Showing papers in "Magnetic Resonance Imaging in 2005"

TL;DR: This review examines the response of the magnetic resonance visible iron in tissue that produces signal changes in both magnitude and phase images that seem to correlate with brain iron content, but still have not been successfully exploited to accurately and precisely quantify brain iron.

TL;DR: In this paper, a magnetic resonance imaging (MRI) system is presented for highly precisely detecting and compensating body motions within a short processing time during radial scanning, which includes a control unit that applies radiofrequency magnetic fields and magnetic field gradients to a subject lying down in a static magnetic field and detects magnetic resonance signals generated from the subject.

TL;DR: The in vivo results show a good separation between breast cancer and benign fibroadenoma utilizing the shear modulus and the results as obtained for theShear viscosity do not indicate to be useful for separating benign from malignant lesions.

TL;DR: A method is presented that compares the tissues of interest (TOI) curve shape to that of a reference region (RR), thereby eliminating the need for direct AIF measurement and allowing for quantitative assessment of tissue properties without having to obtain high temporal resolution images to characterize an AIF.

TL;DR: In this article, the authors used ultrashort pulse sequence echo times (TEs) to detect signal from cortical bone in human subjects and use this signal to characterise this tissue.

TL;DR: The order within proton pairs in organic molecules, resulting from hydrogenation with parahydrogen, can be transferred in great part to nearby carbon 13 spins through adequate field manipulations, and the molecules with hyperpolarized 13C thus obtained can be used as new contrast agents of high efficiency in MRI.

TL;DR: High-resolution MRI provides a noninvasive tool for monitoring the development of cartilage repair tissue in MACI over time and helps to differentiate abnormal repair tissue from a normal maturation process.

TL;DR: The VLF fluctuation and temporal synchrony of the BOLD signal become increased after sedation in functional brain regions, and the fast Fourier transformation power spectral baseline fit parameters of theBOLD signal were also found to change significantly.

TL;DR: This work statistically validates the results of FD analysis on a set of 80 real MR and CT images and finds that the tumor region offers a statistically significant lower FD compared with that of the nontumor area for most of the FD algorithms studied.

TL;DR: The design, construction and use of a field-cycled proton-electron double-resonance imaging (FC-PEDRI) system for the detection and imaging of free radicals and the distribution of stable free radical contrast agents in phantoms and in anesthetized rats are described.

TL;DR: MRI was used to measure the water content distribution in a polymer electrolyte membrane under fuel cell operation with and without a supply of liquid water and showed that MRI is a promising method to investigate the distribution of water in the membrane of a fuel cell under operating conditions.

TL;DR: Reductions in MRI-induced heating at 1.5 T resulting from a simple design change to coiled wires were investigated and have important implications for MRI- induced heating of leads used for medical implants.

TL;DR: It was shown that the T1-weighted dynamic contrast-enhanced imaging technique noninvasively provides information for separating different tumor types and characterizing their microenvironment.

TL;DR: RF-metal interaction effects were investigated systematically at B0=0.2, 1.5 and 3 T analyzing correlated image artifacts for copper wires, and for following instruments and implants made of titanium or nitinol: biopsy needles, hip prostheses, vascular stents and aneurysm clips.

TL;DR: Results are presented of a multinuclear nuclear magnetic resonance study on the fixation of chloride in the hydration products and the characterization of new phases potentially appearing due to chloride ingress.

TL;DR: High b-value diffusion imaging can detect tissue damage in the NAWM of MS patients and provides additional information which is clinically relevant for detection of tissue damage not seen in conventional imaging techniques.

TL;DR: In this study, the effect of different analysis methods upon signal detection efficacy, as assessed by receiver operator characteristic (ROC) measures, was examined for perfusion fMRI data.

TL;DR: Results showed that temperature elevations associated with clinical sequences were within an acceptable physiologically safe range for the MR conditions used in this evaluation, especially for the use of relatively low SAR levels.

TL;DR: A number of new applications of unilateral NMR in materials science are reviewed, including the state assessment of polyethylene pipes, the characterization of wood, the in situ evaluation of stone conservation treatment, high-resolution profiling of rubber tubes and 2-D imaging for defect analysis in rubber products.

TL;DR: Findings suggest that subependymal/subpial LA and subcortical LA may be separate manifestations of a single underlying pulse-wave encephalopathy.

TL;DR: Respiratory-triggered MRCP using a T2w TSE sequence with PACE significantly improves image quality and may be included into the routine MRCPs sequence protocol.

TL;DR: An investigation employing phantom breast tissue composed of various combinations of chicken breast (to represent parenchyma) and cooking fats was carried out to elucidate the factors that influence MRI T1 histograms.

TL;DR: A quantitative analysis of NMR proton relaxation in hen egg albumen and yolk is undertaken and the results suggest that the low-field T1 is the best relaxation time indicator of albumen quality.

TL;DR: The crystallization of salts in porous materials with well-defined pore sizes is studied to show a metastable crystal phase and an increase in solubility with a decrease in pore size, which seems to be related to an increase of the stress generated by a crystal on the pore wall.

TL;DR: The 8-T MRI visualized infarcts and microvasculature with high resolution, revealing infarCTs and vascular pathologies that were not apparent at 1.5 T and is feasible for stroke imaging.

TL;DR: The reproducibility of areas of activity identified with both SEEP and BOLD contrast is assessed in duplicate experiments in healthy volunteers, and these observations provide further support for the existence of a non-BOLD-contrast mechanism for fMRI, based on changes in extravascular spin density.

TL;DR: In this paper, a fast spin echo two-point Dixon (fast 2PD) technique was developed for efficient T2-weighted imaging with uniform water and fat separation, which uses an improved and robust region-growing scheme for phase correction.

TL;DR: Diffusion-weighted relaxation protocols for two-dimensional diffusion/relaxation time (D, T(2)) distributions and their application to fluid-saturated sedimentary rocks at low fields typical of oil-well logging tools are reviewed.

TL;DR: It is demonstrated that Gd-DTPA had no significant impact on the ADC as measured in a 7-T animal system, demonstrating that diffusion-weighted imaging is performed without contrast agents.

TL;DR: The linear (or nonlinear) responses to neuronal activation of three hemodynamic parameters based primarily on changes of cerebral blood volume, blood flow and blood oxygenation were investigated by testing these hemodynamic responses' additivity property, suggesting that caution should be taken in the interpretation of hemodynamic-based signals in fMRI.