# Frontal bone thickness within uniform grid

**URL:** <https://discourse.slicer.org/t/frontal-bone-thickness-within-uniform-grid/29239>\
**Category:** Support\
**Created:** [May 2, 2023, 7:41am UTC](https://discourse.slicer.org/t/frontal-bone-thickness-within-uniform-grid/29239 "2023-05-02T07:41:25Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![damiazlkflee](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/damiazlkflee/32/65986_2.png) [@damiazlkflee](https://discourse.slicer.org/u/damiazlkflee)\
**Post date:** [May 2, 2023, 7:41am UTC](https://discourse.slicer.org/t/frontal-bone-thickness-within-uniform-grid/29239/1 "2023-05-02T07:41:25Z")

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Operating system: Windows 10  
Slicer version: 5.2.1  
Expected behavior: Calculating thickness within each grid of a uniform grid.  
Actual behavior: None

Hi. I segmented a frontal bone. I want to put a uniform grid with 20 roi on the bone surface and calculate the thickness in each of 20 roi. then, I want to colour the grid to show the thickness distribution across the bone surface. Can I do that using 3D Slicer?

![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/c/4/c43edd48fdb71df983bcd454e79d5cd8900097bf.png)

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [May 10, 2023, 4:42am UTC](https://discourse.slicer.org/t/frontal-bone-thickness-within-uniform-grid/29239/2 "2023-05-10T04:42:09Z")

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You can use VMTK extension’s Extract centerline module for computing thickness, as it can compute not only a centerline but a medial surface and associated radius value.

You get the radius for the entire medial surface, you are not limited to some lower-resolution grid, but if you need these bins then you can compute statistics for each box: get the point position of each model point, determine which box it corresponds to, and add the radius value to that bin.