# DTI measurements: spherical and linear

**URL:** <https://discourse.slicer.org/t/dti-measurements-spherical-and-linear/29442>\
**Category:** Support\
**Created:** [May 13, 2023, 4:06pm UTC](https://discourse.slicer.org/t/dti-measurements-spherical-and-linear/29442 "2023-05-13T16:06:59Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![mali](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/mali/32/65981_2.png) [@mali](https://discourse.slicer.org/u/mali)\
**Post date:** [May 13, 2023, 4:07pm UTC](https://discourse.slicer.org/t/dti-measurements-spherical-and-linear/29442/1 "2023-05-13T16:07:00Z")

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Dear all,  
after tractography I used my vtk files to extract measurements using Slicer. In the resulting table there are two columns with numbers that I cannot really identify. They are called “spherical” and “linear”. Is this synonymous for radial and axial diffusivity or something else?  
I would really appreciate your help and thank you in advance.  
Best wishes  
Marlene

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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:** [May 17, 2023, 8:33pm UTC](https://discourse.slicer.org/t/dti-measurements-spherical-and-linear/29442/2 "2023-05-17T20:33:32Z")

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Those measures are described in this paper: [Processing and visualization for diffusion tensor MRI - ScienceDirect](https://www.sciencedirect.com/science/article/abs/pii/S1361841502000531)