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More accurate estimation of diffusion tensor parameters using diffusion kurtosis imaging University of Antwerp

Jelle Veraart, Dirk Poot, Wim Van Hecke, Ines Blockx, Anne Marie Van Der Linden, Marleen Verhoye, Jan Sijbers
With diffusion tensor imaging, the diffusion of water molecules through brain structures is quantified by parameters, which are estimated assuming monoexponential diffusion-weighted signal attenuation. The estimated diffusion parameters, however, depend on the diffusion weighting strength, the b-value, which hampers the interpretation and comparison of various diffusion tensor imaging studies. In this study, a likelihood ratio test is used to ...

Investigation of diffusion behavior in Cu–Sn solid state diffusion couples KU Leuven

Yuan Yuan, Yuanyuan Guan, Dajian Li, Nele Moelans
The diffusion behaviors and diffusion parameters of intermetallic compounds (IMCs) formed in Cu-Sn diffusion couples were investigated at the temperature range of 130 °C–200 °C. Interdiffusion coefficients of IMCs were calculated based on the measured composition profiles of the diffusion zones. Considering the wavy type of the diffusion layers and the narrow homogeneity range of the IMCs (Cu₃Sn and Cu₆Sn₅), the integrated method was performed ...

Investigation of the diffusion behavior in Sn-xAg-yCu/Cu solid state diffusion couples KU Leuven

Yuan Yuan, Dajian Li, Yuanyuan Guan, Hans J Seifert, Nele Moelans
The interfacial reactions and growth behavior of the Cu3Sn and Cu6Sn5 phases in Sn-3.0%Ag-0.5%Cu/Cu and Sn-3.5%Ag-0.7%Cu/Cu diffusion couples were investigated at 130 °C, 150 °C, 170 °C and 200 °C and compared with those in binary Sn/Cu diffusion couples using identical experimental conditions. The Ag solubility in the Cu3Sn and Cu6Sn5 phases was found to be quite small. The parabolic growth constants of Cu3Sn and Cu6Sn5 in Sn-xAg-yCu/Cu ...

Errors involved in the existing B-term expressions for the longitudinal diffusion in fully porous chromatographic media - Part II: Experimental data in packed columns and surface diffusion measurements Ghent University

K. Broeckhoven, D. Cabooter, Frédéric Lynen, Patrick Sandra, G. Desmet
Peak parking experiments have been performed on three RP-HPLC different columns, using two different components and a variable mobile phase composition. The aim of the study was to investigate whether the B-term diffusion expressions currently used in the literature (which are all Knox-type models) should be replaced by the effective diffusion expressions that have been developed in the frame of the effective medium theory (EMT). Although the ...

The design of anisotropic diffusion phantoms for the validation of diffusion weighted magnetic resonance imaging Ghent University

Els Fieremans, Yves De Deene, Steven Delputte, Mahir Ozdemir, Eric Achten, Ignace Lemahieu
Diffusion weighted magnetic resonance imaging offers a non-invasive tool to explore the three-dimensional structure of brain white matter in clinical practice. Anisotropic diffusion hardware phantoms are useful for the quantitative validation of this technique. This study provides guidelines on how to manufacture anisotropic fibre phantoms in a reproducible way and which fibre material to choose to obtain a good quality of the diffusion weighted ...

Numerical study on the importance of the turbulent inlet boundary condition and differential diffusion in a turbulent H 2 /N 2 /air jet diffusion flame KU Leuven Ghent University

A D’Ausilio, I Stankovic, Bart Merci
© 2018, © 2018 Taylor & Francis. This work concerns numerical simulations of the turbulent H 2 /N 2 /air jet diffusion flame (Meier et al., 1996a), using large eddy simulations with conditional moment closure as the combustion model. The study focuses on the impact of the Random Spots method (Kornev and Hassel, 2007), adopted to describe the turbulence at the inlet, on the flow field. Furthermore, the region where the contribution of ...

Automated correction of improperly rotated diffusion gradient orientations in diffusion weighted MRI University of Antwerp

Ben Jeurissen, Alexander Leemans, Jan Sijbers
Ensuring one is using the correct gradient orientations in a diffusion MRI study can be a challenging task. As different scanners, file formats and processing tools use different coordinate frame conventions, in practice, users can end up with improperly oriented gradient orientations. Using such wrongly oriented gradient orientations for subsequent diffusion parameter estimation will invalidate all rotationally variant parameters and fiber ...

Geography, structure, and evolution of diffusion and perfusion lesions in Diffusion and perfusion imaging Evaluation For Understanding Stroke Evolution (DEFUSE) KU Leuven

Jean-Marc Olivot, Michael Mlynash, Vincent Thijs, Archana Purushotham, Stephanie Kemp, Maarten G Lansberg, Lawrence Wechsler, Garry E Gold, Roland Bammer, Michael P Marks, et al.
BACKGROUND AND PURPOSE: The classical representation of acute ischemic lesions on MRI is a central diffusion-weighted imaging (DWI) lesion embedded in a perfusion-weighted imaging (PWI) lesion. We investigated spatial relationships between final infarcts and early DWI/PWI lesions before and after intravenous thrombolysis in the Diffusion and perfusion imaging Evaluation For Understanding Stroke Evolution (DEFUSE) study. METHODS: Baseline and ...

Evaluation of true diffusion, perfusion factor, and apparent diffusion coefficient in non-necrotic liver metastases and uncomplicated liver hemangiomas using black-blood echo planar imaging KU Leuven

Kenneth Coenegrachts, Joost Delanote, Leon ter Beek, Marc Haspeslagh, Sjandra Bipat, Jaap Stoker, Luc Steyaert, Hans Rigauts
PURPOSE: To assess the added value of true diffusion (D), perfusion factor (f) and apparent diffusion coefficient at low b-values (ADC(low)) for differentiation between liver metastases and hemangiomas based on respiratory-triggered high-resolution Black-Blood Single-Shot SpinEcho Echo Planar Imaging (BB SS SE-EPI). MATERIALS AND METHODS: Twenty-five patients suspected for malignant colorectal liver lesions were included in this study. A total ...