Search for dissertations about: "Radiology"

Showing result 21 - 25 of 530 swedish dissertations containing the word Radiology.

2. 21. Absorbed Dose Determination and Characteristics of Degraded Electron Beams: Application to Intraoperative Radiation Therapy

   Author : Peter Björk; Internmedicin - epidemiologi; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Clinical physics; radiology; tomography; medical instrumentation; Klinisk fysiologi; radiologi; tomografi; medicinsk instrumentering; absorbed dose distribution; output factor; stopping-power ratio; beam characteristics; Monte Carlo calculation; electron beam dosimetry; applicator system; radiation therapy; linear accelerator; intraoperative radiotherapy;

   Abstract : The aim of this work was to quantify limitations of and uncertainties in commonly used dosimetric techniques for relative absorbed dose determination in degraded electron beams, such as those encountered in intraoperative radiation therapy (IORT) and small-electron-field radiotherapy. Three different detector types were investigated with regard to measurements of output factors and relative absorbed dose distributions: (1) a parallel-plate ionization chamber, (2) a p-type silicon diode detector and (3) a diamond detector. READ MORE

4. 22. Proton Magnetic Resonance Spectroscopy in Brain Tumors - Clinical Applications

   Author : Isabella Björkman-Burtscher; Lund Diagnostisk radiologi; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; radiology; Clinical physics; Localization; Abscess; Brain; Tumor; Spectroscopy; Magnetic Resonance; tomography; medical instrumentation; Klinisk fysiologi; radiologi; tomografi; medicinsk instrumentering;

   Abstract : 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. READ MORE

5. 23. Radiography and bone scintigraphy in osteoarthritis of the knee: comparison with MR imaging

   Author : Torsten Boegård; Lund Diagnostisk radiologi; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; radiologi; Klinisk fysiologi; medical instrumentation; tomography; radiology; Clinical physics; MR imaging; bone scintigraphy; osteophyte; joint space width; weight-bearing; radiograms; Knee joint; osteoarthritis; tomografi; medicinsk instrumentering;

   Abstract : The aim was to compare radiography of the tibiofemoral joint (TFJ) and the patellofemoral joint (PFJ), as well as bone scinigraphy with MR imaging in middle-aged individuals with chronic knee pain in the format of a prospective study of knee osteoarthritis. Individuals aged 35-54 years with chronic knee pain were identified. READ MORE

6. 24. Laser Doppler Flowmetry and Imaging: Methodological Studies

   Author : Siv Bornmyr; Malmö Institutionen för kliniska vetenskaper; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Clinical physics; digital photography.; cold intolerance; sympathetic nervous system; flow cessation external pressure; skin temperature; thermography; skin blood flow; laser doppler imaging; Laser doppler flowmetry; radiology; tomography; medical instrumentation; Klinisk fysiologi; radiologi; tomografi; medicinsk instrumentering;

   Abstract : Laser Doppler flowmetry (LDF) and laser Doppler imaging (LDI) are modern methods for non-invasive and continuous assessment of skin blood flow. The techniques are based on the phenomenon that monochromatic light transilluminating a perfused tissue is spectrally broadened owing to scattering by moving blood cells. READ MORE

7. 25. Degradation, Metabolism and Relaxation Properties of Iron Oxide Particles for Magnetic Resonance Imaging

   Author : Karen Briley Saebo; Håkan Ahlström; Atle Bjørnerud; Michael Knopp; Uppsala universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Radiology; Magnetic Resonance Imaging; contrast agents; iron oxide particles; metabolism; relaxation mechanisms; Radiologisk forskning; Radiological research; Radiologisk forskning;

   Abstract : Whereas the effect of size and coating material on the pharmacokinetics and biodistribution of iron oxide based contrast agents are well documented, the effect of these parameters on liver metabolism has never been investigated. The primary purpose of this work was to evaluate the effect of iron oxide particle size and coating on the rate of liver clearance and particle degradation using a rat model. READ MORE