Quantification of track-weighted imaging (TWI): Characterisation of within-subject reproducibility and between-subject variability

TY - JOUR

T1 - Quantification of track-weighted imaging (TWI)

T2 - Characterisation of within-subject reproducibility and between-subject variability

AU - Willats, Lisa

AU - Raffelt, David

AU - Smith, Robert E.

AU - Tournier, Jacques-Donald

AU - Connelly, Alan

AU - Calamante, Fernando

PY - 2014/2/15

Y1 - 2014/2/15

N2 - Recently several novel image contrasts derived from whole-brain fibre tracking-data (tractograms) have been introduced. The novel contrasts of these track-weighted imaging (TWI) methods may provide important information for clinical neuroscience studies. However, before they can be used reliably to generate quantitative measures, it is important to characterise their within-subject reproducibility, and between-subject variability. In this work we compute the within-subject reproducibility (intra-scan, intra-session and inter-session), and between-subject variability of TWI for a number of different TWI contrasts across multiple subjects. The results are used in simple voxel-wise power calculations within illustrative regions of interest to provide guidelines for required sample sizes and observable effect sizes for individual subjects and between groups. It was found that the required sample sizes and observable effect sizes varied considerably between different TWI maps and for different ROls. For some TWI contrast and ROI combinations, the power calculations yielded clinically practical values. These results provide important information concerning the potential usefulness and sensitivity of TWI maps for individual diagnosis, longitudinal studies and group comparisons, as well as for study designs.

AB - Recently several novel image contrasts derived from whole-brain fibre tracking-data (tractograms) have been introduced. The novel contrasts of these track-weighted imaging (TWI) methods may provide important information for clinical neuroscience studies. However, before they can be used reliably to generate quantitative measures, it is important to characterise their within-subject reproducibility, and between-subject variability. In this work we compute the within-subject reproducibility (intra-scan, intra-session and inter-session), and between-subject variability of TWI for a number of different TWI contrasts across multiple subjects. The results are used in simple voxel-wise power calculations within illustrative regions of interest to provide guidelines for required sample sizes and observable effect sizes for individual subjects and between groups. It was found that the required sample sizes and observable effect sizes varied considerably between different TWI maps and for different ROls. For some TWI contrast and ROI combinations, the power calculations yielded clinically practical values. These results provide important information concerning the potential usefulness and sensitivity of TWI maps for individual diagnosis, longitudinal studies and group comparisons, as well as for study designs.

KW - Diffusion MRI

KW - Fibre-tracking

KW - Track-weighted imaging

KW - Reproducibility

KW - Super-resolution

KW - Track-density imaging

KW - IN-DIFFUSION MRI

KW - SPHERICAL-DECONVOLUTION

KW - INDUCED DISTORTION

KW - TRACTOGRAPHY

KW - BRAIN

KW - IMAGES

KW - DENSITY

KW - FRAMEWORK

KW - ECHO

KW - INTENSITY

U2 - 10.1016/j.neuroimage.2013.11.016

DO - 10.1016/j.neuroimage.2013.11.016

M3 - Article

C2 - 24246491

SN - 1053-8119

VL - 87

SP - 18

EP - 31

JO - NeuroImage

JF - NeuroImage

ER -