Reliability of FA and ADC measures in the healthy brain: implications for longitudinal DTI studies
Ragin A, Edelman R, Storey P, Wu Y, Ochs R, Scheidegger R
Feinberg School of Medicine, Northwestern University, Evanston Northwestern Healthcare
Diffusion tensor imaging (DTI) may have considerable potential in the diagnosis and monitoring of neurological diseases. The inter-session reliability of whole brain, white matter, and gray matter DTI measurements was analyzed across a one year period along with intra-rater, inter-rater, and inter-tool reproducibility. Results show that apparent diffusion coefficient (ADC) measures tended to be more reproducible than fractional anisotropy (FA) measures and agreement for whole-brain measures was higher than for ROI measures. This study supports the feasibility of longitudinal DTI studies of central nervous system disorders, while underscoring the necessity of pre-study standardization of MR sequences and procedures, and inclusion of control subjects.