Sökning: "Clinical physics"
Visar resultat 1 - 5 av 165 avhandlingar innehållade orden Clinical physics.
1. Irradiation of members of the general public from radioactive caesium following the Chernobyl reactor accident. Field studies in a highly contaminated area in the Bryansk region, Russia
Sammanfattning : From 1990 to 1998, estimations of the effective dose from external as well as internal irradiation from 137Cs and 134Cs were carried out for inhabitants in rural villages in the Bryansk region, Russia, highly contaminated due to the Chernobyl accident in 1986. The villages were situated about 180 km from the Chernobyl power plant and the deposition of 137Cs was in the range 0. LÄS MER
2. MRI evaluation and image processing in gel dosimetry. A study of selected MRI properties and image processing in 3D gel dosimetry
Sammanfattning : Gel dosimetry is a new dosimetry method applied in radiation therapy. Gel dosimeters consist of a radiation sensitive gel, which can integrate absorbed doses from several radiation sources or beams. The dose to the gel can be evaluated by magnetic resonance imaging (MRI), a procedure that is the focus of the present thesis. LÄS MER
Sammanfattning : Early detection is vital to successfully treating breast cancer, and mammography screening is the most efficient and wide-spread method to reach this goal. Imaging low-contrast targets, while minimizing the radiation exposure to a large population is, however, a major challenge. LÄS MER
4. The matter of white matter in Alzheimer's disease. -On white matter disease from neuropathology and neuroimaging to clinical presentation
Sammanfattning : Alzheimer's disease (AD) is the most prevalent type of dementing disorder. The cortical pathology of AD has been recognized for almost a century. In later years, an associated pathological feature of AD has been identified which affects the white matter. LÄS MER
Sammanfattning : Aims: · to present a test phantom and test method for evaluation of proton magnetic resonance spectroscopy (1H-MRS) single volume localization techniques regarding signal contamination; · to describe the introduction of 1H-MRS in the daily routine of a standard MR-unit; · to evaluate the possibilities offered by 1H-MRS to improve preoperative diagnostic accuracy in patients scheduled for stereotactic biopsy of intracranial mass lesions; · to evaluate the possibilities offered by 1H-MRS to improve diagnostics and therapy control in patients with brain abscesses; · to test the hypothesis that 1H-MRS might be useful for differentiation of brain tumors, based on metabolic changes in tissue across brain lesions or surrounding tissue. Results and conclusions: · The test phantom and test method allow quality assessment with good reproducibility. LÄS MER