Intra‐ and inter‐site reproducibility of human brain single‐voxel proton MRS at 3 T

2019 ◽  
Vol 32 (6) ◽  
pp. e4083
Author(s):  
Carina Graf ◽  
Erin L. MacMillan ◽  
Eric Fu ◽  
Trudy Harris ◽  
Anthony Traboulsee ◽  
...  
Keyword(s):  
Human Brain ◽  
Proton Mrs ◽  
Single Voxel

Single-voxel proton MRS of the human brain at 1.5T and 3.0T

2001 ◽  
Vol 45 (5) ◽  
pp. 765-769 ◽  
Author(s):  
Peter B. Barker ◽  
David O. Hearshen ◽  
Michael D. Boska
Keyword(s):  
Human Brain ◽  
Proton Mrs ◽  
Single Voxel

Biexponential transverse relaxation (T2) of the proton MRS creatine resonance in human brain

2002 ◽  
Vol 47 (2) ◽  
pp. 232-238 ◽  
Author(s):  
Y. Ke ◽  
B.M. Cohen ◽  
S. Lowen ◽  
F. Hirashima ◽  
L. Nassar ◽  
...  
Keyword(s):  
Human Brain ◽  
Proton Mrs ◽  
Transverse Relaxation

A semi‐LASER, single‐voxel spectroscopic sequence with a minimal echo time of 20.1 ms in the human brain at 3 T

2020 ◽  
Vol 33 (9) ◽  
Author(s):  
Karl Landheer ◽  
Martin Gajdošík ◽  
Christoph Juchem
Keyword(s):  
Human Brain ◽  
Single Voxel ◽  
Echo Time

scholarly journals Regional Metabolite Concentrations in Aging Human Brain: Comparison of Short-TE Whole Brain MR Spectroscopic Imaging and Single Voxel Spectroscopy at 3T

2019 ◽  
Vol 30 (2) ◽  
pp. 251-261 ◽  
Author(s):  
Helen Maghsudi ◽  
Birte Schmitz ◽  
Andrew A. Maudsley ◽  
Sulaiman Sheriff ◽  
Paul Bronzlik ◽  
...  
Keyword(s):  
Human Brain ◽  
Spectroscopic Imaging ◽  
Whole Brain ◽  
Single Voxel ◽  
Metabolite Concentrations ◽  
Mr Spectroscopic Imaging

Automated single-voxel proton MRS: Technical development and multisite verification

1994 ◽  
Vol 31 (4) ◽  
pp. 365-373 ◽  
Author(s):  
Peter G. Webb ◽  
Napapon Sailasuta ◽  
Susan J. Kohler ◽  
Tom Raidy ◽  
Rex A. Moats ◽  
...  
Keyword(s):  
Technical Development ◽  
Proton Mrs ◽  
Single Voxel

scholarly journals Prevalence of white matter pathways coming into a single diffusion MRI voxel orientation: the bottleneck issue in tractography

2021 ◽  
Author(s):  
Kurt Schilling ◽  
Chantal M.W. Tax ◽  
Francois M.W. Rheault ◽  
Bennett A Landman ◽  
Adam W Anderson ◽  
...  
Keyword(s):  
White Matter ◽  
Human Brain ◽  
Diffusion Mri ◽  
Brain Connectivity ◽  
False Negative ◽  
Fiber Tractography ◽  
Single Voxel ◽  
Ill Posed ◽  
Pass Through

Characterizing and understanding the limitations of diffusion MRI fiber tractography is a prerequisite for methodological advances and innovations which will allow these techniques to accurately map the connections of the human brain. The so-called "crossing fiber problem" has received tremendous attention and has continuously triggered the community to develop novel approaches for disentangling distinctly oriented fiber populations. Perhaps an even greater challenge occurs when multiple white matter bundles converge within a single voxel, or throughout a single brain region, and share the same parallel orientation, before diverging and continuing towards their final cortical or sub-cortical terminations. These so-called "bottleneck" regions contribute to the ill-posed nature of the tractography process, and lead to both false positive and false negative estimated connections. Yet, as opposed to the extent of crossing fibers, a thorough characterization of bottleneck regions has not been performed. The aim of this study is to quantify the prevalence of bottleneck regions. To do this, we use diffusion tractography to segment known white matter bundles of the brain, and assign each bundle to voxels they pass through and to specific orientations within those voxels (i.e. fixels). We demonstrate that bottlenecks occur in greater than 50-70% of fixels in the white matter of the human brain. We find that all projection, association, and commissural fibers contribute to, and are affected by, this phenomenon, and show that even regions traditionally considered "single fiber voxels" often contain multiple fiber populations. Together, this study shows that a majority of white matter presents bottlenecks for tractography which may lead to incorrect or erroneous estimates of brain connectivity or quantitative tractography (i.e., tractometry), and underscores the need for a paradigm shift in the process of tractography and bundle segmentation for studying the fiber pathways of the human brain.

MR-visible water content in human brain: A proton MRS study

1994 ◽  
Vol 12 (8) ◽  
pp. 1237-1244 ◽  
Author(s):  
P. Christiansen ◽  
P.B. Toft ◽  
P. Gideon ◽  
E.R. Danielsen ◽  
P. Ring ◽  
...  
Keyword(s):  
Human Brain ◽  
Water Content ◽  
Proton Mrs ◽  
Mr Visible
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