Sökning: "mr spectroscopy"

Visar resultat 1 - 5 av 25 avhandlingar innehållade orden mr spectroscopy.

1. 1. 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

3. 2. Parametric methods for frequency-selective MR spectroscopy

   Författare :Niclas Sandgren; Peter Stoica; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering with specialization in Signal Processing; Elektroteknik med inriktning mot signalbehandling;

   Sammanfattning : Accurate and efficient quantitation of the data components in magnetic resonance spectroscopy (MRS) signals can be an important step in the analysis of biochemical substances. In several practical applications of MR spectroscopy the user is interested only in the data components lying in a small frequency band of the spectrum. LÄS MER

4. 3. Maximum likelihood estimation in signal analysis of MR spectroscopy

   Författare :Pia Löthgren; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Proton magnetic resonance spectroscopy (MRS) is used to determine the concentration of metabolites in organic tissues, or to study metabolic changes in a non-invasive way. The complex-valued magnetic resonance spectroscopy signals are assumed to be disturbed by additive white noise. LÄS MER

5. 4. Contrast-Enhanced Magnetic Resonance Angiography - Development and optimization of techniques for paramagnetic and hyperpolarized contrast media

   Författare :Jonas Svensson; Malmö Medicinsk strålningsfysik; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; egenskaper elektriska; Kondenserade materiens egenskaper:elektronstruktur; spectroscopy; relaxation; Angiography; Magnetic resonance; Contrast-enhanced; Hyperpolarized; Condensed matter:electronic structure; 13C; supraconductors; electrical; magnetic and optical properties; magnetiska och optiska ; supraledare; magnetisk resonans; spektroskopi;

   Sammanfattning : Contrast-enhanced magnetic resonance angiography (CE-MRA) is a diagnostic method for imaging of vascular structures based on nuclear magnetic resonance. Vascular enhancement is achieved by injection of a contrast medium (CM). LÄS MER

7. 5. Positron Emission Tomography and Magnetic Resonance Techniques in Diabetes

   Författare :Lina Carlbom; Håkan Ahlström; Olle Korsgren; Olof Eriksson; Lars Johansson; Tove Grönroos; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Positron emission tomography; Magnetic resonance imaging; Magnetic resonance spectroscopy; Type 1 diabetes; Type 2 diabetes; PET MR; Pancreas transplantation; Perfusion; Radiology; Radiologi;

   Sammanfattning : In order to further advance the field of diabetes research there is a great need for establishing validated non-invasive quantitative techniques to study the pancreas and other tissues of importance for blood glucose regulation. The general aim of this thesis was to explore magnetic resonance techniques and positron emission tomography as such tools. LÄS MER