Reliability of the corticospinal tract and arcuate fasciculus reconstructed with DTI-based tractography: Implications for clinical practice

Objectives: To assess the reliability of diffusion tensor imaging (DTI)-based fibre tractography (FT), which is a prerequisite for clinical applications of this technique. Here we assess the test-retest reproducibility of the architectural and microstructural features of two clinically relevant tracts reconstructed with DTI-FT. Methods: The corticospinal tract (CST), arcuate fasciculus (AF) and its long segment (AFl) were reconstructed in 17 healthy subjects imaged twice using a deterministic approach. Coefficients of variation (CVs) of diffusion-derived tract values were used to assess the microstructural reproducibility. Spatial correlation and fibre overlap were used to assess the architectural reproducibility. Results: Spatial correlation was 68% for the CST and AF, and 69% for the AFl. Overlap was 69% for the CST, 61% for the AF, and 59% for the AFl. This was comparable to 2-mm tract shift variability. CVs of diffusion-derived tract values were at most 3.4%. Conclusions: The results showed low architectural and microstructural variability for the reconstruction of the tracts. The architectural reproducibility results encourage the further investigation of the use of DTI-FT for neurosurgical planning. The high microstructural reproducibility results are promising for using DTI-FT in neurology to assess or predict functional recovery. Key Points: • Magnetic resonance diffusion tensor fibre tractography is increasingly used in the neurosciences. • The architectural reproducibility of fibre pathways can be up to 69%. • However the microstructural variability of fibre pathways is only 3.4% at most. • The architectural reproducibility results encourage the use of DTI-FT for neurosurgery. • The microstructural reproducibility results support the use of DTI-FT in neurology.