Sökning: "Gudrun Alm-Carlsson"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden Gudrun Alm-Carlsson.

1. 1. 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

3. 2. Calibration of Ionization Chambers for Measuring Air Kerma Integrated over Beam Area in Diagnostic Radiology

   Författare :Peter Larsson; Gudrun Alm Carlsson; Jan Persliden; Bertil Axelsson; Linköpings universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; KAP-meter; DAP-meter; PKA; kerma area product; energy dependence; calibration; Radiological physics; Radiofysik;

   Sammanfattning : The air kerma area product PKA is an important quantity used by hospital physicists in quality assurance and optimization processes in diagnostic radiology and is recommended by national authorities for setting of diagnostic reference levels. PKA can be measured using a transmission ionization chamber (kerma area product (KAP) meter) mounted on the collimator housing. LÄS MER

4. 3. Radioluminescence : A simple model for fluorescent layers

   Författare :Jan Lindström; Eva Lund; Michael Sandborg; Gudrun Alm-Carlsson; Linköpings universitet; []
   Nyckelord :Extrinsic efficiency; extinction factor; radioluminescence; modelling; Monte Carlo; optical attenuation; optimisation; particle size; phosphor; scintillator; MEDICINE; MEDICIN;

   Sammanfattning : The aim of this thesis is to present a simple model for the radiation to light conversion processes in fluorescent layers as an aid in future developments and applications. Optimisation between sensitivity and spatial resolution for fluorescent layers in digital radiology is a delicate task where the extrinsic efficiency for various phosphors needs to be established for varying parameters. LÄS MER

5. 4. Calculation of scatter in cone beam CT : Steps towards a virtual tomograph

   Författare :Alexandr Malusek; Michael Sandborg; Gudrun Alm Carlsson; Michael Ljungberg; Linköpings universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Radiology; Radiologi;

   Sammanfattning : Scattered photons—shortly scatter—are generated by interaction processes when photon beams interact with matter. In diagnostic radiology, they deteriorate image quality since they add an undesirable signal that lowers the contrast in projection radiography and causes cupping and streak artefacts in computed tomography (CT). LÄS MER

7. 5. Quantification and optimisation of lung ventilation SPECT images

   Författare :Pernilla Norberg; Michael Sandborg; Gudrun Alm Carlsson; Agneta Gustafsson; Katarina Sjögreen Gleisner; Linköpings universitet; []
   Nyckelord :;

   Sammanfattning : Currently, lung function tests are the gold standard for lung function measurements. Since the outcome of a lung function test is a summation of the status of the whole lung, significant changes in lung function may occur before a deviation from the norm can be identified. LÄS MER