In-vivo Proton Magnetic Resonance Spectroscopy: Evaluation of Multiple Quantum Techniques for Spectral Editing and a Time Domain Fitting Procedure for Quantification

摘要

The publication is comprised of an introduction in chapter 1 and the following subjects. In chapter 2 a detailed description is given of several aspects concerning the use of multiple quantum coherence techniques for in-vivo studies. In chapter 3 it is shown that a zero quantum sequence can be used to selectively measure lactate and that this sequence can be combined with a localization technique. In chapter 4, editing techniques to separate signals from two complex spin systems (glutamate and glutamine) are described. Since it appeared to be very difficult to selectively measure one of these systems and suppress the other with multiple quantum coherence techniques, an alternative method is also given. Pathophysiological mechanisms are studied which are responsible for the induction of hepatic encephalopathy. Results of the study are described in chapter 5. Chapter 6 is concerned with data processing techniques. It is described how prior knowledge is incorporated in a Gauss-Newton iterative fitting procedure. Concluding remarks and a summary are given in chapter 7.