Sökning: "Dosimeters"

Visar resultat 1 - 5 av 19 avhandlingar innehållade ordet Dosimeters.

  1. 1. Chewing gum and human hair as retrospective dosimeters

    Författare :Axel Israelsson; Håkan B.L. Pettersson; Eva Lund; Håkan Gustafsson; Mats Eriksson; Bastian Breustedt; Linköpings universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES;

    Sammanfattning : Retrospective dosimeters are sometimes needed after radiological/nuclear (RN) exposures to determine the doses to individuals. Conventional dosimeters may not be at hand or may not be applicable calling for alternative materials. LÄS MER

  3. 2. Lithium formate EPR dosimetry for accurate measurements of absorbed dose in radiotherapy

    Författare :Emelie Adolfsson; Åsa Carlsson Tedgren; Eva Lund; Håkan Gustafsson; Sara Olsson; Gudrun Alm Carlsson; Peter Sharpe; Linköpings universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES;

    Sammanfattning : Lithium formate has shown to be a material with properties suitable for electron paramagnetic resonance (EPR) dosimetry, among them up to 7 times higher sensitivity compared to alanine, which is a well-established EPR detector material for dose determinations in radiotherapy.The aim of this thesis was to further investigate the properties of lithium formate and develop the dosimetry system towards applications in radiotherapy. LÄS MER

  4. 3. MRI evaluation and image processing in gel dosimetry. A study of selected MRI properties and image processing in 3D gel dosimetry

    Författare :Peter Magnusson; Malmö Medicinsk strålningsfysik; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Klinisk fysiologi; medical instrumentation; tomography; radiology; Clinical physics; image registering; multi-slice; slice profile; ferrous sulphate; polyacrylamide; 3D volume acquisition; RF field; B1 field; relaxation time; T1; T2; spin-echo; multi-spin-echo; stochastic noise; nonuniformity; SNR; radiologi; tomografi; medicinsk instrumentering; Radiopharmaceutical technology; Radiofarmaceutisk teknik; Physics; Fysik;

    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

  5. 4. Development of sensitive EPR dosimetry methods

    Författare :Håkan Gustafsson; Eva Lund; Anders Lund; Dag Rune Olsen; Linköpings universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Electron paramagnetic resonance EPR ; Formic acids; pharmacology; Lithium; Nickel; Radiometry; Rhodium; Pharmaceutical chemistry; Farmaceutisk kemi;

    Sammanfattning : Electron paramagnetic resonance (EPR) dosimetry using the well established dosimeter material alanine is a generally accepted dosimetric method for measurements of high absorbed doses. Alanine EPR dosimetry is however not sensitive enough for high precision measurements of low (< 5 Gy) absorbed doses using reasonably measurement times and small dosimeters. LÄS MER

  7. 5. Characterization and Clinical Application of Normoxic Polymer Gel in Radiation Therapy Dosimetry

    Författare :Anna Karlsson; Malmö Medicinsk strålningsfysik; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; 3D dose verification; uncertainties; low-density gel; fractionation dependence; characterization; normoxic gel; polymer gel dosimetry; MRI; Physics; Fysik;

    Sammanfattning : Cancer is one of the main causes of death in the world, particularly in developing countries and is considered as a major public health problem. Radiation therapy has been an important modality for treatment of cancer for many decades. LÄS MER