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Cerebral Blood Flow Increases Across Early Childhood [article]

Dmitrii Paniukov, R. Marc Lebel, Gerald Giesbrecht, Catherine Lebel
2019 bioRxiv   pre-print
AbstractAdequate cerebral blood flow (CBF) is essential to proper brain development and function. Detailed characterization of CBF developmental trajectories will lead to better understanding of the development of cognitive, motor, and sensory functions, as well as behaviour in children. Previous studies have shown CBF increases during infancy and decreases during adolescence; however, the trajectories during childhood, and in particular the timing of peak CBF, remain unclear. Here, we used
more » ... rial spin labeling to map age-related changes of CBF across a large longitudinal sample that included 279 scans on 96 participants (46 girls and 50 boys) aged 2-7 years. CBF maps were analyzed using hierarchical linear regression for every voxel inside the grey matter mask, controlling for multiple comparisons. The results revealed a significant positive linear association between CBF and age in distributed brain regions including prefrontal, temporal, parietal, and occipital cortex, and in the cerebellum. There were no differences in developmental trajectories between males and females. Our findings suggest that CBF continues to increase at least until the age of 7 years, likely supporting the ongoing improvements in behaviour, cognition, motor, and sensory functions of the children in early childhood.Highlights*We mapped cerebral blood flow development longitudinally in 96 typically developing children aged 2-7 years*Cerebral blood flow increased over the full age range*No significant differences between males and females were foundConflicting of InterestR.M.L. is an employee of GE.
doi:10.1101/587139 fatcat:4tkd7wjn4zfkjokm4nb6s6ah3u

Multimodal principal component analysis to identify major features of white matter structure and links to reading [article]

Bryce Landon Geeraert, Maxime Chamberland, R. Marc Lebel, Catherine Lebel
2020 bioRxiv   pre-print
Geeraert B, Reynolds J, Lebel C. Diffusion imaging perspectives on brain development in childhood and adolescence.  ...  Statistical Analysis All statistical analysis was performed in R version 3.6.1 [50] .  ... 
doi:10.1101/2020.05.04.076521 fatcat:4hbja5wib5ckvbuaxkzy53ldqe

Performance characterization of a novel deep learning-based MR image reconstruction pipeline [article]

R. Marc Lebel
2020 arXiv   pre-print
., 2019; Souza, Lebel, & Frayne, 2019; Zhu, Liu, Cauley, Rosen, & Rosen, 2018) .  ...  Methods AIRä Recon DL The AIRä Recon DL reconstruction pipeline takes raw k-space data as its input and generates high fidelity images as its output (Argentieri et al., 2019; Bash, Thomas, Fund, Lebel  ... 
arXiv:2008.06559v1 fatcat:r7qi2oii4vaq5ciuwddlk5zdt4

Multimodal principal component analysis to identify major features of white matter structure and links to reading

Bryce L. Geeraert, Maxime Chamberland, R. Marc Lebel, Catherine Lebel, Pew-Thian Yap
2020 PLoS ONE  
All analysis was conducted in R version 3.6.1 [50] .  ...  RM, Lebel C (2020) Multimodal principal component analysis to identify major features of white matter structure and links to reading.  ... 
doi:10.1371/journal.pone.0233244 pmid:32797080 fatcat:se226545lvfghme2i7smkbxvvm

Research Highlights: Highlights from the latest articles in imaging

R Marc Lebel
2012 Imaging in Medicine  
doi:10.2217/iim.12.8 fatcat:ix2it43yn5glrcifknkonk66xq

Tracer Kinetic Models as Temporal Constraints during DCE-MRI reconstruction [article]

Sajan Goud Lingala, Yi Guo, R. Marc Lebel, Yinghua Zhu, Yannick Bliesener, Meng Law, Krishna S. Nayak
2017 arXiv   pre-print
12 brain tumor in- vivo 3T datasets at (R=20-40).  ...  In-vivo experiments demonstrated reduced bias and uncertainty in kinetic mapping with the proposed approach compared to tFD at R>=20.  ...  Figure 9 : Bland-Altman plots of a) the difference between estimated K trans (at R=20, R=40) and reference K trans ; b) the difference between estimated v p (at R=20, R=40) and reference v p ; for the  ... 
arXiv:1707.07569v1 fatcat:vbwj4c3sg5hwdiik4mmf7qveri

Dual-domain Cascade of U-nets for Multi-channel Magnetic Resonance Image Reconstruction [article]

Roberto Souza, Mariana Bento, Nikita Nogovitsyn, Kevin J. Chung, R. Marc Lebel, Richard Frayne
2019 arXiv   pre-print
R is the reciprocal of the fraction of k-space that was sampled. In this work we tested R = 4 and R = 8. This resulted in a total of 24 trained models.  ...  The post-hoc testing indicated that WW-net IKIK had the overall best metrics for both R = 4 and R = 8.  ... 
arXiv:1911.01458v1 fatcat:ypjko2g5qrf63lqsnkrb4witau

Sparse precontrast T 1 mapping for high‐resolution whole‐brain DCE‐MRI

Zhibo Zhu, R. Marc Lebel, Yannick Bliesener, Jay Acharya, Richard Frayne, Krishna S. Nayak
2021 Magnetic Resonance in Medicine  
For R ≤ 10, T1 SD was <107.1 ms in WM (COV ~9.9%) and <240.9 ms in BT (COV ~12.1%). In the healthy subject, T1 bias was <30 ms for R ≤ 16. At R = 4, T1 SD was 171.4 ms (COV ~13.0%).  ...  T1 -mapping precision decreased with undersampling factor R, althoughwhereas bias remained small before a critical R.  ...  The vendor-provided 3D spoiled gradient echo sequence was modified to include sparse VFA sampling with R = 4 before sparse DCE-MRI, as described by Lebel et al. 21 The resulting T 1 maps were qualitatively  ... 
doi:10.1002/mrm.28849 pmid:34036658 fatcat:46u4suvmqnczjj6pdakvxl5pti

Multiband multi-echo imaging of simultaneous oxygenation and flow timeseries for resting state connectivity

Alexander D. Cohen, Andrew S. Nencka, R. Marc Lebel, Yang Wang, Xi-Nian Zuo
2017 PLoS ONE  
OPEN ACCESS Citation: Cohen AD, Nencka AS, Lebel RM, Wang Y (2017) Multiband multi-echo imaging of simultaneous oxygenation and flow timeseries for resting state connectivity.  ...  Connectivity maps are displayed for PCC, L/R motor cortex, L/R insula, and L/R hippocampus seeds.  ...  Connectivity maps are displayed for PCC, L/R motor cortex, L/R insula, and L/R hippocampus seeds.  ... 
doi:10.1371/journal.pone.0169253 pmid:28253268 pmcid:PMC5333818 fatcat:2lwxxhawgzdetma3u6ffggtlpi

A Hybrid, Dual Domain, Cascade of Convolutional Neural Networks for Magnetic Resonance Image Reconstruction

Roberto Souza, R. Marc Lebel, Richard Frayne
2019 International Conference on Medical Imaging with Deep Learning  
Deep-learning-based magnetic resonance (MR) imaging reconstruction techniques have the potential to accelerate MR image acquisition by reconstructing in real-time clinical quality images from k-spaces sampled at rates lower than specified by the Nyquist-Shannon sampling theorem, which is known as compressed sensing. In the past few years, several deep learning network architectures have been proposed for MR compressed sensing reconstruction. After examining the successful elements in these
more » ... rk architectures, we propose a hybrid frequency-/image-domain cascade of convolutional neural networks intercalated with data consistency layers that is trained end-to-end for compressed sensing reconstruction of MR images. We compare our method with five recently published deep learning-based methods using MR raw data. Our results indicate that our architecture improvements were statistically significant (Wilcoxon signed-rank test, p < 0.05). Visual assessment of the images reconstructed confirm that our method outputs images similar to the fully sampled reconstruction reference.
dblp:conf/midl/SouzaLF19 fatcat:sgddvb3dkbdaxk457b42y3ebly

Tracer Kinetic Models as Temporal Constraints during brain tumor DCE‐MRI reconstruction

Sajan Goud Lingala, Yi Guo, Yannick Bliesener, Yinghua Zhu, R. Marc Lebel, Meng Law, Krishna S. Nayak
2019 Medical Physics (Lancaster)  
Patient-specific AIF delays were estimated as described by Lebel et al. 54 Briefly, the k-space origin was frequently sampled, and plotted as a function of time.  ...  1 x;0 ð Þþc x;t ð Þr 1 ½ À Á 1 À cos a e ÀTR R 1 x;0 ð Þþc x;t ð Þr 1 ½ ð Þ þ s x; 0 ð ÞÀ M 0 x ð Þ sin a 1 À e ÀTR R 1 x;0 ð Þ ½ À Á 1 À cos a e ÀTR R 1 x;0 ð Þ ½ ð Þ " # ; (4) where r 1 is the contrast  ... 
doi:10.1002/mp.13885 pmid:31663134 pmcid:PMC6980286 fatcat:gzfpg6uvanfobaoqttqqfyfcfq

Cerebral Perfusion Changes in Post-Concussion Syndrome: A Prospective Controlled Cohort Study

Karen M. Barlow, Lorenzo D. Marcil, Deborah Dewey, Helen L. Carlson, Frank P. MacMaster, Brian L. Brooks, R. Marc Lebel
2017 Journal of Neurotrauma  
Post-injury symptom score could be predicted by pre-injury symptoms and CBF in presence of mTBI (adjusted R 2 = 0.424; p < 0.001).  ...  R square Adjusted R square df1 df2 Sig.  ...  Table 3 . 3 Regression Model Summary Predicting Neurocognition Index R R square Adjusted R square df1 df2 Sig.  ... 
doi:10.1089/neu.2016.4634 pmid:27554429 pmcid:PMC5333570 fatcat:sh2rj2gpkfg7bgmbhdt6b6kiim

Diffusion kurtosis and quantitative susceptibility mapping MRI are sensitive to structural abnormalities in amyotrophic lateral sclerosis

Thomas Welton, Jerome J. Maller, R. Marc Lebel, Ek T. Tan, Dominic B. Rowe, Stuart M. Grieve
2019 NeuroImage: Clinical  
= 0.25, p = .039), FA (r = −0.25, p = .045) and FAK (r = −0.34, p = .006).  ...  Disease severity For ALSFRS-R, the following variables had supra-threshold univariate relationships: ADC (r = −0.38, p = .097), AKC (r = 0.42, ALS, amyotrophic lateral sclerosis; ADC, apparent diffusion  ... 
doi:10.1016/j.nicl.2019.101953 pmid:31357149 pmcid:PMC6664242 fatcat:4jwlrp7hwbcctdqqu5cukfkg5y

Direct estimation of tracer-kinetic parameter maps from highly undersampled brain dynamic contrast enhanced MRI

Yi Guo, Sajan Goud Lingala, Yinghua Zhu, R. Marc Lebel, Krishna S. Nayak
2016 Magnetic Resonance in Medicine  
The approach is also applied to four prospectively R ¼ 30 undersampled whole-brain DCE-MRI data sets.  ...  Results: In the retrospective study, the proposed method performed statistically better than indirect method at R ! 80 for all 13 cases.  ...  Notably, Lebel et al (16) used a temporal high-pass filter and multiple spatial sparsity constraints to achieve an undersampling rate (R) of 36 Â and showed excellent quality of anatomical images in  ... 
doi:10.1002/mrm.26540 pmid:27859563 fatcat:cn3seq7vinaytoupfqgt3jt42y

Real-time 3D magnetic resonance imaging of the pharyngeal airway in sleep apnea

Yoon-Chul Kim, R. Marc Lebel, Ziyue Wu, Sally L. Davidson Ward, Michael C.K. Khoo, Krishna S. Nayak
2013 Magnetic Resonance in Medicine  
The k y and k z phase encodes were along anterior-posterior (A-P) and right-left (R-L) directions, respectively.  ...  Realtime movies of 3D airway dynamics were generated using an L1-SPIRiT reconstruction algorithm proposed by Lebel et al. (25) . Figure 3 shows the schematic of our reconstruction method.  ... 
doi:10.1002/mrm.24808 pmid:23788203 pmcid:PMC4159137 fatcat:boch4wsbd5fhbgmlp5p3d74rgq
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