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Reproducibility of the Structural Brain Connectome Derived from Diffusion Tensor Imaging.

Bonilha L, Gleichgerrcht E, Fridriksson J, Rorden C, Breedlove JL, Nesland T, Paulus W, Helms G, Focke NK - PLoS ONE (2015)

Bottom Line: The probabilistic approach yielded larger reproducibility, while the individual variation in the number of tracked fibers from deterministic tractography was negatively associated with reproducibility.Anatomical factors and tractography approaches can influence the reproducibility of the structural connectome and should be factored in the interpretation of future studies.Our results demonstrate that connectome mapping is a largely reproducible technique, particularly as it relates to the geometry of network architecture measured by graph theory methods.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Medical University of South Carolina, Charleston, SC, United States of America.

ABSTRACT

Rationale: Disruptions of brain anatomical connectivity are believed to play a central role in several neurological and psychiatric illnesses. The structural brain connectome is typically derived from diffusion tensor imaging (DTI), which may be influenced by methodological factors related to signal processing, MRI scanners and biophysical properties of neuroanatomical regions. In this study, we evaluated how these variables affect the reproducibility of the structural connectome.

Methods: Twenty healthy adults underwent 3 MRI scanning sessions (twice in the same MRI scanner and a third time in a different scanner unit) within a short period of time. The scanning sessions included similar T1 weighted and DTI sequences. Deterministic or probabilistic tractography was performed to assess link weight based on the number of fibers connecting gray matter regions of interest (ROI). Link weight and graph theory network measures were calculated and reproducibility was assessed through intra-class correlation coefficients, assuming each scanning session as a rater.

Results: Connectome reproducibility was higher with data from the same scanner. The probabilistic approach yielded larger reproducibility, while the individual variation in the number of tracked fibers from deterministic tractography was negatively associated with reproducibility. Links connecting larger and anatomically closer ROIs demonstrated higher reproducibility. In general, graph theory measures demonstrated high reproducibility across scanning sessions.

Discussion: Anatomical factors and tractography approaches can influence the reproducibility of the structural connectome and should be factored in the interpretation of future studies. Our results demonstrate that connectome mapping is a largely reproducible technique, particularly as it relates to the geometry of network architecture measured by graph theory methods.

No MeSH data available.


Related in: MedlinePlus

This figure demonstrates each connectome link represented by a line corresponding to the center of mass of the bundle of fibers associated with that link (estimated from deterministic tractography).Each link is color-coded based on its reproducibility per tractography approach and scanner usage. The colorbars indicate the link-wise ICC.
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pone.0135247.g003: This figure demonstrates each connectome link represented by a line corresponding to the center of mass of the bundle of fibers associated with that link (estimated from deterministic tractography).Each link is color-coded based on its reproducibility per tractography approach and scanner usage. The colorbars indicate the link-wise ICC.

Mentions: The anatomical location of link-wise ICCs can be observed in Fig 3, which demonstrates each connectome link represented by a line corresponding to the center of mass of the bundle composed by the fibers included in that link (obtained from deterministic tractography). Each link is in turn color-coded based on its reproducibility per tractography approach and scanner usage. As the figure demonstrates, probabilistic tractography and scanning sessions within the same scanner were associated with a higher number of reproducible links and higher ICCs. In fact, probabilistic tractography was associated with a higher number of links with ICC>0.75 compared with deterministic tractography for images obtained from the same scanner (p<0.0001) and from images obtained from different scanners (p<0.0001). S1 Table provides a comprehensive report of link-wise ICCs and the corresponding white matter areas of tractography streamlines traveled per link.


Reproducibility of the Structural Brain Connectome Derived from Diffusion Tensor Imaging.

Bonilha L, Gleichgerrcht E, Fridriksson J, Rorden C, Breedlove JL, Nesland T, Paulus W, Helms G, Focke NK - PLoS ONE (2015)

This figure demonstrates each connectome link represented by a line corresponding to the center of mass of the bundle of fibers associated with that link (estimated from deterministic tractography).Each link is color-coded based on its reproducibility per tractography approach and scanner usage. The colorbars indicate the link-wise ICC.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4557836&req=5

pone.0135247.g003: This figure demonstrates each connectome link represented by a line corresponding to the center of mass of the bundle of fibers associated with that link (estimated from deterministic tractography).Each link is color-coded based on its reproducibility per tractography approach and scanner usage. The colorbars indicate the link-wise ICC.
Mentions: The anatomical location of link-wise ICCs can be observed in Fig 3, which demonstrates each connectome link represented by a line corresponding to the center of mass of the bundle composed by the fibers included in that link (obtained from deterministic tractography). Each link is in turn color-coded based on its reproducibility per tractography approach and scanner usage. As the figure demonstrates, probabilistic tractography and scanning sessions within the same scanner were associated with a higher number of reproducible links and higher ICCs. In fact, probabilistic tractography was associated with a higher number of links with ICC>0.75 compared with deterministic tractography for images obtained from the same scanner (p<0.0001) and from images obtained from different scanners (p<0.0001). S1 Table provides a comprehensive report of link-wise ICCs and the corresponding white matter areas of tractography streamlines traveled per link.

Bottom Line: The probabilistic approach yielded larger reproducibility, while the individual variation in the number of tracked fibers from deterministic tractography was negatively associated with reproducibility.Anatomical factors and tractography approaches can influence the reproducibility of the structural connectome and should be factored in the interpretation of future studies.Our results demonstrate that connectome mapping is a largely reproducible technique, particularly as it relates to the geometry of network architecture measured by graph theory methods.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Medical University of South Carolina, Charleston, SC, United States of America.

ABSTRACT

Rationale: Disruptions of brain anatomical connectivity are believed to play a central role in several neurological and psychiatric illnesses. The structural brain connectome is typically derived from diffusion tensor imaging (DTI), which may be influenced by methodological factors related to signal processing, MRI scanners and biophysical properties of neuroanatomical regions. In this study, we evaluated how these variables affect the reproducibility of the structural connectome.

Methods: Twenty healthy adults underwent 3 MRI scanning sessions (twice in the same MRI scanner and a third time in a different scanner unit) within a short period of time. The scanning sessions included similar T1 weighted and DTI sequences. Deterministic or probabilistic tractography was performed to assess link weight based on the number of fibers connecting gray matter regions of interest (ROI). Link weight and graph theory network measures were calculated and reproducibility was assessed through intra-class correlation coefficients, assuming each scanning session as a rater.

Results: Connectome reproducibility was higher with data from the same scanner. The probabilistic approach yielded larger reproducibility, while the individual variation in the number of tracked fibers from deterministic tractography was negatively associated with reproducibility. Links connecting larger and anatomically closer ROIs demonstrated higher reproducibility. In general, graph theory measures demonstrated high reproducibility across scanning sessions.

Discussion: Anatomical factors and tractography approaches can influence the reproducibility of the structural connectome and should be factored in the interpretation of future studies. Our results demonstrate that connectome mapping is a largely reproducible technique, particularly as it relates to the geometry of network architecture measured by graph theory methods.

No MeSH data available.


Related in: MedlinePlus