magistrsko delo
Kaja Tušar (Author), Igor Serša (Mentor)

Abstract

V magistrskem delu bomo najprej predstavili standardni način dvodimenzionalnega magnetnoresonančnega slikanja z uporabo standardnih linearnih gradientnih tuljav, ki proizvajajo prostorsko linearno odvisno magnetno polje. Nato bomo obravnavali alternativno magnetnoresonančno slikanje z uporabo nestandardnih nelinearnih gradientnih tuljav, kjer ima njihovo magnetno polje bolj splošno prostorsko odvisnost. Kot primer bomo predstavili preprosto gradientno tuljavo z obliko pravokotne zanke, kjer le ena stranica z ravnim odsekom žice ustvarja za slikanje pomemben gradient magnetnega polja. Geometrijske deformacije v MR slikah lahko izračunamo iz prostorske porazdelitve projekcije magnetnega polja $B_z$ gradientne tuljave. Izdelali smo model takšne tuljave in z njo opravili slikanje. Dobljene slike smo nato primerjali s teoretično napovedanimi. Razumevanje popačitev v MR slikah pri uporabi nelinearnih gradientnih tuljav nam omogoči, da lahko rekonstruiramo geometrijsko nepopačene slike tudi z uporabo takšnih tuljav. To je lahko koristno, ker lahko oblikujemo tovrstne nekonvencionalne tuljave na način, ki nam pomaga odpraviti raznovrstne slabosti standardnih gradientnih tuljav.

Keywords

jedrska magnetna resonanca;magnetnoresonančno slikanje;gradientna tuljava;nelinearno magnetno polje;popačitve slik;3D tiskanje;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FMF - Faculty of Mathematics and Physics
Publisher: [K. Tušar]
UDC: 537.635
COBISS: 74564355 Link will open in a new window
Views: 408
Downloads: 47
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Other data

Secondary language: English
Secondary title: Magnetic Resonance Imaging with Use of Nonlinear Gradient Coils
Secondary abstract: In this thesis we present the standard way of making two-dimensional magnetic resonance images with use of standard linear gradient coils that feature spatially linear magnetic fields. We also discuss the alternative imaging with non-standard non-linear gradient coils that have more general spatial magnetic field dependency. As an example, we will present a simple gradient coil with the shape of a rectangle, where only a single edge produces for imaging significant gradient of the magnetic field. Image distortions can be calculated from the known spatial dependency of the magnetic field $B_z$ of the gradient coil. We made a model of such coil and used it for imaging. We used produced images to compare theoretical predications with the experimental results. Understanding of image distortions due to the use of nonlinear gradient coil designs enables us to reconstruct distortion-free images acquired by the use of such coils. This can be beneficial as these special coils can be designed to reduce specific weaknesses of standard gradient coils.
Secondary keywords: nuclear magnetic resonance;magnetic resonance imaging;gradient coil;nonlinear magnetic field;image distortion;3D printing;
Type (COBISS): Master's thesis/paper
Study programme: 0
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za matematiko in fiziko, Oddelek za fiziko
Pages: 70 str.
ID: 13268065