Diffusion tensor imaging in children and adolescents: reproducibility, hemispheric, and age-related differences.

We evaluated intra-rater, inter-rater, and between-scan reproducibility, hemispheric differences, and the effect of age on apparent diffusion coefficient (ADC) and fractional anisotropy (FA) in healthy children (age range 5.5-19.1 years) examined with a clinical diffusion tensor imaging (DTI) protocol at 1.5 T, using a region of interest (ROI) methodology. Measures of reliability and precision were assessed in six ROIs using two different ROI shapes (polygonal and ellipsoidal). Results: Highly reproducible values of ADC and FA were obtained with the polygonal method on intra-rater (coefficients of variation