Multicenter reliability of diffusion tensor imaging.

Area of Science:

• Neuroimaging
• Biomedical Engineering
• Radiology

Background:

• Diffusion tensor imaging (DTI) is increasingly used in multi-site studies.
• The reliability of DTI data across different imaging centers and protocols requires thorough investigation.
• Previous work has established the reliability of anatomical imaging, but DTI reliability is less understood.

Purpose of the Study:

• To assess the reliability of diffusion tensor imaging (DTI) data collected across multiple imaging centers and protocols.
• To quantify intra-subject and inter-site variability for standard DTI scalars.

Main Methods:

• Recruited five healthy controls for imaging at eight different imaging centers.
• Acquired DTI data using two distinct imaging protocols for repeated measures.
• Analyzed standard rotationally invariant DTI measures: fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity.

Main Results:

• Intra-subject coefficient of variation (CV) for DTI scalars was consistently low (<1%).
• Inter-site CV for DTI measures ranged from approximately 1% to 3%.
• Inter-vendor variability was comparable to inter-site variability, influenced by sequence implementation differences.

Conclusions:

• DTI data exhibits high intra-subject reliability.
• Moderate inter-site and inter-vendor variability exists, highlighting the need for standardization in multi-site DTI studies.
• Differences in sequence implementation contribute to observed variability in DTI measures.