Bias in Diffusion Tensor Tissue Integrity Measures Due to Sum of Squares Reconstruction: Characterization and Retrospective Correction

Ken E. Sakaie¹, Kecheng Liu², Mark J. Lowe¹

Diffusion tensor imaging provides quantitative measures of tissue integrity that can be biased by the properties of the noise distribution. Sum of squares is commonly used for reconstructing multi-coil imaging data and exhibits Rician bias for signals near noise floor, leading to substantial bias in diffusivity values. Here, we quantify the bias and demonstrate that a simple but effective correction that can be applied retrospectively.