List of Papers This thesis is based on the following papers, which are referred to in the text by their Roman numerals. Abbreviations ADC Apparent diffusion coefficient AIF Arterial input function ASL Arterial spin labeling CBF Cerebral blood flow CBV Cerebral blood volume CPB Cardio pulmonary bypass DSC-MRI Dynamic susceptibility contrast MRI MRI Magnetic resonance imaging MRS Magnetic resonan...

Magnetic nanoparticles (NPs) are increasingly being considered for use in biomedical applications such as biosensors, imaging contrast agents and drug delivery vehicles. In a biological fluid, proteins associate in a preferential manner with NPs. The small sizes and high curvature angles of NPs influence the types and amounts of proteins present on their surfaces. This differential display of p...

Introduction: Early diagnosis of ovarian cancer is difficult due to the absence of reliable biological markers. The design of tumor specific contrast agents will facilitate detection of ovarian cancer at an early stage. The Tumor Endothelial Marker (TEM1) is a protein selectively expressed on the surface of ovarian cancer vasculature. A high affinity antibody (scFv-CM6) specific for TEM1 has be...

We describe the synthesis, characterization and application as contrast agents in magnetic resonance imaging of a novel type of magnetic nanoparticle based on Gd-Si oxide, which presents high Gd3+ atom density. For this purpose, we have used a Prussian Blue analogue as the sacrificial template by reacting with soluble silicate, obtaining particles with nanorod morphology and of small size (75 n...

A. Water Exchange 2326 B. Proton Exchange 2327 C. Electronic Relaxation 2327 D. Relaxivity 2331 E. Outerand Second-Sphere Relaxivity 2334 F. Methods of Improving Relaxivity 2336 V. Macromolecular Conjugates 2336 A. Introduction 2336 B. General Conjugation Methods 2336 C. Synthetic Linear Polymers 2336 D. Synthetic Dendrimer-Based Agents 2338 E. Naturally Occurring Polymers (Proteins, Polysaccha...

The factors limiting the relaxivity (r) of MRI contrast agents based on small (∼2.0 nm) gold nanoparticles functionalised with paramagnetic chelates were explored using EPR spectroscopy. The EPR analysis suggested that nanoparticle-attached chelates exhibit relatively high tumbling rates which restrict their relaxivity. Two different strategies were employed in order to test this hypothesis and...

The synthesis and relaxivity properties of a new dendrimeric Gd chelate, Gd-TREN-bisHOPO-TAM-Asp-Asp2-12OH, are presented. The macromolecule demonstrates improved water solubility due to its 12 terminal hydroxyl groups and improved relaxivity due to its optimal water exchange rate and slower molecular tumbling. Unprecedented high relaxivity (r1p = 18 mM-1 s-1) is observed at high magnetic field...

NMR responses are commonly used in reservoir characterization to estimate pore-size information, formation permeability, as well as fluid content and type. Difficulties arise in the interpretation of NMR response as an estimator of permeability due to internal gradients, diffusion coupling, surface-relaxivity heterogeneity, and a possible breakdown of correlations between pore and constriction ...

Introduction: Targeted and smart molecular contrast agents have made it possible to detect events in the molecular scale in vivo (1). While many iron oxide based contrast agents with per ion T2 relaxivity of ~100mMs allow the detection of nM concentrations, common lanthanide chelates such as Gd-DTPA, with T1 relaxivity ~5mMs , require μM-mM concentrations, making the study of molecular events d...

Novel gadolinium complexes (KMR-series: KMR-K and KMR-Mg), which have a bis-15-crown-5 ether or a charged beta-diketone structure as a recognition site, have been designed, synthesized and applied for the detection of K(+) or of Mg(2+) and Ca(2+) using MRI or NMR techniques. The measurements are based on the modulation of the longitudinal relaxation time (T(1)) of water protons in proximity of ...