Joint multi-field T quantification for fast field-cycling MRI.

Purpose: Recent developments in hardware design enable the use of fast field-cycling (FFC) techniques in MRI to exploit the different relaxation rates at very low field strength, achieving novel contrast. The method opens new avenues for in vivo characterizations of pathologies but at the expense of longer acquisition times. To mitigate this, we propose a model-based reconstruction method that fully exploits the high information redundancy offered by FFC methods.

Multi-quantum quadrupole relaxation enhancement effects in Bi compounds.

H spin-lattice nuclear magnetic resonance relaxation experiments have been performed for triphenylbismuth dichloride (CHBiCl) and phenylbismuth dichloride (CHBiCl) in powder. The frequency range of 20-128 MHz has been covered. Due to H-Bi dipole-dipole interactions, a rich set of pronounced Quadrupole Relaxation Enhancement (QRE) peaks (quadrupole peaks) has been observed.

Estimation of the magnitude of quadrupole relaxation enhancement in the context of magnetic resonance imaging contrast.

Magnetic Resonance Imaging (MRI) is one of the most powerful diagnostic tools providing maps of H relaxation times of human bodies. The method needs, however, a contrast mechanism to enlarge the difference in the relaxation times between healthy and pathological tissues. In this work, we discuss the potential of a novel contrast mechanism for MRI based on Quadrupole Relaxation Enhancement (QRE) and estimate the achievable value of QRE under the most favorable conditions.

High-Field Detection of Biomarkers with Fast Field-Cycling MRI: The Example of Zinc Sensing.

Many smart magnetic resonance imaging (MRI) probes provide response to a biomarker based on modulation of their rotational correlation time. The magnitude of such MRI signal changes is highly dependent on the magnetic field and the response decreases dramatically at high fields (>2 T). To overcome the loss of efficiency of responsive probes at high field, with fast-field cycling magnetic resonance imaging (FFC-MRI) we exploit field-dependent information rather than the absolute difference in the relaxation rate measured in the absence and in the presence of the biomarker at a given imaging field.

Detection and Elimination of Signal Errors Due to Unintentional Movements in Biomedical Magnetic Induction Tomography Spectroscopy (MITS).

In biomedical MITS, slight unintentional movements of the patient during measurement can contaminate the aimed images to a great extent. This study deals with measurement optimization in biomedical MITS through the detection of these unpredictable movements during measurement and the elimination of the resulting movement artefacts in the images to be reconstructed after measurement. The proposed detection and elimination (D&E) methodology requires marking the surface of the object under investigation with specific electromagnetically perturbing markers during multi-frame measurements.