Monitoring the early responses of tumours to treatment is a crucial element in guiding therapy and increasing patient survival. To achieve this, we are using magnetic resonance imaging (MRI), which can provide detailed physiological information with relatively high temporal and spatial resolution. In combination with the dynamic nuclear polarisation (DNP) technique, high signal-to-noise is obtained, resulting in a powerful tool for in vivo 13C metabolic imaging. However, detection of hyperpolarised substrates is limited to a few seconds due to the exponential decay of the polarisation with the longitudinal relaxation time constant T1. This work aimed to improve the combination of hyperpolarisation and metabolic NMR/ MRI by extending the observation timescale of the technique. Working with quantum mechanical properties of the detected substrates, long lifetimes might be accessible by using the nuclear singlet configuration of two coupled nuclei. The singlet state is immune to intramolecular dipole-dipole relaxation processes, which is one of the main sources of signal decay in MRI. In favourable situations, the singlet relaxation time constant can be much longer than T1, so transfer of the polarisation into the singlet state may allow one to extend the usable time period of the nuclear hyperpolarisation. Here we studied the relaxation of hyperpolarised metabolites, including those found in the TCA cycle, and examined the possibility of extending their observation timescale by storing the polarisation in the long-lived singlet state. The polarisation remains in this state until it is eventually required for imaging. We also investigate how one may track polarised metabolites after injection into a subject due to the transfer of polarisation to the solvent by Overhauser cross-relaxation, so that the 13C polarisation remains untouched until imaging is required. In this way we should be able to interrogate slower metabolic processes than have been examined hitherto using hyperpolarised 13C MRS, and better understand metabolic changes induced in tumours by treatment.

This thesis focuses on cardiac imaging and quantification of T1 relaxation time in rat hearts. Its main focus is to investigate available methods for such quantification and their application in the development of quantification tools. The large impact is given to methods of acquisition synchronization, mainly with respect to cardiac motion and breathing using retrospective gating, where the navigator signal is obtained solely from the acquired data, so without any external equipment such as the ECG or respiratory sensors. This paper takes into account situations where steady-state has been reached and also those where it has not, by means of contrast agent injection or by inversion pulses.

The aim of the thesis was familiarity of segmentation methods for automatic segmentation of MR images, using multiparametrical display. The theoretical part focuses on the description of methods of segmentation techniques. In the practical part are implemented K-means and level-set method. The methods are tested on the images of the brain obtained by different sequences (T1, T1c, T2, FLAIR). Segmentation methods are implemented in the program MATLAB. Implemented segmentation accuracy is demonstrated on data which there are reports reference results. Evaluation methods is performed using different classifiers decision. The K-means method is tested different metrics and different combinations of the input image. Finally, both methods are compared with one another and visually evaluated against the reference image.

This thesis deals with the cartilage imaging using magnetic resonance. At first, there is mentioned physical principle of the magnetic resonance phenomenon and the most commonly used excitation sequences, followed by the description of the 9.4 T MR imaging system Bruker BioSpec 94/30 USR, which was used for measurement in the practical part. The next part is dedicated to the composition of cartilages and describes the temporomandibular joint, due to its suitability as an object for cartilage imaging. The series of MR scans of temporomandibular joint were taken with different acquisition parameters and evaluated by program designed through the MATLAB software. The program can be used for viewing scanned images, evaluating their contrast and determining the T1 relaxation time of the tissues by creating T1 maps.

Background: Type 2 diabetes mellitus is a metabolic disorder characterized by the rise of fasting plasma glucose from its normal range (≥125mg/dl). It is marked by insufficient production of insulin from pancreatic β-cells as a result of failed compensation due to insulin resistance. Several treatments are available for the disorder, which mainly focus on improving the sensitivity of insulin in different body tissues. Recently, probiotics were suggested as candidate treatments for type 2 diabetes and for extending lifespan as well. This experiment aims to investigate such claims using Drosophila melanogaster as a disease model.   Results: Other than the observed low average weights in treated larva samples, probiotics did not show any other significant results in affecting the length, glucose, glycogen, and trehalose levels (One-Way ANOVA and Kruskal-Wallis, p>0.05). Real-time PCR was only carried out once. Thus, no statistical tests were reliable enough to analyse the data obtained. The longevity study, on the other hand, did show significance (Log-rank (Mantel-Cox) test and Gehan-Breslow-Wilcoxon test, p<0.0001), as the probiotic Bifidobacterium lactis extended the lifespan of adult flies feeding on a high sugar diet significantly when compared to the control ones feeding on only high sugar diet without probiotics.   Conclusion: Except for weight measurements, none of the other results was reliable enough to make a concrete conclusion on whether the treatments indeed worked in reversing type 2 diabetes symptoms or not. Real-time PCR results did show some effects of some of the treatments at different developmental stages. However, unless Real-time PCR is repeated at least once using the same protocol, no deduction can be made. Additionally, the data obtained hint that the dosage used (0.025 g) was too high for larvae and adult flies and might have caused malnutrition by blocking their midgut and decreasing food absorption. Hence, false significant or non-significant results were acquired instead.   Further studies are required using a much lower probiotic dosage if Drosophila is used as a disease model. Although, other models such as mice or rats are recommended in this case, in order to reach a solid conclusion about the effectiveness of probiotics in treating type 2 diabetes mellitus. Baring these thoughts in mind and based on the results of this experiment, the null hypothesis indicating that there is no significant relationship between the use of probiotics and reversing type 2 diabetes mellitus symptoms is therefore accepted.

In calling for the deployment of high-capacity telecommunications infrastructures, the Clinton Administration is relying on market forces to drive demand toward self-sustaining development. There is little doubt that many firms will embrace the new telecommunications services for a variety of reasons including market differentiation, vertical market integration, and other organization-specific factors. However, there is little evidence at the firm level that adopting the use of increased-capacity telecommunications technologies is associated with improvements in firm profitability. This study seeks to identify the presence of impacts on firm income that can be associated with the adoption of T1 telecommunications services.

This project revolves around the measurement of T1 and T2 relaxation times in the ratbrain, in a multi-center way. That is to say, elaborate an efficient protocol to calculate highresolution 3D map of the brain. This protocol should be applied in different centers andreturn similar results. Finally, procedures should be defined to ease the collaborationbetween the different centers. The first step consisted in in vitro experiments, in whichdifferent sequences were tested. It resulted that the MDEFT sequence with inversionpreparation (MPRAGE) gives the best results in the shortest time for T1. For T2, theMSME sequence was chosen. The next step moved on in vivo experiments on three rats inorder to get used to manipulating living animals and make new adjustments. As thephysiology is not the same on in vitro and in vivo experiments, some parameters had to beslightly adapted. Once the final 2h-protocol was established, it was tested on a populationof ten rats. Experiments were made at the GIN and CRMBM. Different fitting pipelineswere tried (GIN, CRMBM, MIRCEN). The brain was segmented into different regions. Itresulted that the GIN and CRMBM pipelines return the same T1 values using the differentdatasets. The MIRCEN pipeline under-estimates by 200 ms. The three pipelines return similar T2 values. The GIN and CRMBM datasets provide comparable T1 values, but theGIN center presents slightly higher T2 values. Regarding the multi-center collaboration,the different pipelines were ported to the VIP platform so that the scientific community caneasily reuse them.

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