# Strange WM response for dwi2response(msmt\_5tt) at different levels of the b-values

**URL:** <https://community.mrtrix.org/t/strange-wm-response-for-dwi2response-msmt-5tt-at-different-levels-of-the-b-values/797>\
**Category:** Uncategorized\
**Tags:** preprocessing, dwi2response\
**Created:** [March 27, 2017, 12:38pm UTC](https://community.mrtrix.org/t/strange-wm-response-for-dwi2response-msmt-5tt-at-different-levels-of-the-b-values/797 "2017-03-27T12:38:57Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![jiangjiane](https://community.mrtrix.org/user_avatar/community.mrtrix.org/jiangjiane/32/1531_2.png) [@jiangjiane](https://community.mrtrix.org/u/jiangjiane)\
**Post date:** [March 27, 2017, 12:38pm UTC](https://community.mrtrix.org/t/strange-wm-response-for-dwi2response-msmt-5tt-at-different-levels-of-the-b-values/797/1 "2017-03-27T12:38:58Z")

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Hi Community,  
I am getting incomprehensible results for dwi2response (msmt\_5tt).  
With the increase of b-values, the shape of the disc should be smaller and smaller, as shown in the figure below  
 ![](https://community.mrtrix.org/uploads/default/original/1X/bb60c061e62a62cc1157384ff8bad88ab353293b.png)  
But, I am getting strange results, as shown in the figure below(b-values from left to right in the order:0, 1000, 2000, 3000)

 ![](https://community.mrtrix.org/uploads/default/original/1X/ab4f4d4c948f71f60339d68de20d69de7afb1f49.png)  
Any suggestions there?

Cheers,  
Jian

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**Author:** ![jdtournier](https://community.mrtrix.org/user_avatar/community.mrtrix.org/jdtournier/32/2594_2.png) [@jdtournier](https://community.mrtrix.org/u/jdtournier)\
**Post date:** [March 27, 2017, 12:45pm UTC](https://community.mrtrix.org/t/strange-wm-response-for-dwi2response-msmt-5tt-at-different-levels-of-the-b-values/797/2 "2017-03-27T12:45:58Z")

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Again, this is probably due to a limitation in `shview`, which will be fixed in our new release (discussion [here](https://github.com/MRtrix3/mrtrix3/pull/886), if you’re interested). What’s happening is that the scaling of the response is normalised to the first SH coefficient, which is the mean amplitude for that shell. So the profiles you’re seeing are scaled differently here. You can disable the normalisation in the menu, but you’ll then have to scale the display back down quite a lot to see the actual surfaces again (using the mouse scroll function) - they’ll normally show up far too large to actually show at all.

This will all work much more sensibly in our forthcoming release…

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**Author:** ![jiangjiane](https://community.mrtrix.org/user_avatar/community.mrtrix.org/jiangjiane/32/1531_2.png) [@jiangjiane](https://community.mrtrix.org/u/jiangjiane)\
**Post date:** [March 27, 2017, 1:42pm UTC](https://community.mrtrix.org/t/strange-wm-response-for-dwi2response-msmt-5tt-at-different-levels-of-the-b-values/797/3 "2017-03-27T13:42:39Z")

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That makes sense. Expecting forthcoming release.  
Thank you for your answers.

Cheers,  
Jian