Dear experts,
I am new to diffusion-weighted imaging. I found that in some “dwifslpreproc” images the frontal part is somewhat distorted (see the examples below). In some cases it looks like both the AP and PA images are visible after reverse PE direction correction. The preprocessing steps include denoising, unringing, as well as eddy-current correction, TOPUP, and reverse PE direction correction using “dwifslpreproc”.
I’m curious about how to call this kind of “artifact” and the reason behind its occurrence. Also, I wonder how much does it affect the subsequent processing and analysis steps (I’m performing FBA and DTI). Actually I proceeded using these images and didn’t find observable fallacies in the FOD and tensor-metric images, but am feeling a bit insecure without figuring out the cause and potential effects of this problem during preprocessing.
Your help would be much appreciated. Thanks!!