The average pathlength map: A diffusion MRI tractography-derived index for studying brain pathology

Pannek, Kerstin, Mathias, Jane L., Bigler, Erin D., Brown, Greg, Taylor, Jamie D. and Rose, Stephen E. (2011) The average pathlength map: A diffusion MRI tractography-derived index for studying brain pathology. NeuroImage, 55 1: 133-141. doi:10.1016/j.neuroimage.2010.12.010


Author Pannek, Kerstin
Mathias, Jane L.
Bigler, Erin D.
Brown, Greg
Taylor, Jamie D.
Rose, Stephen E.
Title The average pathlength map: A diffusion MRI tractography-derived index for studying brain pathology
Journal name NeuroImage   Check publisher's open access policy
ISSN 1053-8119
1095-9572
Publication date 2011-03-01
Year available 2010
Sub-type Article (original research)
DOI 10.1016/j.neuroimage.2010.12.010
Volume 55
Issue 1
Start page 133
End page 141
Total pages 9
Place of publication San Diego, Calif. ; Sydney
Publisher Academic Press
Collection year 2011
Language eng
Abstract Magnetic resonance diffusion tractography provides a powerful tool for the assessment of white matter architecture in vivo. Quantitative tractography metrics, such as streamline length, have successfully been used in the study of brain pathology. To date, these studies have relied on a priori knowledge of which tracts are affected by injury or pathology and manual delineation of regions of interest (ROIs) for use as waypoints in tractography. This limits the analyses to specific tracts under investigation and relies on the accurate and consistent placement of ROIs. We present a fully automated technique for the voxel-wise analysis of streamline length within the entire brain, the Average Pathlength Map (APM). We highlight the precision and reproducibility of voxel-wise average streamline length over time, and assess normal variability of pathlength values in a cohort of 43 healthy participants. Additionally, we demonstrate the utility of this approach by performing voxel-wise comparison between pathlength values obtained from a patient with a severe traumatic brain injury (TBI, Glasgow Coma Scale Score = 7) and those from control participants. Our analysis shows that voxel-wise average pathlength values are comparable to fractional anisotropy (FA) in terms of reproducibility and variability. For the TBI patient, we observed a significant reduction in streamline pathlength in the genu of the corpus callosum and its projections into the frontal lobe. This study demonstrates that the average pathlength map can be used for voxel-based analysis of a quantitative tractography metric within the whole brain, removing both the dependence on a priori knowledge of affected pathways and time-consuming manual delineation of ROIs.
Keyword Magnetic resonance
Diffusion weighted imaging
HARDI
Quantitative tractography
Constrained spherical deconvolution
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: UQ Centre for Clinical Research Publications
Official 2011 Collection
Centre for Advanced Imaging Publications
 
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Citation counts: TR Web of Science Citation Count  Cited 22 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 25 times in Scopus Article | Citations
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Created: Wed, 22 Dec 2010, 15:24:03 EST by Miss Kerstin Pannek on behalf of Centre for Advanced Imaging