| dc.description.abstract | Background: Information on the metabolic content in tissue has diagnostic and prognostic
value when examining for example cancer and diseases of the brain. MR
spectroscopy is a non-invasive method that allows quantification of
metabolite concentrations in vivo, without the use of ionizing radiation, which
makes the method highly attractive for both research and clinical applications.
However, specialized software is required for generation of so called basis
sets, which consist of information on the individual metabolites that are under
investigation, and which are required for quantification. Furthermore,
method- and MR vendor-specific information must be provided as the basis
sets are being generated in order to yield reliable quantification results.
A software for generation of basis sets was recently developed at the
University of Gothenburg and validated for a preclinical MR system in a
previous master thesis project. However, a standardized method for
calculation of metabolite concentrations in vivo in the preclinical setting has
not yet been developed.
Therefore, the purpose of this work was to adapt, validate and apply a method
for non-invasive quantification of metabolites from in vivo MR spectroscopy
at the preclinical facility at the University of Gothenburg.
Method: The software, implemented in MATLAB and previously developed to
simulate basis sets for the clinical MR system, was programmatically adapted
to import pulse sequence parameters from the preclinical MR system.
Validation of the adapted MATLAB software was done by MR spectroscopy
measurements on a phantom solution with known concentrations of certain
metabolites, followed by metabolite quantification using the LCModel
software. Two in vivo experiments were performed to assess the applicability
of the method in the preclinical setting: one on the healthy mouse brain and
one on a mouse model of human cancer. The point resolved spectroscopy
(PRESS) pulse sequence was used for all measurements and simulations.3
Results: The adaption of the software to the preclinical MR system was successful,
resulting in simulated basis sets that could be well fitted to the spectra
measured in the validation which, in turn, resulted in accurate determination
of metabolite concentrations in the phantom. The in vivo experiments resulted
in metabolic profiles of the cancer model and the healthy mouse brain that
were in agreement with what has been found in previous studies. The method
developed in this work will thus enable metabolite quantification of existing
and future MR spectroscopy studies at the preclinical MR facility at the
University of Gothenburg. | sv |
