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Tractography of the optic radiation: a repeatability and reproducibility study
Author(s) -
Dayan Michael,
Kreutzer Sylvia,
Clark Chris A.
Publication year - 2015
Publication title -
nmr in biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.278
H-Index - 114
eISSN - 1099-1492
pISSN - 0952-3480
DOI - 10.1002/nbm.3266
Subject(s) - reproducibility , repeatability , diffusion mri , standard deviation , segmentation , mathematics , coefficient of variation , nuclear medicine , artificial intelligence , pattern recognition (psychology) , computer science , statistics , medicine , magnetic resonance imaging , radiology
Our main objective was to evaluate the repeatability and reproducibility of optic radiation (OR) reconstruction from diffusion MRI (dMRI) data. 14 adults were scanned twice with the same 60‐direction dMRI sequence. Peaks in the diffusion profile were estimated with the single tensor (ST), Q‐ball (QSH) and persistent angular structure (PAS) methods. Segmentation of the OR was performed by two experimenters with probabilistic tractography based on a manually drawn region‐of‐interest (ROI) protocol typically employed for OR segmentation, with both standard and extended sets of ROIs. The repeatability and reproducibility were assessed by calculating the intra‐class correlation coefficient (ICC) of intra‐ and inter‐rater experiments, respectively. ICCs were calculated for commonly used dMRI metrics (FA, MD, AD, RD) and anatomical dimensions of the optic radiation (distance from Meyer's loop to the temporal pole, ML‐TP), as well as the Dice similarity coefficient (DSC) between the raters’ OR segmentation. Bland–Altman plots were also calculated to investigate bias and variability in the reproducibility measurements. The OR was successfully reconstructed in all subjects by both raters. The ICC was found to be in the good to excellent range for both repeatability and reproducibility of the dMRI metrics, DSC and ML‐TP distance. The Bland–Altman plots did not show any apparent systematic bias for any quantities. Overall, higher ICC values were found for the multi‐fiber methods, QSH and PAS, and for the standard set of ROIs. Considering the good to excellent repeatability and reproducibility of all the quantities investigated, these findings support the use of multi‐fiber OR reconstruction with a limited number of manually drawn ROIs in clinical applications utilizing either OR microstructure characterization or OR dimensions, as is the case in neurosurgical planning for temporal lobectomy. Copyright © 2015 John Wiley & Sons, Ltd.