Sökning: "voxel phantom"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden voxel phantom.

1. 1. Radiation Detection Techniques for the Enhancement of Nuclear Safety

   Författare :Petty Bernitt Cartemo; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; whole body counting; depth profiling; voxel phantom; nuclear safeguards; Monte Carlo; orphan sources; radiation-induced material damage; pulsed beam; positron lifetime;

   Sammanfattning : The hazard originating from the use of nuclear materials in various areas of the society necessitates a number of experimental techniques for controlling and increasing the safety connected to radioactive substances.The following thesis is divided into two parts, representing different aspects to the detection of radiation effects. LÄS MER

3. 2. Evaluation of Intracranial Arteriovenous Malformations with Magnetic Resonance Imaging

   Författare :Maria Correia de Verdier; Johan Wikström; Elisabeth Ronne-Engström; Ljubisa Borota; Johan Wassélius; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Arteriovenous malformation; brain; proton-radiation therapy; magnetic resonance imaging; phase-contrast MRI; Radiology; Radiologi;

   Sammanfattning : Intracranial arteriovenous malformations (AVMs) are characterized by feeding arteries, a tangle of abnormal vessels (nidus) and draining veins. Radiological evaluation methods are used in diagnosing AVMs, treatment planning, post-treatment evaluation and monitoring stability. LÄS MER

4. 3. Neurotransmitter Imaging of the Human Brain : Detecting γ-Aminobutyric Acid (GABA) Using Magnetic Resonance Spectroscopy

   Författare :Sofie Tapper; Peter Lundberg; Anders Tisell; Peter Zsigmond; Richard Edden; Linköpings universitet; []
   Nyckelord :;

   Sammanfattning : Introduction: In this thesis, MEGA-edited Magnetic Resonance Spectroscopy (MRS) has been used for the purpose of non-invasive detection of !- aminobutyric acid (GABA) within the brain. GABA is the main inhibitory neurotransmitter in the human central nervous system, and glutamate is the corresponding main excitatory neurotransmitter. LÄS MER

5. 4. Phase-Contrast X-Ray Imaging of Complex Objects

   Författare :Ilian Häggmark; Hans Hertz; Anna Burvall; Henning Friis Poulsen; KTH; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Fysik; Physics; Biological and Biomedical Physics; Biologisk och biomedicinsk fysik;

   Sammanfattning : X-ray imaging is a group of techniques using electromagnetic radiation of high energy. The ability to quickly visualize internal structures in thick opaque objects has made it an indispensable tool in research, medicine, and industry. LÄS MER

7. 5. Proton Magnetic Resonance Spectroscopy in Brain Tumors - Clinical Applications

   Författare :Isabella Björkman-Burtscher; Lund Diagnostisk radiologi; []
   Nyckelord :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;

   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