Magnetic resonance imaging and spectroscopy at ultra high fields [Elektronische Ressource] / vorgelegt von Thomas Neuberger

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Sujets

• Physik

Informations

• Publié par: julius-maximilians-universitat_wurzburg
• Publié le: 01 janvier 2008
• Nombre de lectures: 20
• Langue: Deutsch
• Poids de l'ouvrage: 7 Mo

Extrait

Magnetic Resonance Imaging and Spectroscopy
at ultra high fields








Dissertation zur Erlangung des
naturwissenschaftlichen Doktorgrades
der Bayerischen Julius-Maximilians-Universität Würzburg
vorgelegt von





Thomas Neuberger





aus Miltenberg





Würzburg

2008




ii



















Eingereicht am: 26.02.2008


bei der Fakultät für Physik und Astronomie




1. Gutachter: Prof. Peter Jakob

2. Gutachter: Prof. Andrew Webb

der Dissertation.





1. Prüfer: Prof. Peter Jakob

2. Prüfer: Prof. Andrew Webb

3. Prüfer: Prof.Georg Reents

im Promotionskolloquium.


Tag des Promotionskolloquiums: 23.06.2009


Doktorurkunde ausgehändigt am:
iii





iv Contents
Contents

CONTENTS....................................................................................................................................................I
1 INTRODUCTION ................................................................................................................................3
2 THEORY .............................................................................................................................................. 7
2.1 PROTON IN A MAGNETIC FIELD.................................................................................................... 7
2.2 EXCITATION................................................................................................................................10
2.3 RELAXATION .............................................................................................................................. 10
2.4 NMR SIGNAL ............................................................................................................................. 14
2.5 SIGNAL TO NOISE RATIO (SNR)............................................................................................... 14
2.6 CHEMICAL SHIFT ....................................................................................................................... 15
2.7 MAGNETIC FIELD GRADIENTS AND A MRI EXPERIMENT........................................................... 16
2.8 THE MRS EXPERIMENT............................................................................................................. 18
2.9 SPECTROSCOPIC IMAGING........................................................................................................ 23
2.10 NMR PROPERTIES OF SODIUM ................................................................................................. 25
2.11 RF RESONATORS...................................................................................................................... 28
2.12 BIOLOGICAL BACKGROUND ....................................................................................................... 33
3 HARDWARE SETUP....................................................................................................................... 37
3.1 THE AVANCE 750 SPECTROMETER.......................................................................................... 37
3.2 RF RESONATORS...................................................................................................................... 38
3.2.1 Sodium Resonators for the 200mT/m gradient system..............................................38
3.2.2 m Resonator for the 1T/m gradient system........................................................38
3.2.3 Proton Resonators for the 200 mT/m gradient system...............................................42
3.3 ANIMAL HANDLING SYSTEM...................................................................................................... 42
234 NA IMAGING OF RODENTS...................................................................................................... 45
4.1 METHODS................................................................................................................................... 45
4.1.1 DWCSI.................................................................................................................................46
4.1.2 Data reconstruction of DWCSI........................................................................................48
4.1.3 Measuring T1 with DWCSI...............................................................................................48
4.1.4 Measuring T2 with DWCSI...............................................................................................49
4.2 PHANTOM EXPERIMENTS .......................................................................................................... 50
4.2.1 The effect of k-space undersampling on the point spread function..........................50
4.2.2 T1 measurements..............................................................................................................51
4.2.3 T2 measnts..............................................................................................................53
4.2.4 Temperature dependence of T1 and T2........................................................................54
4.3 SODIUM DWCSI OF RAT AND MOUSE BRAIN.......................................................................... 54
4.3.1 Sodium MRI of the healthy Rat Brain.............................................................................55
4.3.2 Sodium MRI of a Stroke Model in the Rat Brain..........................................................59
4.3.3 m MRI of Stroke Models in the Mouse Brain......................................................62
4.4 THE MOUSE HEART – A FEASIBILITY STUDY............................................................................ 67
4.5 RENAL IMAGING OF THE MOUSE............................................................................................... 74
4.5.1 The kidney function............................................................................................................74
4.5.2 Feasibility of renal mouse MRI........................................................................................75
4.5.3 The sodium signal during diuresis: A time course study............................................80
4.5.4 T1 and T2 Measurements................................................................................................84
5 IN VIVO PROTON SPECTROSCOPY......................................................................................... 87
5.1 PHANTOM EXPERIMENTS .......................................................................................................... 88
5.1.1 Introduction..........................................................................................................................88
5.1.2 Material and Method..........................................................................................................88
5.1.3 Results.................................................................................................................................90
5.1.4 Discussion...........................................................................................................................93
5.2 RAT AND MOUSE BRAIN IN VIVO SPECTROSCOPY.................................................................. 95
5.2.1 Introduction..........................................................................................................................95 Contents
5.2.2 Material and Method..........................................................................................................96
5.2.3 Results..................................................................................................................................97
5.2.4 Discussion............................................................................................................................99
5.3 T1 AND T2 OF MAJOR BRAIN METABOLITES AT VERY HIGH FIELDS........................................100
5.3.1 Introduction........................................................................................................................100
5.3.2 Material and Methods......................................................................................................100
5.3.3 Results................................................................................................................................104
5.3.4 Discussion..........................................................................................................................108
6 IRON LABELED STEM CELL IMAGING ..................................................................................111
7 CONCLUSION.................................................................................................................................123
8 KURZE ZUSAMMENFASSUNG .................................................................................................127
9 BIBLIOGRAPHY.............................................................................................................................131
10 DANKS