Reliability of fiber tracking measurements in diffusion tensor imaging for longitudinal study

Abstract

The statistical reliability of diffusion property measurements was evaluated in ten healthy subjects using deterministic fiber tracking to localize tracts affected in motor neuron disease: corticospinal tract (CST), uncinate fasciculus (UNC), and the corpus callosum in its entirety (CC), and its genu (GE), motor (CCM), and splenium (SP) fibers separately. Measurements of fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (λ 1 ), transverse diffusivity (λ ⊥ ), and volume of voxels containing fibers (VV) were obtained within each tract. To assess intra-rater and inter-rater reliability, two raters carried out fiber tracking five times on each scan. Scan-rescan and longitudinal reliability were assessed in a subset of four subjects who had six scans, with two sets of three scans separated by one year. The statistical reliability of repeated measurements was evaluated using intra-class correlation coefficients (ICC) and coefficients of variation (CV). Spatial agreement of tract shape was assessed using the kappa (κ) statistic.Results-Repeated same-scan fiber tracking evaluations showed good geometric alignment (intrarater κ > 0.90, inter-rater κ > 0.76) and reliable diffusion property measurements (intra-rater ICC > 0.92, inter-rater ICC > 0.77). FA, MD, and λ ⊥ were highly reliable with repeated scans on different days, up to a year apart (ICC > 0.8). VV also exhibited good reliability, but with higher CVs. We were unable to demonstrate reproducibility of λ 1 . Longitudinal reliability after one year was improved by averaging measurements from multiple scans at each timepoint. Fiber tracking provides a reliable tool for the longitudinal evaluation of white matter diffusion properties.

Effect of scanner in longitudinal diffusion tensor imaging studies

“…DTI may be a promising marker to follow longitudinal changes in white matter tracts in normal aging and neurodegenerative diseases. However, for longitudinal studies to be feasible, it is imperative to establish that DTI measurements can be made reliably on individual subjects [Danielian et al, 2010].…”

“…Most studies investigated reliability by performing repeated scans on a few subjects acquired within the same scan session or within short scan intervals. This approach may underestimate the sources of variability relevant for longitudinal studies (e.g., scanner drift) [Danielian et al, 2010]. To our knowledge, there have been no studies that evaluated intra-scanner or inter-scanner reliability using longitudinal data obtained on a large number of subjects.…”

Structural and Functional Neuroimaging in the Investigation of the Brain Neuroplasticity in Post-Stroke Patients (Literature Review)

“…Методы тракто-графии позволяют визуализировать архитектуру волокон, идентифицировать количество, объем, направление волокон, что представляет опреде-ленный интерес в процессе отслеживания восста-новления нервного тракта. Хотя трактография яв-ляется проверенным методом диагностики постин-сультных нарушений [26,27], различные методы анализа могут влиять на интерпретацию результа-тов [27]. Auriat и соавторы выявили, что ДВМРТ и метод ограниченной сферической деконволюции (ОСД) показывают разные результаты у пациентов в хроническую стадию инсульта [28].…”

Automated longitudinal intra-subject analysis (ALISA) for diffusion MRI tractography

“…On the midsagittal slice another ROI is drawn around the splenium of the corpus callosum (F). the scope of this work (e.g., Ciccarelli et al, 2003;Danielian et al, 2010;Malykhin et al, 2008;Pfefferbaum et al, 2003). For each reconstructed fiber bundle, average FA, MD, AD, RD, and tract volume were computed.…”

“…By combining objective protocols for extracting WM fiber pathways of interest on the one hand (Catani and Thiebaut de Schotten, 2008;Wakana et al, 2004Wakana et al, , 2007 and incorporating subjective prior knowledge from the neuroanatomical expert on the other hand, many studies have already demonstrated the high inter-and intrarater reliability and scan-rescan reproducibility of manual FT segmentations (Ciccarelli et al, 2003;Danielian et al, 2010;Heiervang et al, 2006;Kristo et al, 2013,in press;Malykhin et al, 2008;Pfefferbaum et al, 2003;Wakana et al, 2007). The major drawback of manual FT segmentations, however, is that placing ROIs for tract selection can be very labor-intensive and time-consuming, whichfor obvious reasons -can become problematic for large-cohort studies.…”