Article

Intercenter Differences in Diffusion Tensor MRI Acquisition

Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, Scientific Institute and University Hospital San Raffaele, 20132 Milan, Italy.
Journal of Magnetic Resonance Imaging (Impact Factor: 2.79). 06/2010; 31(6):1458-68. DOI: 10.1002/jmri.22186
Source: PubMed

ABSTRACT To assess the effect on diffusion tensor (DT) magnetic resonance imaging (MRI) of acquiring data with different scanners.
Forty-four healthy controls and 36 multiple sclerosis patients with low disability were studied using eight MR scanners with acquisition protocols that were as close to a standard protocol as possible. Between 7 and 13 subjects were studied in each center. Region-of-interest (ROI) and histogram-based analyses of fractional anisotropy (FA), axial (D(ax)), radial (D(rad)), and mean diffusivity (MD) were performed. The influence of variables such as the acquisition center and the control/patient group was determined with an analysis of variance (ANOVA) test.
The patient/control group explained approximately 25% of data variability of FA and D(rad) from midsagittal corpus callosum (CC) ROIs. Global FA, MD, and D(rad) in the white matter differentiated patients from controls, but with lower discriminatory power than for the CC. In the gray matter, MD discriminated patients from controls (30% of variability explained by group vs. 17% by center).
Significant variability of DT-MRI data can be attributed to the acquisition center, even when a standardized protocol is used. The use of appropriate segmentation methods and statistical models allows DT-derived metrics to differentiate patients from healthy controls.

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    • "Obtaining reproducible quantitative results from DTI data is not trivial given that the final results are sensitive to a large number of acquisition and analysis factors (Jones and Cercignani, 2010). Various aspects of DTI reproducibility have been investigated , including basic reproducibility measures of different populations (Bonekamp et al., 2007; Ciccarelli et al., 2003; Heiervang et al., 2006; Marenco et al., 2006), evaluation of the effects of region of interest (ROI) drawing protocols (Wakana et al., 2007), effects of signal averaging (Farrell et al., 2007), head motion effects (Yendiki et al., 2013), as well as the effects of various acquisition parameters like for example b-value (Bisdas et al., 2008), diffusion weighting scheme (Landman et al., 2007; Vaessen et al., 2010), voxel size (Papinutto et al., 2013), and MRI scanner effects (Brander et al., 2010; Pagani et al., 2010; Pfefferbaum et al., 2003; Vollmar et al., 2010; White et al., 2011; Zhu et al., 2011). However, despite the wide use of DTI as a tool to assess white matter integrity in 3 T MRI studies, across-session test–retest reliability of diffusion measures on subjects in stable conditions has not been thoroughly investigated using multiple MRI systems. "
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