On the Battle Between Rician Noise and Phase-Interferences in DWI

Stefan Skare¹, Samantha Holdsworth¹, Rexford D. Newbould², Roland Bammer¹

It has been shown that complex averaging benefits diffusion-weighted imaging (DWI) by reducing the influence of the noise bias in the ADC and DTI. However each component DW image must be phase corrected prior to averaging across diffusion repetitions and directions. The triangular windowing phase correction approach will help to remove phase-related artifacts due to pulsatile brain motion, but a large window radius still result in pronounced Rician noise in the mean DWI data. Here we have reduced the triangular window radius to minimize the amount of Rician noise in the final isotropic-DWI data, without introducing phase cancellations.