# FA measurement using data probe or any other method

**URL:** <https://discourse.slicer.org/t/fa-measurement-using-data-probe-or-any-other-method/9654>\
**Category:** SlicerDMRI\
**Tags:** diffusion\
**Created:** [December 30, 2019, 6:15am UTC](https://discourse.slicer.org/t/fa-measurement-using-data-probe-or-any-other-method/9654 "2019-12-30T06:15:45Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![HariES](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/haries/32/6045_2.png) [@HariES](https://discourse.slicer.org/u/HariES)\
**Post date:** [December 30, 2019, 6:15am UTC](https://discourse.slicer.org/t/fa-measurement-using-data-probe-or-any-other-method/9654/1 "2019-12-30T06:15:45Z")

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How to measure fractional anisotropy in roi after creating scalar maps.

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**Author:** ![pieper](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pieper/32/8_2.png) [@pieper](https://discourse.slicer.org/u/pieper)\
**Post date:** [December 30, 2019, 2:28pm UTC](https://discourse.slicer.org/t/fa-measurement-using-data-probe-or-any-other-method/9654/2 "2019-12-30T14:28:08Z")

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Yes, just mouse of over the slice view when FA volume is visible and you can see the FA value. Or you can segment the area of interest and use the Segment Statistics module to get mean, min, max, etc.

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**Author:** ![HariES](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/haries/32/6045_2.png) [@HariES](https://discourse.slicer.org/u/HariES)\
**Post date:** [February 15, 2020, 6:35pm UTC](https://discourse.slicer.org/t/fa-measurement-using-data-probe-or-any-other-method/9654/3 "2020-02-15T18:35:28Z")

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Dear sir

Thank you and some times FA value appears and sometimes not. What is the problem.  
Segmentation in different slices is not appearing and it accepts only one slice.

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**Author:** ![pieper](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pieper/32/8_2.png) [@pieper](https://discourse.slicer.org/u/pieper)\
**Post date:** [February 16, 2020, 12:43am UTC](https://discourse.slicer.org/t/fa-measurement-using-data-probe-or-any-other-method/9654/4 "2020-02-16T00:43:28Z")

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Hi - you’ll need to give more information in order for use to help you. Maybe include screenshot or two. Also give more details about where you got the data, what format it is in (as best you know), what you tried, what you expected, and what happened instead.

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**Author:** ![HariES](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/haries/32/6045_2.png) [@HariES](https://discourse.slicer.org/u/HariES)\
**Post date:** [February 17, 2020, 11:41am UTC](https://discourse.slicer.org/t/fa-measurement-using-data-probe-or-any-other-method/9654/5 "2020-02-17T11:41:39Z")

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FAvalues not calculated properly. What is the error.  
Screenshot attached.

 ![dtifa](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/0/e/0e177613b2b14c56c37a320972a33dc28d13a635.jpeg)

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**Author:** ![emma1201](https://avatars.discourse-cdn.com/v4/letter/e/9f8e36/32.png) [@emma1201](https://discourse.slicer.org/u/emma1201)\
**Post date:** [March 26, 2022, 7:44am UTC](https://discourse.slicer.org/t/fa-measurement-using-data-probe-or-any-other-method/9654/6 "2022-03-26T07:44:25Z")

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Hi! Apologies for continuing this conversation. I have created an FA Scalar Map using Diffusion \> Quantify \> Diffusion Tensor Scalar Maps and can see the FA using data probe. Is this the FA per voxel?

I also want to find out how to get FA metrics from the Segment Statistics module – do the mean, min, max refer to the FA of the segmented area?

![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/1/5/156b11043dde5c26fbad89987eedc74672618873.png)

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**Author:** ![pieper](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pieper/32/8_2.png) [@pieper](https://discourse.slicer.org/u/pieper)\
**Post date:** [March 26, 2022, 2:00pm UTC](https://discourse.slicer.org/t/fa-measurement-using-data-probe-or-any-other-method/9654/7 "2022-03-26T14:00:47Z")

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> [@emma1201](#):
>
> see the FA using data probe. Is this the FA per voxel?

Yes, it is.

> [@emma1201](#):
>
> FA metrics from the Segment Statistics module – do the mean, min, max refer to the FA of the segmented area?

Yes again.

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**Author:** ![emma1201](https://avatars.discourse-cdn.com/v4/letter/e/9f8e36/32.png) [@emma1201](https://discourse.slicer.org/u/emma1201)\
**Post date:** [March 26, 2022, 5:01pm UTC](https://discourse.slicer.org/t/fa-measurement-using-data-probe-or-any-other-method/9654/8 "2022-03-26T17:01:27Z")

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Thank you so much for the very quick reply! 🙂