Effects of Diffusion Weighting Scheme and SNR on DTI-derived Fractional Anisotropy at 1.5T
Smith S, Prince J, van Zijl P, Mori S, Jones C, Farrell J, Landman B
Kennedy Krieger Institute, Johns Hopkins University School of Medicine
The quantity and composition of DTI data can differ within or between imaging sites, and this impacts the compatibility of DTI-derived results. We investigated how scan repetition and increased directional resolution (number of unique diffusion weighted images in a dataset) impact fractional anisotropy (FA) in a clinical DTI study. By grouping data from 15 DTI datasets in each of three scan sessions, we show that 1) scan repetition alleviates the upward bias in low FA regions observed at low SNR and 2) in an equal scan time comparison FA was not sensitive to diffusion weighting schemes with similar condition numbers.