# DWI Extraction and FOD Processing

**URL:** https://community.mrtrix.org/t/dwi-extraction-and-fod-processing/3938
**Category:** Uncategorized
**Created:** [July 20, 2020, 6:18pm UTC](https://community.mrtrix.org/t/dwi-extraction-and-fod-processing/3938 "2020-07-20T18:18:09Z")
**Posts on this page:** 1
**Showing post:** 2

<div class="post-metadata">

### Author: ![maxpietsch](https://community.mrtrix.org/user_avatar/community.mrtrix.org/maxpietsch/32/25_2.png) [@maxpietsch](https://community.mrtrix.org/u/maxpietsch)
#### Post date: [July 21, 2020, 9:31am UTC](https://community.mrtrix.org/t/dwi-extraction-and-fod-processing/3938/2 "2020-07-21T09:31:27Z")

</div>

> [@soph](#):
>
> normalized DWI files

Have you inspected the normalised DWI data? I’d suspect you see the same scaling issue for all shells which points at normalisation gone wrong. If you used `dwibiascorrect` and have multi-shell data, try `mtnormalise` instead or adjust the N4 options (see for instance [here](https://community.mrtrix.org/t/dwibiascorrect-with-ants-high-intensity-in-cerebellum-brainstem/1338) and [here](https://github.com/MRtrix3/mrtrix3/pull/1328).). If you used `mtnormalise`, make sure the brain mask is very close to or within brain parenchyma.

---

_[View the full topic](https://community.mrtrix.org/t/dwi-extraction-and-fod-processing/3938)._