Results 131 to 140 of about 129,335 (167)

Pulse-width modulation for simultaneous concomitant field compensation and diffusion weighting in double diffusion encoding

ISMRM Annual Meeting, 2023
Intravoxel dephasing caused by Maxwell or concomitant fields can lead to image artifacts as signal voids or falsify the quantitation. In this study, a framework for compensation of concomitant field effects for double diffusion encoding sequences with single pairs of bipolar gradients on each axis is presented.
Julian Rauch, Frederik Laun, Dominik Ludwig, Maxim Zaitsev, Mark Ladd, Peter Bachert, Tristan Kuder   +6 more
openaire   +1 more source

Isolating restriction and exchange in gray matter using double and single diffusion encodings with equal diffusion weighting

ISMRM Annual Meeting, 2023
The diffusion MR signal in complex tissue such as gray matter exhibits non-Gaussian signal attenuation due to exchange and restrictions. Existing signal models typically ignore one or both effects by assuming Gaussian diffusion or negligible exchange. We propose a more rigorous signal model that incorporates both effects.
Teddy Cai, Nathan Williamson, Rea Ravin, Peter Basser   +3 more
openaire   +1 more source

Detection of microscopic diffusion anisotropy in human cortical gray matter in vivo with double diffusion encoding

Magnetic Resonance in Medicine, 2018
PurposeTo detect microscopic diffusion anisotropy in human cortical gray matter in vivo with double diffusion encoding experiments.MethodsDouble diffusion encoding experiments were performed on a 3 T whole‐body MR system using echo‐planar imaging. Angular double diffusion encoding measurements were acquired with 8 × 8 and 12 × 12 planar direction ...
Marco Lawrenz, Jürgen Finsterbusch
openaire   +2 more sources

Stimulated echo double diffusion encoded imaging of closed pores: Influence and removal of unbalanced terms

Physical Review E, 2019
Nuclear magnetic resonance (NMR) diffusion pore imaging has been proposed to study the shape of arbitrary closed pores filled with an NMR-detectable medium by use of nonclassical diffusion encoding schemes. Potential applications can be found in biomedical imaging and porous media research.
Kerstin, Demberg, Frederik Bernd, Laun, Peter, Bachert, Mark Edward, Ladd, Tristan Anselm, Kuder   +4 more
openaire   +2 more sources

Detecting dendritic spine density with double diffusion encoding magnetic resonance spectroscopy

ISMRM Annual Meeting
Motivation: Studies shown that single diffusion encoding measurements of metabolites diffusion may be sensitive to dendritic spines, while Double Diffusion Encoding (DDE) increases sensitivity to microstructure features like dendritic length. Goal(s): Investigate whether DDE measurements can be sensitive to spine density and used to map it in-vivo ...
Maëliss Jallais, Sophie Malaquin, Kadir Simsek, Julien Valette, Marco Palombo   +4 more
openaire   +1 more source

Monte Carlo Simulation of Multiparameter Effects in Double Diffusion Encoding MRI

ISMRM Annual Meeting
Motivation: Double Diffusion Encoding (DDE) MRI presents a promising approach for probing tissue microstructure, yet its clinical utility is challenged by the complexity of multiparameter optimization. Goal(s): This study aims to investigate the effects of DDE encoding parameters and tissue microstructure and geometry on the diffusion signal. Approach:
Rachawadee Trinate, David Berry, Jean-Philippe Galons, Vitaly Galinsky, Lawrence Frank, Elizabeth Hutchinson   +5 more
openaire   +1 more source

Unifying b-tensor encoding with compartmental-exchange: A novel analysis framework applied to double diffusion encoding

ISMRM Annual Meeting
Motivation: Microstructure imaging with diffusion MRI is substantially improved by going beyond single diffusion encoding, but the methods using such data are divergent. In particular, theories unifying b-tensor encoding and water exchange are lacking.
Markus Nilsson, Arthur Chakwizira, Filip Szczepankiewicz, Samo Lasic, Carl-Fredrik Westin   +4 more
openaire   +1 more source

Quantifying the Diffusion of a Fluid through Membranes by Double Phase Encoded Remote Detection Magnetic Resonance Imaging

The Journal of Physical Chemistry B, 2007
We demonstrate that a position correlation magnetic resonance imaging (MRI) experiment based on two phase encoding steps separated by a delay can be used for quantifying diffusion across a membrane. This method is noninvasive, and no tracer substance or concentration gradient across the membrane is required.
Ville-Veikko, Telkki, Christian, Hilty, Sandra, Garcia, Elad, Harel, Alexander, Pines   +4 more
openaire   +2 more sources

Quantification of exchange in the mouse brain using double diffusion encodings with fixed total diffusion-weighting

ISMRM Annual Meeting
Motivation: Exchange is an important effect in diffusion MR of the brain but remains difficult to quantify using conventional methods and signal models due to parameter degeneracy. Goal(s): To develop and demonstrate robust measurement of exchange in the mouse brain.
Teddy Cai, Nathan Williamson, Peter Basser, Mohamed Tachrount, Karla Miller   +4 more
openaire   +1 more source

Compensation of concomitant field effects in double diffusion encoding by means of added oscillating gradients

Magnetic Resonance Imaging
Maxwell or concomitant fields imprint additional phases on the transverse magnetization. This concomitant phase may cause severe image artifacts like signal voids or distort the quantitative parameters due to the induced intravoxel dephasing. In particular, double diffusion encoding (DDE) schemes with two pairs of bipolar diffusion-weighting gradients ...
Julian, Rauch, Frederik B, Laun, Peter, Bachert, Mark E, Ladd, Tristan A, Kuder   +4 more
openaire   +2 more sources