep breathing), anatomical shapes, image contrast, and radiological\r\ncharacteristics.\r\nFurthermore, the analysis of organ motion under different breathing patterns highlights the\r\nphantom's ability to simulate human organ movements, emphasizing the importance of\r\nconsidering organ motions in treatment planning and imaging procedures.\r\nIn summary, this work demonstrated that the developed phantom effectively simulates various\r\nrespiratory movements and corresponding organ motions within a composite structure.\r\nAdditionally, compared to volunteer data, the phantom exhibited comparable image contrast\r\nin magnetic resonance imaging and computed tomography imaging, and stability of image\r\ncontrast over a period of more than 400 days was demonstrated. Moreover, the phantom proved\r\nsuitable for an end-to-end test, encompassing the entire radiation therapy process from imaging\r\nand radiation planning to dose calculation and delivery. This included the insertion of\r\ndosimetric EBT3 films into the liver tumor model. An important outcome was that the\r\nphantom's liver tumor model was successfully detected by the MR-Linac and radiation was\r\nstopped as soon as the tumor moved outside the target volume due to breathing motion.\r\nUltimately, a dose of 5.3 ± 0.42 Gy was calculated within the tumor model, which demonstrates\r\nexcellent alignment with the planned dose of 5 Gy, considering the minimal deviation."^^ . "2025" . . . . . . . "Artur"^^ . "Weidner"^^ . "Artur Weidner"^^ . . . . . . "An abdominal phantom with anthropomorphic\r\norgan motion and multimodal imaging\r\ncontrast for magnetic-resonance-guided\r\nradiotherapy (PDF)"^^ . . . "Weidner_Artur_08_12_1990_Dissertation.pdf"^^ . . . "An abdominal phantom with anthropomorphic\r\norgan motion and multimodal imaging\r\ncontrast for magnetic-resonance-guided\r\nradiotherapy (Other)"^^ . . . . . . "indexcodes.txt"^^ . . . "An abdominal phantom with anthropomorphic\r\norgan motion and multimodal imaging\r\ncontrast for magnetic-resonance-guided\r\nradiotherapy (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "An abdominal phantom with anthropomorphic\r\norgan motion and multimodal imaging\r\ncontrast for magnetic-resonance-guided\r\nradiotherapy (Other)"^^ . . . . . . "preview.jpg"^^ . . . "An abdominal phantom with anthropomorphic\r\norgan motion and multimodal imaging\r\ncontrast for magnetic-resonance-guided\r\nradiotherapy (Other)"^^ . . . . . . "medium.jpg"^^ . . . "An abdominal phantom with anthropomorphic\r\norgan motion and multimodal imaging\r\ncontrast for magnetic-resonance-guided\r\nradiotherapy (Other)"^^ . . . . . . "small.jpg"^^ . . "HTML Summary of #35770 \n\nAn abdominal phantom with anthropomorphic \norgan motion and multimodal imaging \ncontrast for magnetic-resonance-guided \nradiotherapy\n\n" . "text/html" . . . "004 Informatik"@de . "004 Data processing Computer science"@en . . . "530 Physik"@de . "530 Physics"@en . . . "540 Chemie"@de . "540 Chemistry and allied sciences"@en . . . "610 Medizin"@de . "610 Medical sciences Medicine"@en . . . "620 Ingenieurwissenschaften"@de . "620 Engineering and allied operations"@en . . . "660 Technische Chemie"@de . "660 Chemical engineering"@en . .