TY - JOUR
T1 - A majority rule approach for region-of-interest-guided streamline fiber tractography
AU - Colon-Perez, L. M.
AU - Triplett, W.
AU - Bohsali, A.
AU - Corti, M.
AU - Nguyen, P. T.
AU - Patten, C.
AU - Mareci, T. H.
AU - Price, C. C.
N1 - Funding Information:
The authors would like to acknowledge Sam Crowley for his reviews of the manuscript draft. Funding was provided by NIH grants K23 NS060660, RO1 NR014181, and R01 NS082386, as well as the UF Center for Movement Disorder and Neurorestoration and the Brain and Spinal Cord Injury Research Trust Fund of the State of Florida. A portion of this work was performed in the University of Florida McKnight Brain Institute at the National High Magnetic Field Laboratory’s AMRIS Facility, which is supported by National Science Foundation Cooperative Agreement No. DMR-1157490, the State of Florida, and the U.S. Department of Energy.
Funding Information:
Supported by NINDS K23NS60660; NINDS R01 NS082386; NINR R01 NR014181; University of Florida Center for Movement Disorders and Neurorestoration.
Publisher Copyright:
© 2015, Springer Science+Business Media New York.
PY - 2016/12/1
Y1 - 2016/12/1
N2 - Hand-drawn gray matter regions of interest (ROI) are often used to guide the estimation of white matter tractography, obtained from diffusion-weighted magnetic resonance imaging (DWI), in healthy and in patient populations. However, such ROIs are vulnerable to rater bias of the individual segmenting the ROIs, scan variability, and individual differences in neuroanatomy. In this report, a “majority rule” approach is introduced for ROI segmentation used to guide streamline tractography in white matter structures. DWI of one healthy participant was acquired in ten separate sessions using a 3 T scanner over the course of a month. Four raters identified ROIs within the left hemisphere [Cerebral Peduncle (CPED); Internal Capsule (IC); Hand Portion of the Motor Cortex, or Hand Bump, (HB)] using a group-established standard operating procedure for ROI definition to guide the estimation of streamline tracts within the corticospinal tract (CST). Each rater traced the ROIs twice for each scan session. The overlap of each rater’s two ROIs was used to define a representative ROI for each rater. These ROIs were combined to create a “majority rules” ROI, in which the rule requires that each voxel is selected by at least three of four raters. Reproducibility for ROIs and CST segmentations were analyzed with the Dice Similarity Coefficient (DSC). Intra-rater reliability for each ROI was high (DSCs ≥ 0.83). Inter-rater reliability was moderate to adequate (DSC range 0.54–0.75; lowest for IC). Using intersected majority rules ROIs, the resulting CST showed improved overlap (DSC = 0.82) in the estimated streamline tracks for the ten sessions. Despite high intra-rater reliability, there was lower inter-rater reliability consistent with the expectation of rater bias. Employing the majority rules method improved reliability in the overlap of the CST.
AB - Hand-drawn gray matter regions of interest (ROI) are often used to guide the estimation of white matter tractography, obtained from diffusion-weighted magnetic resonance imaging (DWI), in healthy and in patient populations. However, such ROIs are vulnerable to rater bias of the individual segmenting the ROIs, scan variability, and individual differences in neuroanatomy. In this report, a “majority rule” approach is introduced for ROI segmentation used to guide streamline tractography in white matter structures. DWI of one healthy participant was acquired in ten separate sessions using a 3 T scanner over the course of a month. Four raters identified ROIs within the left hemisphere [Cerebral Peduncle (CPED); Internal Capsule (IC); Hand Portion of the Motor Cortex, or Hand Bump, (HB)] using a group-established standard operating procedure for ROI definition to guide the estimation of streamline tracts within the corticospinal tract (CST). Each rater traced the ROIs twice for each scan session. The overlap of each rater’s two ROIs was used to define a representative ROI for each rater. These ROIs were combined to create a “majority rules” ROI, in which the rule requires that each voxel is selected by at least three of four raters. Reproducibility for ROIs and CST segmentations were analyzed with the Dice Similarity Coefficient (DSC). Intra-rater reliability for each ROI was high (DSCs ≥ 0.83). Inter-rater reliability was moderate to adequate (DSC range 0.54–0.75; lowest for IC). Using intersected majority rules ROIs, the resulting CST showed improved overlap (DSC = 0.82) in the estimated streamline tracks for the ten sessions. Despite high intra-rater reliability, there was lower inter-rater reliability consistent with the expectation of rater bias. Employing the majority rules method improved reliability in the overlap of the CST.
KW - Cortico-spinal tract
KW - Majority rules ROI
KW - Semi-manual segmentation
KW - Tractography
UR - http://www.scopus.com/inward/record.url?scp=84947104330&partnerID=8YFLogxK
U2 - 10.1007/s11682-015-9474-5
DO - 10.1007/s11682-015-9474-5
M3 - Article
C2 - 26572144
AN - SCOPUS:84947104330
SN - 1931-7557
VL - 10
SP - 1137
EP - 1147
JO - Brain Imaging and Behavior
JF - Brain Imaging and Behavior
IS - 4
ER -