@conference {1325, title = {Correction of Gibbs ringing in diffusion MRI data using total variation regularization}, year = {2012}, month = {January}, pages = {99}, keywords = {MRI distortion artefacts}, author = {Daniele Perrone and Jan Aelterman and Maryna Kudzinava and Jan Sijbers and Aleksandra Pizurica and Wilfried Philips and Alexander Leemans} } @conference {Kudzinava_2011_ESMRMB, title = {Denoising of DKI images: effect on feasibility and accuracy of kurtosis parameters}, year = {2011}, month = {October}, pages = {236}, address = {Leipzig, Germany}, abstract = {Diffusion Kurtosis Imaging (DKI) is a new MRI technique, which quantifies non-Gaussianity of water diffusion. DKI requires high b-values, resulting in a low SNR of acquired diffusion weighted images (DWIs). Generally, kurtosis tensors are estimated from these DWIs using Weighted Least Squares (WLS) or Maximum Likelihood (ML) methods. In this work, we apply the Restricted Local Maximum Likelihood (RLML) denoising algorithm to remove noise from DWIs prior to WLS estimation. Then, we compare the RLML+WLS approach to the WLS and ML methods in terms of feasibility, that is the percentage of estimated tensors that satisfy certain DKI model constraints; and in terms of accuracy of calculated values of Mean Kurtosis.}, keywords = {denoising, diffusion kurtosis imaging, maximum likelihood estimation}, author = {Maryna Kudzinava and Jeny Rajan and Jan Sijbers} } @conference {Kudzinava_2011_WMSG, title = {Diffusion and kurtosis parameters in white matter of premature newborns}, year = {2011}, month = {August}, pages = {21}, address = {Reykjavik, Iceland}, abstract = {Diffusion Tensor Imaging (DTI) is often used to study brain maturation processes and white matter (WM) injuries in premature newborns. However, DTI assumes that water diffusion in biological tissues is free. In reality, there is always structural hindrance in WM, which only increases with age due to myelination. Diffusional Kurtosis Imaging (DKI) relaxes the assumption of free diffusion and allows estimation of conventional diffusion parameters plus new kurtosis measures, which are related to tissue complexity. In this work, we present and discuss the first statistics of DKI parameters in WM of two prematurely born infants.}, keywords = {anisotropy, diffusion, kurtosis, premature newborns, white matter}, author = {Maryna Kudzinava and A. Plaisier and J. Dudink and Jan Sijbers} } @conference {1307, title = {Distortion correction of DKI data: affine approach}, year = {2011}, month = {December}, abstract = {In this work, the performance of FMRIB{\textquoteright}s Linear Registration Tool (FLIRT) is evaluated with respect to motion and distortion correction of diffusion kurtosis imaging (DKI) data. FLIRT is tested on two DKI datasets heavily distorted by motion and eddy currents artefacts. Six different criteria are used for evaluation. Our results show that distortion correction using FLIRT substantially improves the original data. However, being an affine registration tool, FLIRT cannot cope with the amount of non-linear distortion present in DKI datasets. Hence, we conclude that, for correction of DKI data, non-linear registration techniques are more suitable.}, keywords = {medical imaging}, author = {Maryna Kudzinava and Alexander Leemans and Wilfried Philips and Daniele Perrone and Jan Aelterman and J. Dudink and Jan Sijbers} } @conference {1308, title = {Gibbs artifact suppression for DT-MRI data}, year = {2011}, month = {December}, keywords = {medical imaging}, author = {Daniele Perrone and Jan Aelterman and Maryna Kudzinava and Jan Sijbers and Aleksandra Pizurica and Wilfried Philips and Alexander Leemans} } @inproceedings {Kudzinava_2011_ISBI, title = {Optimized Workflow for Diffusion Kurtosis Imaging of Newborns}, booktitle = {ISBI, 8th IEEE International Symposium on Biomedical Imaging: From Nano to Macro}, year = {2011}, month = {April}, pages = {922-926}, address = {Chicago, USA}, abstract = {Diffusional kurtosis imaging (DKI) is a recently proposed extension of the conventional DTI model. It has been shown to offer more sensitive characterization of neural tissues than DTI. So far, DKI has only been applied to adult human and small animal studies, but not yet to human newborns. In this work, we present an optimized workflow for the acquisition and processing of DKI images of newborns. First, optimal set of diffusion weighting gradients for DKI studies of newborn subjects is proposed. Optimized gradients allow to estimate DKI parameters with the highest precision. Next, preprocessing and segmentation of the DKI data is considered, including motion correction, eddy currents suppression, intensity modulation and gradients reorientation. Finally, statistics of estimated diffusion and kurtosis parameters for different neonatal brain tissues are calculated.}, keywords = {diffusion and kurtosis parameters, DKI, motion correction, newborns, optimal gradients, precision}, doi = {10.1109/ISBI.2011.5872554}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=5872554}, author = {Maryna Kudzinava and Dirk H J Poot and A. Plaisier and Jan Sijbers} }