Visar resultat 1 - 5 av 73 avhandlingar innehållade ordet tomografi.
1. Image Processing for Quantitative Scintillation-Camera Imaging. Application to Radionuclide Therapy
Sammanfattning : Individual-based determinations of the absorbed dose in radionuclide therapy largely rely on absolute measurement of the activity distribution and its redistribution over time. Scintillation-camera imaging is the most commonly employed measuring technique, applied in planar or SPECT mode, sometimes in combination with structural images from CT. LÄS MER
Sammanfattning : Positron emission tomography (PET) is a tracer technique used for quantitative in vivo studies of physiological and biochemical processes. Because of the use of positron-emitting radionuclides such as 11-C, 13-N, 15-O and 18-F, which are isotopes of the biologically ubiquitous elements, it is possible to label radiopharmaceuticals which trace biochemical processes precisely. 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
Sammanfattning : The diagnostic value of modern fast pulse sequences and breath-hold technique was evaluated in a prospective study of patients with suspected biliary diseases. The cost-effectiveness of MRI compared to ultrasound was calculated. LÄS MER
Sammanfattning : In the studies of this thesis, a method for automated classification of myocardial perfusion images was successfully developed and evaluated. The results show that the method, based on artificial neural networks, was equally good, or even better than human experts. LÄS MER