Graduate theses
Current Record: 53 of 179
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Title |
Μετρήσεις θερμοκρασίας με μεθόδους ποσοτικής απεικόνισης μαγνητικού συντονισμού (πΑΜΣ) μέσα σε κλινικό σύστημα ΑΜΣ, εφαρμόζοντας τεχνικές υβριδικής ήπιας υπερθερμίας μικροκυμάτων σε δείγματα IN-VITRO |
Alternative Title |
Temperature measurements with quantitative magnetic resonance imaging (qMRI) techniques inside a clinical MRI system, applying hybrid mild microwave hyperthermia methods for specific samples IN-VITRO |
Author
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Μεταξάκη, Μαρία – Άννα
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Thesis advisor
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Μαρής, Θωμάς Γ.
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Reviewer
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Κομίνης, Ιωάννης
Καραντάνας, Απόστολος
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Abstract |
Hyperthermia is a method of synergistic treatment of malignancies (synergy with
radiotherapy and/or chemotherapy). Clinically, hyperthermia is defined as the provision of a
desired and controlled form of heat to areas of the disease, ranging from 42°C to 45°C, while
simultaneously protecting adjacent healthy tissues from irreversible damage.
Mild hyperthermia has generated a lot of interest, as it is a non-invasive therapeutic
technique that has been shown to be quite effective in clinical treatment. However, the issue of
temperature monitoring suppresses its development.
Magnetic Resonance Imaging (MRI) is one of the methods under investigation for noninvasive thermometry. Magnetic recovery times are temperature dependent and can be
accounted for by image thermometric parameters. A major advantage of MRI over other
imaging modalities, in addition to using non-ionizing radiation, is that it can produce highcontrast images of soft tissues based on intrinsic tissue characteristics. Three common contrast
methods utilized in clinical applications are proton density–weighted contrast, T1−weighted
contrast, and T2−weighted contrast.
During the experimental process, using a microwave diathermy antenna, firstly we created
hyperthermia states in four (4) samples of Sodium Chloride (NaCl) solutions simulating tissues
with high values of the T2 parameter, and secondly we created the same states in thirty two
solutions (32) with contents simulating properties of various biological tissues in a wide range
of T2 values. Using an MRI system we visualized and correlated the effects of induced
hyperthermia.
The purpose of this experimental work was to design new sequences for the correct and
more efficient study of biological tissue materials in mild hyperthermia conditions. In
particular, the aim was to expand fast T2 measurements for materials with short T2 times (50
– 300ms) simulating living soft tissues, in combination with materials with long T2 times (>400)
simulating body fluids.
Finally, a comparison was made between the well-known MESE sequence and the HASTE
sequence, a sequence commercialized by Siemens.
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Language |
Greek |
Issue date |
2022-11-25 |
Collection
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School/Department--School of Sciences and Engineering--Department of Physics--Graduate theses
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Type of Work--Graduate theses
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Permanent Link |
https://elocus.lib.uoc.gr//dlib/6/f/2/metadata-dlib-1666335360-422597-1330.tkl
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Views |
162 |